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Virtualization: A Beginner’s Guide
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Virtualization: A Beginner’s Guide DANIELLERUEST NELSON RUEST
NewYorkChicagoSanFrancisco LisbonLondonMadridMexicoCityMilan NewDelhiSanJuanSeoulSingaporeSydneyToronto
Copyright © 2009 by The McGraw-Hill Companies. All rights reserved. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher. ISBN: 978-0-07-161402-3 MHID: 0-07-161402-8 The material in this eBook also appears in the print version of this title: ISBN: 978-0-07-161401-6, MHID: 0-07-161401-X. All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringement of the trademark. Where such designations appear in this book, they have been printed with initial caps. McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs. To contact a representative please visit the Contact Us page at www.mhprofessional.com. Information has been obtained by McGraw-Hill from sources believed to be reliable. However, because of the possibility of human or mechanical error by our sources, McGraw-Hill, or others, McGraw-Hill does not guarantee the accuracy, adequacy, or completeness of any information and is not responsible for any errors or omissions or the results obtained from the use of such information. TERMS OF USE This is a copyrighted work and The McGraw-Hill Companies, Inc. (“McGraw-Hill”) and its licensors reserve all rights in and to the work. Use of this work is subject to these terms. Except as permitted under the Copyright Act of 1976 and the right to store and retrieve one copy of the work, you may not decompile, disassemble, reverse engineer, reproduce, modify, create derivative works based upon, transmit, distribute, disseminate, sell, publish or sublicense the work or any part of it without McGraw-Hill’s prior co sent. You may use the work for your own noncommercial and personal use; any other use of the work is strictly prohibited. Your right to use the work may be terminated if you fail to comply with these terms. THE WORK IS PROVIDED “AS IS.” McGRAW-HILL AND ITS LICENSORS MAKE NO GUARANTEES OR WARRANTIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMATION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE, AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. McGraw-Hill and its licensors do not warrant or guarantee that the functions contained in the work will meet your requirements or that its operation will be uninterrupted or error free. Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting therefrom. McGraw-Hill has no responsibility for the content of any information accessed through the work. Under no circumstances shall McGraw-Hill and/or its licensors be liable for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of or inability to use the work, even if any of them has been advised of the possibility of such damages. This limitation of liability shall apply to any claim or cause whatsoever whether such claim or cause arises in contract, tort or otherwise.
Thisbookisdedicatedtoeveryonewhowantstomovetoavirtual infrastructure.There’salotofhypeinthehypervisormarket,andwehope thisbookwillhelpyouwadethroughit.Goodluckwithyourprojects!
ABOUTTHEAUTHORS Danielle Ruest and Nelson Ruest are IT futurists specializing in IT infrastructure optimization and efficiency. They are authors of multiple books, including Microsoft Windows Server 2008: The Complete Reference (McGraw-Hill), the MCITP Self-Paced TrainingKit(Exam70-238):DeployingMessagingSolutionswithMicrosoftExchangeServer 2007andtheMCITPSelf-PacedTrainingKit(Exam70-640):ConfiguringWindowsServer 2008ActiveDirectory(MicrosoftPress),aswellastheVistaDeploymentandAdministration Bible(WileyandSons).TheirnextbookisMCITPSelf-PacedTrainingKit(Exam70-652): ConfiguringWindowsServerVirtualization. DanielleandNelsonhavebeentouringtheUnitedStatesfortwoyears,delivering amulticitytouron“Virtualization:FiveStepsfromPilottoProduction”(http://events .techtarget.com/virtualization2008),whichisdesignedtohelporganizationsmovetoa virtualinfrastructure.Theyhavealsodeliveredseveralfull-daycoursesonvirtualization,mostlyatInteropinLasVegas(www.interop.com).Bothareinvolvedasfreelance writersforseveralITpublications,aswellasproducingwhitepapersforvariousvendors (www.reso-net.com/articles.asp?m=8) and delivering webcasts and conferences (www.reso-net.com/presentation.asp?m=7). NelsonandDanielleworkforResolutionsEnterprises,aconsultingfirmfocusedon ITinfrastructureoptimization.ResolutionsEnterpriseshasbeeninbusinessformore than20yearsandcanbefoundatwww.Reso-Net.com.
AbouttheTechnicalEditors Chris Wolfe is a senior analyst for Burton Group Data Center Strategies. He covers servervirtualizationanddatacenterconsolidation,dataprotection,managementand classification,disasterrecovery,andbusinesscontinuity.PriortojoiningBurtonGroup, Chriswasanationallyrecognizedindependentconsultant,theCISdepartmentheadat theECPICollegeofTechnology,andconsultantwithCommVaultSystems.With14years of experience in virtualization, data protection and recovery, high availability, and enterprisestoragemanagement,Chrisisanindustryleaderinvirtualizationcoverage. Chris also authored Virtualization: From the Desktop to the Enterprise, the first book publishedonthetopic.Hisvirtualizationpresentationsandworkshopsareconsistently amongstthehighestratedsessionsatconferencesinboththeUnitedStatesandEurope. RubenSpruijtworksasSolutionsArchitectatPQR,amajorITcompanythatdesigns, implements,andmigratesadvancedITinfrastructure,andisaMicrosoftGoldCertified Partner,CitrixPlatinumSolutionAdvisor,VMwarePremierandConsultancyPartner intheNetherlands.Inhisjob,RubenisprimarilyfocusedonApplicationandDesktop Delivery, hardware and software virtualization. He is a Citrix Certified Integration Architect (CCIA), Citrix Certified Enterprise Administrator (CCEA), and Microsoft Certified Systems Engineer (MCSE+S). Ruben has been awarded the Microsoft Most Value Professional (MVP), Citrix Technology Professional (CTP), and RES Software ValueProfessional(RSVP).Hehaswrittenseveralarticlesthatcanbedownloadedfrom www.virtuall.eu. DuncanEppingisaseniorconsultantforVMware’sProfessionalServicesOrganization (PSO)intheNetherlands.HismainfocusisServerVirtualization.Healsorunsablogon Yellow-Bricks.comthatmainlydealswithvirtualizationtopics.Hehasextensiveexperiencewithvirtualizationprojectsofallsizesandispassionateaboutthetechnology.
AT A GLANCE PartI
ArchitectforVirtualization
▼ 1 ▼ 2 ▼ 3
TheMovetoVirtualization . . . . . . . . . . . . . . 3 BegintheFive-StepProcess . . . . . . . . . . . . . 13 CompletetheFive-StepProcess . . . . . . . . . . 45
PartII
BuildYourVirtualizationInfrastructure
▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼
4 5 6 7 8 9 10 11 12
PerformaComprehensiveAnalysis . . . . . . . BuildtheResourcePool . . . . . . . . . . . . . . . . BeginwiththeTestingEnvironment . . . . . . WorkwithServerVirtualization . . . . . . . . . . WorkwithVirtualWorkloads . . . . . . . . . . . . ProvisionVirtualMachines . . . . . . . . . . . . . WorkwithDesktopVirtualization . . . . . . . . WorkwithApplicationVirtualization . . . . . WorkwithAppV . . . . . . . . . . . . . . . . . . . . .
65 91 119 153 193 209 233 265 285 vii
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PartIII ▼ ▼ ▼ ▼
13 14 15 16
ConsolidatetheBenefits SecureYourVirtualInfrastructure . . . . . . . . ProtectYourVirtualInfrastructure . . . . . . . . PrepareforBusinessContinuity . . . . . . . . . . UpdateYourManagementStructure . . . . . .
313 355 369 403
▼
Afterword . . . . . . . . . . . . . . . . . . . . . . . . . . . 419
▼
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
CONTENTS Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
PartI ArchitectforVirtualization
▼ 1 TheMovetoVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 InComesVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 BeforeYouBegin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 UseaFive-StepProcess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
▼ 2 BegintheFive-StepProcess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 StepOne:Discovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inventory,Inventory,Inventory . . . . . . . . . . . . . . . . . . . . . . ScanforPotentialVirtualizationCandidates . . . . . . . . . . . . CategorizeServerResources . . . . . . . . . . . . . . . . . . . . . . . . . RationalizeEverything . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14 15 16 21 23
ix
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Step2:Virtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DefiningVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . WhatIsaVirtualMachine? . . . . . . . . . . . . . . . . . . . . . . . . . . ServerVirtualizationModels . . . . . . . . . . . . . . . . . . . . . . . . MajorServerVirtualizationVendors . . . . . . . . . . . . . . . . . . DesktopVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ApplicationVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . WorkwiththeFirstTwoSteps . . . . . . . . . . . . . . . . . . . . . . . . . . .
23 25 30 32 34 39 40 43
▼ 3 CompletetheFive-StepProcess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Step3:HardwareMaximization . . . . . . . . . . . . . . . . . . . . . . . . . . Moveto64-Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RelyonSharedStorage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BeAwareofLicensingCosts . . . . . . . . . . . . . . . . . . . . . . . . . RelyonNewServerFormFactors . . . . . . . . . . . . . . . . . . . . Step4:Architectures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step5:ManageVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . FocusonVMManagement . . . . . . . . . . . . . . . . . . . . . . . . . . RelyontheVirtualizationDecisionFlowchart . . . . . . . . . . . . . . .
46 46 49 51 53 55 57 59 60
PartII BuildYourVirtualizationInfrastructure
▼ 4 PerformaComprehensiveAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 BegintheAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PerformaStorageConsolidationStudy . . . . . . . . . . . . . . . . . . . . ReviewExistingNetworkBandwidth . . . . . . . . . . . . . . . . . . . . . . PerformaPowerandCoolingAudit . . . . . . . . . . . . . . . . . . . . . . . RelyonOtherTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PerformaServerConsolidationStudy . . . . . . . . . . . . . . . . . . . . . IdentifyAppropriatePerformanceMetrics . . . . . . . . . . . . . . InterprettheResults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RationalizeEverythingAgain . . . . . . . . . . . . . . . . . . . . . . . . . . . .
67 71 73 74 81 85 86 88 88
▼ 5 BuildtheResourcePool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 PlanningandPreparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . WhattoVirtualize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ReplaceAnythingBeige . . . . . . . . . . . . . . . . . . . . . . . . . . . . ChoosetheImplementationMethod . . . . . . . . . . . . . . . . . . PreparetheNetworkLayer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NetworkinginVirtualLayers . . . . . . . . . . . . . . . . . . . . . . . . PrepareStorage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PrepareStorageConfigurations . . . . . . . . . . . . . . . . . . . . . . VirtualizeStorage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
92 92 94 95 95 97 99 102 103
Contents
CreateaBackupPlan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best-in-BreedStorage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PrepareHostServers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ServerSizingforResourcePools . . . . . . . . . . . . . . . . . . . . . SizingRecommendationsforResourcePools . . . . . . . . . . . . UpgradingHostServers . . . . . . . . . . . . . . . . . . . . . . . . . . . . RelyonHardware-IntegratedHypervisors . . . . . . . . . . . . . BuildYourOwnHypervisorHardware . . . . . . . . . . . . . . . . TheNextStep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
106 106 107 110 113 114 114 116 117
▼ 6 BeginwiththeTestingEnvironment . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 WorkwithDifferentTestingLevels . . . . . . . . . . . . . . . . . . . . . . . . RelyonVirtualMachineSoftware . . . . . . . . . . . . . . . . . . . . . . . . . PhysicalVersusLogicalWorkspaces . . . . . . . . . . . . . . . . . . . . . . . DefineLabRequirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HostServerConfigurations . . . . . . . . . . . . . . . . . . . . . . . . . VirtualMachineConfigurations . . . . . . . . . . . . . . . . . . . . . . VMUserAccounts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RequiredServerandWorkstationRoles . . . . . . . . . . . . . . . . RequirementsforEachTestingLevel . . . . . . . . . . . . . . . . . . CreatetheLabEnvironment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VirtualMachinesandSoftwareLicensing . . . . . . . . . . . . . . BuildCompleteEnvironments . . . . . . . . . . . . . . . . . . . . . . . VirtualLaboratoryDeliverables . . . . . . . . . . . . . . . . . . . . . . ReuseoftheLabDeliverables . . . . . . . . . . . . . . . . . . . . . . . . . . . . ReuseofDeliverable1:CoreMachines . . . . . . . . . . . . . . . . . ReuseofDeliverable2:DepersonalizedMachines . . . . . . . . ReuseofDeliverable3:TheBaseEnvironment . . . . . . . . . . ReuseofDeliverable4:TheCoreEnvironment . . . . . . . . . . VirtualInfrastructureLaboratoryManagementPractices . . . . . . . SecurityPractices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SpecialBuildProcedures . . . . . . . . . . . . . . . . . . . . . . . . . . . BackupandDisasterRecovery . . . . . . . . . . . . . . . . . . . . . . . LabMaintenanceProcedures . . . . . . . . . . . . . . . . . . . . . . . . VirtualLabBestPracticesSummary . . . . . . . . . . . . . . . . . . . . . . . MoveOntotheVirtualDatacenter . . . . . . . . . . . . . . . . . . . . . . . .
122 124 125 126 126 127 129 129 132 133 135 137 138 142 142 142 144 144 145 146 147 147 148 149 151
▼ 7 WorkwithServerVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 ChooseaServerVirtualizationTechnology . . . . . . . . . . . . . . . . . . TechnologiesandScenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ServerVirtualizationScenarios . . . . . . . . . . . . . . . . . . . . . . . OtherVendorOfferings . . . . . . . . . . . . . . . . . . . . . . . . . . . . VMwareTechnologyComponents . . . . . . . . . . . . . . . . . . . . CitrixVirtualizationTechnologies . . . . . . . . . . . . . . . . . . . . MicrosoftVirtualizationTechnologies . . . . . . . . . . . . . . . . .
155 156 158 160 161 173 176
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Virtualization: A Beginner’s Guide
VirtualMachineFormats . . . . . . . . . . . . . . . . . . . . . . . . . . . VMDiskTypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VirtualizationTechnologyPricing . . . . . . . . . . . . . . . . . . . . . . . . . Market-LeaderHypervisorMetrics . . . . . . . . . . . . . . . . . . . . . . . . Market-LeaderHypervisorPositioning . . . . . . . . . . . . . . . .
180 182 185 187 191
▼ 8 WorkwithVirtualWorkloads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 TheServerVirtualizationDecisionProcess . . . . . . . . . . . . . . . . . . VirtualServiceOfferingsStructure . . . . . . . . . . . . . . . . . . . . . . . . VirtualResourceAllocationRules . . . . . . . . . . . . . . . . . . . . . . . . . RelyonPlacementRules . . . . . . . . . . . . . . . . . . . . . . . . . . . SingleVersusMulti-VMHosts . . . . . . . . . . . . . . . . . . . . . . . WorkwiththeNetworkLayer . . . . . . . . . . . . . . . . . . . . . . . BestPracticesinServerVirtualization . . . . . . . . . . . . . . . . . . . . . .
194 197 200 202 204 206 207
▼ 9 ProvisionVirtualMachines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 BeforeYouBegin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ProvisionNewVirtualMachines . . . . . . . . . . . . . . . . . . . . . . . . . CreateSeedVirtualMachines . . . . . . . . . . . . . . . . . . . . . . . . ProvisionUsingSeedMachines . . . . . . . . . . . . . . . . . . . . . . PhysicalVersusVirtualProvisioning . . . . . . . . . . . . . . . . . . RelyonVirtualAppliances . . . . . . . . . . . . . . . . . . . . . . . . . . VirtualApplianceBenefits . . . . . . . . . . . . . . . . . . . . . . . . . . CreateVirtualAppliancesofYourOwn . . . . . . . . . . . . . . . . PerformPhysical-to-VirtualConversions . . . . . . . . . . . . . . . . . . . P2VPreparationTasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PerformtheP2V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . WorkwithVMwareConverter . . . . . . . . . . . . . . . . . . . . . . . WorkwithPlateSpinPowerConvert . . . . . . . . . . . . . . . . . . . RelyontheUltimate-P2VPlug-inforBartPE . . . . . . . . . . . . MicrosoftConversionTools . . . . . . . . . . . . . . . . . . . . . . . . . ProvisioningBestPractices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
213 215 216 216 217 218 221 222 223 223 225 226 228 229 229 231
▼ 10 WorkwithDesktopVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 WorkwithaSystemStack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DesktopManagementIssues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VistaStateoftheUnion . . . . . . . . . . . . . . . . . . . . . . . . . . . . TheAnatomyofaDesktop . . . . . . . . . . . . . . . . . . . . . . . . . . MovetoDesktopVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . AvailableDesktopVirtualizationProducts . . . . . . . . . . . . . . VirtualDesktopLicensing . . . . . . . . . . . . . . . . . . . . . . . . . . PotentialDesktopVirtualizationScenarios . . . . . . . . . . . . . IdentifyDesktopVirtualizationAudiences . . . . . . . . . . . . .
234 237 237 238 239 240 241 243 246
Contents
CentralizedDesktopVirtualizationInfrastructures . . . . . . . . . . . VMwareVirtualDesktopManager . . . . . . . . . . . . . . . . . . . . CitrixXenDesktop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OtherTechnologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ProfitfromVDI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MajorVendorPositioning . . . . . . . . . . . . . . . . . . . . . . . . . . . MaketheDesktopVirtualizationDecision . . . . . . . . . . . . . .
248 250 257 260 262 264 264
▼ 11 WorkwithApplicationVirtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 ApplicationManagementIssues . . . . . . . . . . . . . . . . . . . . . . . . . . TraditionalApplicationManagementSolutions . . . . . . . . . . RedesignApplicationManagement . . . . . . . . . . . . . . . . . . . . . . . WorkwithaVirtualizationLayer . . . . . . . . . . . . . . . . . . . . . ApplicationStreaming:ANewDistributionStrategy . . . . . BenefitsofAppVfortheOrganization . . . . . . . . . . . . . . . . . . . . .
266 267 272 273 281 283
▼ 12 WorkwithAppV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 CompareApplicationVirtualizationProducts . . . . . . . . . . . . . . . CitrixXenApp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . InstallFreeBridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MicrosoftApplicationVirtualization . . . . . . . . . . . . . . . . . . SymantecSVSPro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VMwareThinApp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MajorVendorPositioning . . . . . . . . . . . . . . . . . . . . . . . . . . . UsetheAppVDecisionProcess . . . . . . . . . . . . . . . . . . . . . . KeyPointsonAppV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IntegrateApplication,Profile,andDesktopVirtualization . . . . . . AssignApplicationsonDemand . . . . . . . . . . . . . . . . . . . . . UseaVolatileDesktopVM . . . . . . . . . . . . . . . . . . . . . . . . . . VirtualizeUserProfiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CreatethePersonalityProtectionStrategy . . . . . . . . . . . . . . FinalizethePersonalityProtectionStrategy . . . . . . . . . . . . . . . . . KeyPointsonthePerfectDesktop . . . . . . . . . . . . . . . . . . . . . . . .
286 290 290 291 291 292 293 293 294 296 297 298 299 301 310 310
PartIII ConsolidatetheBenefits
▼ 13 SecureYourVirtualInfrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 TheCastleDefenseSystem . . . . . . . . . . . . . . . . . . . . ResourcePoolsVersusVirtualServiceOfferings SecureResourcePools . . . . . . . . . . . . . . . . . . . SecureVirtualServiceOfferings . . . . . . . . . . . .
.. . .. ..
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315 317 319 322
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ApplytheCastleDefenseSystemtotheResourcePool . . . . . . . . Layer1:CriticalInformation . . . . . . . . . . . . . . . . . . . . . . . . Layer2:PhysicalProtection . . . . . . . . . . . . . . . . . . . . . . . . . Layer3:OperatingSystemHardening . . . . . . . . . . . . . . . . . Layer4:InformationAccess . . . . . . . . . . . . . . . . . . . . . . . . . Layer5:ExternalAccess . . . . . . . . . . . . . . . . . . . . . . . . . . . . CompletetheResourcePoolSecurityPolicy . . . . . . . . . . . . . . . . .
327 327 330 332 342 346 352
▼ 14 ProtectYourVirtualInfrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 DevelopyourSystemProtectionStrategies . . . . . . . . . . . . . . . . . . UseStandardSystemRecoveryStrategies . . . . . . . . . . . . . . HypervisorManufacturerOfferings . . . . . . . . . . . . . . . . . . . DataProtectionStrategiesforVirtualServiceOfferings . . . . SelectaThird-PartyBackupTool . . . . . . . . . . . . . . . . . . . . . CompletetheRecoveryStrategy . . . . . . . . . . . . . . . . . . . . . . . . . .
356 357 359 366 367 368
▼ 15 PrepareforBusinessContinuity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 BusinessContinuityEssentials . . . . . . . . . . . . . . . . . . . . . . . . . . . MaketheResourcePoolHighlyAvailable . . . . . . . . . . . . . . ProtectYourVirtualServiceOfferings . . . . . . . . . . . . . . . . . MakeVirtualDesktopsHighlyAvailable . . . . . . . . . . . . . . . MakeVirtualApplicationsHighlyAvailable . . . . . . . . . . . . MakeProfilesHighlyAvailable . . . . . . . . . . . . . . . . . . . . . . BuildYourBusinessContinuityStrategy . . . . . . . . . . . . . . . . . . . ProvideMultisiteRedundancy . . . . . . . . . . . . . . . . . . . . . . . AdjustYourServiceLevelAgreements . . . . . . . . . . . . . . . . . BusinessContinuityManagement ThroughReplication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ChoosetheProperReplicationTool . . . . . . . . . . . . . . . . . . . PrepareforSite-BasedDisasters . . . . . . . . . . . . . . . . . . . . . .
370 372 380 387 392 394 394 395 396
397 399 401
▼ 16 UpdateYourManagementStructure . . . . . . . . . . . . . . . . . . . . . . . . . . . 403 LooktoNewAdministrativeRoles . . . . . . . . . . . . . . . . . . . . . . . . MovetoPolicy-BasedWorkloads . . . . . . . . . . . . . . . . . . . . . . . . . Policy-BasedResourceManagement . . . . . . . . . . . . . . . . . . . . . . . LooktoThird-PartyManagementTools . . . . . . . . . . . . . . . . . . . . UpdateYourManagementPractices . . . . . . . . . . . . . . . . . . . . . . .
404 404 408 414 417
▼
Afterword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419 CalculateYourReturnonInvestment . . . . . . . . . . . . . . . . . . . . . . 421
▼
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
FOREWORD V
irtualizationisatechnologywithalengthyhistory,datingbacktowork byIBMinthelate1960sandearly1970s.Thatbeingsaid,it’seasyto findalittleironyinthefactthatyou’restandinghereholdingacopy ofVirtualization:ABeginner’sGuide.Ifvirtualizationhasbeenaroundforso long,whyonearthwouldyouneedabeginner’sguide?Theanswertothat questionisprobablythereasonwhyyou’rereadingthisinthefirstplace. Whathaschangedaboutatechnologythathasexistedfor40years?Virtualization’sintentandcoreconceptsaren’tmuchdifferent,butasitreachestheageof40, onecouldsaythatvirtualizationishavingabitofamidlifecrisis.Ifvirtualization couldgobackandchangeanythingaboutitslife,itturnsoutthatitwouldchange alot.Virtualizationneverreallywantedtobeaproprietarytechnology,limitedto select vendors and very expensive hardware. Instead what virtualization really wantedwastobefreeandopentoanyonewhowantedtouseit,andtobeableto runoncommodityx86hardware. Soifyou’rejustgettingtomeetvirtualization,you’vemetitattherighttime. VirtualizationisnolongerafringetechnologyforIT’srichandfamous,butitisa technologyforeveryone.PracticallyallITshopsusevirtualizationtechnologyin oneformoranothertoday,andvirtualizationisemergingasacorebuildingblock formostITinfrastructures.Formanyorganizations,x86servervirtualizationisa wayoflife.Allnewapplicationsaredeployedasvirtualmachines(VMs)unless theapplicationownercanjustifywhyaphysicalresourceisneeded.
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Virtualizationremovesthephysicalhardwaredependenciesfromserveroperating systems,allowingthemtobemovedandrecoveredlikeneverbefore.Insteadofhaving toperformscheduledhardwaremaintenanceatsomeobscurehourovertheweekend, serveradministratorscannowlivemigrateaVMtoanotherphysicalresourceand performphysicalserverhardwaremaintenanceinthemiddleofthebusinessday.This levelofflexibilityhasallowedmanyofusintheITcommunitytofindsomethingthat hasbeenmissingforaverylongtime—predictabletimeoffandapersonallifetogo alongwithit!Inaddition,I’veworkedwithseveralorganizationsthathadabandoned disasterrecovery(DR)testsbecause“theywerebadformorale.”Discrepanciesin physicalresourcesbetweenproductionandDRsiteswouldmakedisasterrecovery testingextremelycomplexandamassivestraintoITresources.Asyoucanimagine,the hardwareindependencebroughtaboutbyvirtualizationhasremovedthetraditional complexitiesassociatedwithDRandhasallowedmanyorganizationstoreliablytest DRmuchmorefrequentlythantheyeverhad.Infact,I’vefoundthatorganizations usingvirtualizationasacoreelementintheirDRstrategybecamefullyconfidentinthe executionoftheirDRrecoveryplanfortheveryfirsttime. Virtualizationischangingalmosteveryaspectofhowwemanagesystems,storage, networks,security,operatingsystems,andapplications.Makingmattersworse,you nowhavecountlessvirtualizationalternativesatyourdisposal.Weighingtheprosand consofeachchoiceaswellassuccessfullyimplementingandmanagingthemisnoeasy task.ThatiswhyIpersonallyhavefoundthecontentofthisbooksovaluable.Ifirst startedworkingwithx86virtualizationtechnologiesin2000.Backthensomeofmy colleagueswerecallingVMware“VMScare.”It’ssafetosaythatnooneisscaredor laughingnow.Still,whileI’vehadthebenefitofwatchingx86virtualizationmature,I’ve alsowitnessedtheextensivegrowthofcomplexityassociatedwithcorrectlydeploying, securing,andmanagingvirtualinfrastructures.Understandingthenuancesassociated witheachvirtualizationplatformisessentialforsuccessfullydeployingvirtualization solutionsandavoidingthehazardsthataparticularsolutionmaypresent. Ifyou’vemadeitthisfar,Ireallyhopeyoucontinuereading.NelsonRuestand DanielleRuestareITandvirtualizationexpertswhosharetheirimmenseknowledge inthisbook.IhavelongbeenafanofbothNelsonandDaniellebecauseoftheir methodicaleasy-to-digestwritingstyleandtherelevancetoreal-worldproblems containedwithintheirwork.Ifyou’relookingtohitthegroundrunningwithany virtualizationproject,largeorsmall,thisbookisgoingtogiveyouthestartyouneed, andalongthewaywillofferyousomecautionarytalesthatwilleventakesome seasonedvirtualizationveteransbysurprise. —ChrisWolf,SeniorAnalyst,BurtonGroup
ACKNOWLEDGMENTS T
hank you to all of our course and session attendees for helping us makethisbookascompleteaspossible.Yourquestionshavegreatly helpedfleshouttheissuesthatmostanyonemovingtoavirtualinfrastructurewillbeconcernedabout.Also,thankyoutothevendorsincluded inthisbookforbeingsocandidwithinformationontheirproducts.
Thank you to our multiple technical reviewers for their diligent efforts in reviewingthebookandmakingsurethatitstechnicalcontentwasascorrectasit couldbe. Thank you to McGraw-Hill for giving us the opportunity to help IT professionalseverywherebywritingthisbook.Also,thankyoutotheproductionteam formakingthisoneoftheeasiestbookproductionswehaveeverparticipatedin. Keepupthegoodwork!
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INTRODUCTION T
here’sanewwindofchangeintheITindustrytoday.It’scalledvirtualization.Virtualizationinthedatacentercanoccuratseverallevels, butthetypeofvirtualizationthathascreatedthiswindofchangeis guestoperatingsystem(OS)orservervirtualization.GuestOSvirtualizationisasoftwarelayerthatprovidestheabilitytoexposephysicalresources tomakethemavailabletoseveraldifferentvirtualmachinesatthesame time.GuestOSvirtualizationtechnologiescomeintwoflavors.Thefirst isasoftwarelayerthatisusedtosimulateaphysicalmachineontopof anexistingoperatingsystemrunningonahardwarehost.Thesecondisa hypervisor—asoftwareenginethatrunsdirectlyontopofthehardware, eliminatingtheoverheadofasecondaryoperatingsystem. Whicheverversionofservervirtualizationyouuse,itisthisabilitytorunone ormorevirtualmachinesontopofonephysicalhostthathasopenedupallsorts of possibilities in the datacenter. With this technology, it is now much easier to createtesting,training,ordevelopment,andevenproductionenvironments,and turnthemintomalleableentitiesthatrespondtobusinessneedswhentheyappear. Fortraining,development,andtestingenvironments,thistechnologyisespecially usefulbecauseyoucaneasilyresetthemtooriginalsettingswheneverasession hasbeencompleted.Itisalsoeasiertocreatesecurevirtualdesktopenvironments aswellasrelyonvirtualizationtoreducethetotalnumberofphysicalboxesto manage.Inaddition,virtualizationsolvesmost,ifnotall,oftheproblemsorganizationshavealwayshadwithapplicationmanagement.Finally,virtualization opensupvastpossibilitiesintermsofbusinesscontinuity.
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However,bringingallofthesetechnologiestogetherintoasinglecleararchitecture canbeanunrulytaskatbest.Thisiswhatthisbookattemptstodo.Andtomakeiteasier foreveryonetounderstand,ithasbeendividedintothreepartswhichtogether,formthe ABCsofVirtualization. TheABCsofVirtualizationisbasedonthreekeytasks:
▼
artI:ArchitectforVirtualizationbeginstheexplorationofallofthedifferent P virtualizationlayersandhowtheyfittogetherinthemoderndatacenter.Itis composedofthreechapters,eachofwhichoutlinesapartofthefive-stepprogramResolutionshasbeentoutingformorethantwoyearsfortheimplementationofavirtualinfrastructure.
■
art II: Build Your Virtualization Infrastructure begins the build process and P moves you through each of the detailed steps you need to perform to transformyourexistingdatacenterintoadynamicdatacenter,onethatwillrespond dynamicallytoeachofyourbusinessneeds.Chapters4and5helpyoulookat whatneedstochangeatthephysicallayer.Chapter6helpsyougetstartedby outlininghowtotransformyourexistingtraining,testing,anddevelopmentenvironmentsintovirtualinfrastructures.Chapters7,8,and9helpyouimplement servervirtualizationandmoveyourcurrentworkloadsintovirtualmachines. Chapter10detailshowyoucanprofitfromdesktopvirtualization,bothatthe localandatthecentrallevel.Chapters11and12completethissectionbylookingathowyoucantakeadvantageofapplicationvirtualizationtoresolveall ofyourapplicationmanagementissues.Chapter12finishesoffwithalookat howyoublendserver,desktop,andapplicationvirtualizationtogethertocreate volatile virtual desktops that help reduce many of the desktop management woesmostorganizationsfaceonanongoingbasis.
▲
PartIII:ConsolidatetheBenefitscompletesthemovetovirtualizationbylooking athowyourdatacenterhabitschangeonceyouarerunningavirtualinfrastructure.Chapters13and14lookatthesecurityandtheprotectionofyournewly updatedinfrastructure.Chapter15letsyouexaminehowyoucanfinallyresolve businesscontinuityissueswithvirtualinfrastructures,andChapter16closesoff thediscussionwithalookathowmanagementapproachesmustchangenow thatyouarerunningvirtualworkloadsinsteadofphysicalmachines.
Together,thesethreepartsattempttopresentacoherentviewofvirtualization.Thiswill helpyoumoveforwardwithoneofthemostexcitingtechnologiestoappearintheIT world.Virtualizationwillhaveseveralimpactsonyourexistingdatacenter,including:
▼
Theimpactonyournetwork
■
Theimpactonyouroperations
■
Theimpactonyourbusinessprocesses
▲
Theimpactonyourbottomline
Thelastimpactwillbethebest.VirtualizationprojectsareararebreedinITbecausethey actuallypayforthemselvesinashorttime.Nevertheless,theyareprojectsandshouldbe managedassuchifyouwanttogetitrightthefirsttime.
I Architect for Virtualization
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1 The Move to Virtualization
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D
atacentersaroundtheworldarelookingtovirtualizationtechnologiestoreduce their carbon footprint. They are tired of running server systems at 10 percent orlessutilizationratios,yethavingthesesystemscontinuetodrawpowerand require space and cooling just like any other machine. Virtualization promises server hardwareusageratiosof80percentormorewhiledeliveringthesameworkloadsona muchsmallerhardware,andthereforecarbon,footprint. Onceagain,Microsoftistoblameforthesituationmostdatacentermanagersfind themselvesin.Well,it’snotreallyMicrosoft’sfault—thefaultliesinhowpeoplehave cometousethesoftwareMicrosoftproduces,especiallytheiroperatingsystems.MicrosoftWindowsbecamepopularinthedatacenterwiththereleaseofWindowsNTServer inthe1990s.Atthattime,Microsoftwastheunderdogandcompetedheavilytomakeits serveroperatingsystem(OS)acceptedinenterprisedatacenters.Thisisnojoke.Some governmental jurisdictions even went as far as implementing binding rulings, stating thatMicrosoftWindowswasnottobeusedforserverornetworkingworkloadsatany time.Thesameoccurredinmanycorporations.Penetratingthedatacenterwasanuphill battleforMicrosoftalltheway,butWindows’abilitytodelivernetworkedservicesatthe sametimeasitsupportedapplicationexecutionwasacompellingofferingthatnoone couldresist.Therestishistory.Today,mostdatacentersrunsomeversionofWindows ontheirservers. Buthowdidtheseserversgettoa10percentorlessutilizationratio?Well,mostly itwasWindowsNT’sfault.AstheydeployedthisserverOS,administratorsdiscovered thatWindowsNTwasamonolithicoperatingsystem.Sincemanyoperations,especially application operations, were performed at the kernel level of the OS, administrators quicklydiscoveredthatwhenanapplicationfroze,itwouldoftenfreezetheentireOS andcauseaBlueScreenofDeath(BSOD)fortheserverasawhole.Asaconsequence, peoplestartedcreatingsingle-purposeserverswhentheydeployedworkloadsonWindowsNT.Asthenameimplies,asingle-purposeserverwillonlyrunasingleapplication. If the application fails and causes the server to fail, it will not disrupt any other applicationthatmaybeco-hostedontheserver.Thisapproachquicklytrickleddown toend-usercustomers.Ifabusinesscustomerwantedtointroduceanewtechnologyto meetanewbusinessneed,oneofthefirstthingstheywouldstateisthattheydidnot wanttoshareworkloadswithanyoneelsejusttomakesuretheirapplicationwasnot impacted by any other. This quickly led to massive server proliferation, with projects oftenintroducingseveralproductionserverswhenimplementingnewtechnologies,as wellasintroducingadditionalserversinsupportoftestanddevelopmentenvironments. Based on these approaches, datacenters everywhere quickly saw Windows and other serversproliferate. Over time, Microsoft solved the monolithic OS problem as they delivered everincreasinglypowerfulversionsofWindowsServer,butpeople’shabitsdidn’tchange alongwiththeOS.Stilltoday,end-usercustomersrefusetohavetheirapplicationhosted onthesameserverasanother,statingthattheycannottrustthestabilityoftheother application,oreventhattheydonotwanttoloseservicebecauseanotherapplication willhaveadifferentupdateschedulethantheirs.Becauseofthis,administratorsare oftenforcedtodeployadditionalphysicalservers,eveniftheyknowbetter.
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Chapter 1:
The Move to Virtualization
Habitsaren’ttheonlyreasonwhythereissomuchserversprawl.Applicationvendors oftenrequiretheirapplicationstobeisolatedinordertosupportthem.Inaddition,securityandnewcompliancerequirementsarealsocausesforapplicationisolation.Themore applicationsyoufindonaserver,thelargertheattacksurfaceonthatserver.Inthiscase, administratorsdon’thaveachoice;theymustisolatesystemsandcreatemoreservers. Windowsisnolongertheproblem;itispeople’sperceptionsandlong-termhabits thatneedtochange.Andtheyneedtochangefast,withspacequicklybecomingapremiuminthedatacenter,coolingsystemsbeingoverrunbythesheernumberofphysical servers, and power costs soaring through the roof because of the rising cost of non- renewableresources. Whilemanypeoplerunmixedoperatingsystemsintheirdatacenters,itismostlybecausetheyrunWindowsserversthattheyneedtoconsidersomeformofconsolidation, oftenthroughvirtualization.ItisnotbecauseofUNIXorLinux,eventhoughthesinglepurposeserverscenariohasoftenspilledoverontotheseoperatingsystemsaswell.More than76percentofserversbeingvirtualizedtodayrunsomeformofMicrosoftWindows (source:EnterpriseStrategyGroupBrief,MicrosoftWillTurnUptheServerVirtualizationVolumein2008,January2008).Youcanexpectthisnumbertogrowasvirtualization becomesmainstreamthisyearandthenext.Virtualizationisapowerfulsolutionforsupportinganyx86servertransformation,includingWindows,UNIX,andLinux.
INCOMESVIRTUALIZATION Analystscansaywhattheywant,butprovidinginformationtechnology(IT)servicesis abigjob.AccordingtotheanalystfirmGartner,morethan70percentofITbudgetsare spentoninfrastructure,andinmanycases,thenumberscanbeevenworse,especially beforeconsolidationand/oroptimizationprojects. Thisiswherevirtualizationcanhelp.Mostadministratorswilllooktoservervirtualizationtohelpreducethephysicalfootprintoftheirdatacenter.Butmovingtoavirtualizeddatacenter,whateveritssize,ismorethanjustdeployingavirtualizationengine andconvertingsomephysicalservers.Likeanynewtechnology,virtualizationrequires seriousthoughtandconsiderableplanningbeforeitcandeliverthebenefitsadministratorshavecometoexpectfromit.Infact,whenyouplanforvirtualization,youshould answerthefollowingquestions:
▼ Whatisvirtualization?
■ Whywouldweneedit?
■ Howcanitimprovemybusiness?
■ Whattypesofvirtualizationtechnologiesexist?
■ WhichtermsshouldIbefamiliarwith?
■ Whatisthecost/benefitratioofvirtualization?
■ Whatnewchallengeswillitbringtothedatacenter?
■ HowshouldIstructuremyvirtualizationsolution?
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Virtualization: A Beginner’s Guide
■ Whichapplicationsorservicesaregoodvirtualizationcandidates?
■ Whichserverplatformsorformfactorsarebestsuitedtosupportvirtualization?
▲ AmImissinganythingelse?
Thisisthefocusofthisbook:tohelpyouanswerthesequestionsasyoupondervirtualizationandthepotentialbenefitsitcanofferyourorganization. AccordingtoZiff-DavisResearch,February18,2008,thereareseveralcommonvirtualizationdrivers(seeFigure1-1),withthemostcommonbeingtheloweringofhardware costsandanimprovementinserverutilizationratios.Thereisnodoubtthatthemajor factordrivingthemovetovirtualizationisservervirtualization,yetitisn’ttheonlydatacenterlayerthatcanbevirtualized. In a survey released in January 2008, the Enterprise Strategy Group found that of 341 respondents, all of them intended to deploy virtualization solutions in the future (see Figure 1-2), and more than 70 percent of them intended to do it within the next 12months.InanothersurveyreleasedinDecember2007,thesameresearchfirmfound thatofalloftherespondents(365)alreadyrunningavirtualsolution,morethan70percent of them were relying on VMware (see Figure 1-3). Of course, this second survey was releasedwellbeforeMicrosoftenteredthefraywithitsbuilt-invirtualizationsolution withWindowsServer2008Hyper-V.Today,theseresultsmaybedifferent,butonething iscertain:Everydatacenterintheworldwillmakesomeuseofvirtualizationsolutions inthenextfiveyears.Ifyou’reusingsomeformofx86orx64technology,virtualization isdefinitelyinyourfuture. Thefirstplacetostartistogainafullunderstandingoftheconceptsinherentindatacentervirtualizationandwhattheymaymeantoyoufromnowon.
Figure1-1. Commonvirtualizationdrivers
/Ruest/401-X/Chapter1
Chapter 1:
Figure1-2. Servervirtualizationplannedadoption
Figure1-3. Primaryservervirtualizationsolutions
The Move to Virtualization
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Virtualization: A Beginner’s Guide
BeforeYouBegin Withtherisingcostofenergy,moreandmoreorganizationsfeeltheneedtomovetoa greenerdatacenter,onethatwilluseareducedamountofspaceandareducedamount ofenergyandcoolingtohostasmallernumberofphysicalservers.Asmentionedpreviously,thiscanbeachievedthroughtheuseofvirtualizationtechnologieswithinthe datacenteratserver,workstation,andapplicationlevels.Thebenefitsfaroutweighthe disadvantagessincetheonlygoodphysicalserveroperatingat10percentcapacityisa serverthathasbeentransformedintoavirtualmachine. Power and utility companies also see the benefit from machine virtualization, since theircustomerscangreatlyreducetheirpowerandcoolingconsumptionratios,ensuring thatcurrentpowergenerationfacilitiescanlastlongerandaddresstheneedsofalarger communityofusers.Thisiswhymanyofthemhavedevelopedrebateprogramsfororganizationsimplementingvirtualizationprojectsandremovingphysicalserversfromtheir datacenters.ThefirsttodosowasCalifornia’sPacificGas&Electric(PG&E),whichdevelopedarebateprogramthatcouldsaveorganizationsupto$4millionpersiteforaserver virtualizationprojectandintroduceditonNovember8,2006.Incentivescanrangefrom $150to$300perserver,withtheprogrambeingcappedat50percentoftotalprojectcosts. PG&EpioneeredthiseffortwithvirtualizationmanufacturerVMwareCorporation. NOTE For the PG&E Rebate Program announcement, go to www.pge.com/about/news/ ediarelations/newsreleases/q4_2006/061108.shtml. For more information on the PG&E Rebate Program, go to www.ge.com/mybusiness/energysavingsrebates/incentivesbyindustry/hightech/ hteeincentives.shtml. Today,PG&Eisnottheonlyutilitycompanythatofferssuchrebates.Infact,rebates areavailablefromanumberofdifferentsources,includingfederal,state,andmunicipal governments,aswellasutilityfirms.Onegoodsourceofinformationonpower-saving rebatesistheGoodtoBeGreenWebsite.ThissiteincludesaWeb-enabledmapofthe U.S.(seeFigure1-4).Tofindpotentialrebatesinyourarea,simplyclickonyourstateand thendrilldowntotherebateprogramsthatmayapplytoyou. NOTE ToaccesstheGoodtoBeGreenUSAmap,gotowww.goodtobegreen.com/financialincentives .aspx#nc. Ifyoufindthatnovirtualizationrebateprogramisofferedinyourarea,youcanwork withyourvirtualizationvendorandyourutilitycompanytohelpdevelopone.Mostutilityfirmshaveanurgentneedtoreducethepowerconsumptionlevelsofthedatacenters theyserveandwillbemostwillingtomovetowardsthecreationofsucharebateprogram. Theyhaveastakeinthis,too.Utilityorganizationswanttomakesurethedatacentersthat arehousedintheirgridremainintheirgridandremainascustomers.Inaddition,they wanttomakethemostefficientuseoftheenergytheyprovideandmanage.Sotothem,it makeseconomicsensetohaveorganizationsbothstayintheirgridandconsumeenergy moreefficiently.
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Chapter 1:
The Move to Virtualization
Figure1-4. TheGoodtoBeGreenWeb-enabledUSAmapofrebateprograms
However, whether you work with the utility firm to create a program or you rely onanexistingprogram,youwillfindthatyoumustapplyforthisprogrambeforeyou beginthevirtualizationproject.Here’swhy:
▼ T heutilityfirmmustperformapowerconsumptionanalysisbeforethe virtualizationprojectbegins.Thiswillidentifyhowpowerisbeingusedin thedatacenterthroughtraditionalconsumptionmethods.
■ T heutilityfirmwillperformaninitialanalysisonpotentialpowerconsumption reductionsthroughvirtualizationandusethisasthebaselinefortheproject go-ahead.
■ Y ouperformyourvirtualizationprojectandtransformphysicalserversinto virtualmachines,reducingthepowerconsumptionlevels.
■ Apost-projectassessmentisperformed.
▲ T hepost-projectassessmentiscomparedtotheinitialbaseline,andnewpower consumptionlevelsareidentified.Anydiscrepanciesbetweentheoriginal baselineandthefinalresultswillbeadjusted,andfinalmonieswillbeprovided totheproject.
Forthisreason,youmustcontactyourutilityfirmbeforeyoubeginyourproject;otherwise,theywillbeunabletodeterminepreviousconsumptionratesanddeterminethe potentialsavingsinenergyyoucouldbenefitfrom.
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Virtualization: A Beginner’s Guide
BuyingGreenTechnologies Of course, when you transform your datacenter to turn the majority of your physical systemsintovirtualmachines,youwillmostlikelybereplacingsomeofthehardware componentsinyourinfrastructure.Sinceoneofthemajorreasonsyouareperforming thisprojectistoreducethecarbonfootprintofyourdatacenter,youshouldmakeapoint ofcontinuinginthisveinandmakingitoneofyourdatacenter’sunderlyingprinciples. Greeningthedatacentermeansmorethanjustreducingthenumberofphysicalservers containedwithinit.Itmeansmovingforwardwithgreenpoliciesandpractices.Oneof thebestoftheseistheacquisitionpracticesinsupportofnewmachinepurchases. AnotherWebsitewithafocusongreenITtechnologiesistheElectronicProductEnvironmentalAssessmentTool(www.EPEAT.net),whichwasdevelopedoverthecourse ofatwo-yeareffortthankstoaninitialgrantprovidedbytheU.S.EnvironmentalProtectionAgency(EPA).EPEATdevelopedasetofcriteriainordertohelpdeterminethe environmentalimpactofinformationtechnologyequipment.Itproducedasetofcriteria thatisdividedintothreecompliancemodels:Bronze,Silver,andGold.Productsfitinto eachcategorybasedoncompliancewiththefollowingcriteria:
▼ Bronzeproductsmeetalloftherequiredcriteria.
■ S ilvermeetsalloftherequiredcriteriaandmeets50percentoftheoptional criteria.
▲ Goldmeetsalloftherequiredcriteriaandalloftheoptionalcriteria.
EPEATmaintainsalistofapprovedequipment(seeFigure1-5)ontheirWebsiteinadditiontoprovidingaseriesofresourcesforequipmentbuyers—resourcessuchassupport for request for proposal (RFP) criterion creation, model RFPs to use, and help during acquisitionprocesses.
Figure1-5. TheEPEATRegisteredProductsSearchToolisconstantlyupdatedasnewproducts qualifyineithertheBronze,Silver,orGoldcategories.
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Chapter 1:
The Move to Virtualization
NOTE For more information on the required and optional EPEAT criteria, go to www.epeat.net/ Criteria.aspx. Relying on EPEAT to buy green complements the virtualization project because it furthersyoureffortstoreducelong-termpowerconsumptionratios.
GreenAssetDisposal Another “green” aspect of your virtualization project will be the disposal of superfluous equipment.As you move through your project and replace existing physical systemswithvirtualmachines,youwillneedtofindwaystodisposeofthemachines younolongerneed.Inmanycases,you’llfindthatyoucanreusemuchofthehardwareyouarereducing.Butifthepurposeofyourvirtualizationprojectistoreduce yourcarbonfootprint,itdoesn’tmakesenseforyoutoreusealloftheequipmentyou arereplacing.Inaddition,youmustfindwaystosecurelywipeinformationandintellectualpropertyfromthesystemsyouwillgetridof.Mostorganizationsalreadyhave secureinformationprotectionplansforobsoletehardware,butfewhaveagreenasset disposalprogram. Asaconsequenceofthenewmovetowardsgreentechnologies,newserviceshave been developed to help organizations achieve both goals: secure asset disposal while reducingthecarbonfootprintofthedisposalprocessitself.AsimplesearchontheInternetwilllocateseveralservicesthatofferbothgreenandsecuredisposal,butoneofthe most popular services is Green Asset Disposal (www.greenassetdisposal.com), which specializesinthistypeofsystemdisposal.GreenAssetDisposalwillrecycle,remarket, andevenpurchasetheassetsyouneedtopasson.Theyofferapickupservicetofacilitate yourdisposal,andwillalsoprovideyouwithinformationonhowtoproperlydisposeof technologiesrangingfromservers,PCs,andotherobsoleteITequipment. Ifyou’regoinggreen,makesureyourelyongreendisposalprocedurestogetthe mostgreenforyourbuck.
USEAFIVE-STEPPROCESS LikeanyotherITproject,virtualizationprojectsmustbestructured.Overthecourseof thelasttenyears,ResolutionsEnterprisesandtheauthorsofthisbookhavedeveloped astrategyforthemovetovirtualization.Thisstrategyhasbeentestedthroughamultitudeofdeliveryprojects,aswellasthroughaseriesofpresentationsthroughoutthe U.S.andCanada.Thepresentationsweredeliveredthroughtwomulticitytours,oneon serverconsolidationin2007andoneonvirtualizationin2008,aswellasseveralfull-day coursesonthetopic.Ineachcase,attendeesandclientorganizationsfoundthisstrategy tobesoundanddirect,aswellasavaluableaidintheirownmovetovirtualization.
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Virtualization: A Beginner’s Guide
AccordingtoResolutions,themovetovirtualizationreliesonfivekeysteps:
1. D iscovery Thefirststepbeginswithdatacenterinventoriesandthe identificationofpotentialvirtualizationcandidates.
2. V irtualization Thesecondstepfocusesongainingacompleteunderstanding ofthevaluechoicesthatvirtualizationcanoffer.
3. H ardwaremaximization Thethirdstepfocusesonhardwarerecoveryand howyoucanmakejudicialinvestmentswhenaddingnewhardwareorreplacing oldersystems.
4. A rchitecture Thefourthsteplookstothearchitectureyoumustprepareto properlyintroducevirtualizationtechnologiesintoyourdatacenterpractices.
5. M anagement Thelaststepfocusesontheupdateofthemanagementtools youusetomaintaincompletevirtualizationscenariosinyournewdynamic datacenter.
Each of these building blocks brings you one step closer to a complete virtualization solution. Virtualization is much more than simply loading a virtualization technology on a serverandtransformingoneortwoworkloadsintovirtualmachines.Inordertomakethe mostofyourvirtualizationproject,youmustlearnhowdifferentvirtualizationsolutions fittogether,whateachvendoroffers,andwhatyouactuallyneedtoimplementtomake themostofvirtualizationtechnologiesinyourdatacenterwhileaddressingyourbusiness needs.TheResolutionsFive-StepProcesswillgreatlyassistyouinthisendeavor.
2 Begin the Five-Step Process
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hapter 1 introduced the Resolutions Five-Step Process. This process helps you begintounderstandthevaluepropositionvirtualizationcanoffertoyourorganization.Thefirststep,Discovery,letsyouidentifywhatisinyourorganization’s networkandgivesyouaviewofhowitcouldbetransformed.Steptwo,Virtualization, beginstheintroductionofthevariousvirtualizationtechnologiesandleadsyouthrough anunderstandingofhowtheyintegratetogethertocreatethedynamicdatacenter.
STEPONE:DISCOVERY Oneoftheelementswehavebeenabletoconfirmthroughoutourmulticitytoursisthat ITadministratorsdonotlikeinventories.That’sright.Onaverage,about15percentofthe thousandsofpeopleinvolvedinourtoursactuallyhadanup-to-dateinventoryinhand, yettheinventoryisanabsolutemustwhenyou’redealingwithIT.Howcanyoumanage whatyoudon’tknowyouhave?Howcanyoumovetovirtualizationifyoudon’tknow howmanyserversyouarerunningandwhattheirpurposeinyournetworkis? WeallknowthatthereasonmostITadministratorsarelookingtoservervirtualization isbecauseofthedatacentercrunch.Thereisnomoreroomintoday’sdatacenters.Addingmoreserversalwaysrequiresmorepowerinputaswellasmorecooling.Datacenter upgradesareexpensive.Whymoveforwardwiththemifyoudon’tactuallyneedthem? Inaddition,physicalserversarehardtoprovision.PeopleusingWindowsserversrun allsortsoftechnologies,fromdiskimagingtoWindowsDeploymentServices(WDS),to trytoreducetheoverheadofpreparingaphysicalserver.Andwhentheserverisfinally provisioned,you’llfindoutthattheacquisitioncostwashighonlytoruntheentirehardwarecollectionatlessthan15percentutilization.What’sworse,whenitcomestimeto protectthesystemandtheapplicationsitrunsfromdisasterrecovery,you’llhavetoget involvedinanexpensivebusinesscontinuitysolution—replicatingthedatacontained withinthisservertoamirrorinstallationinaremotesite.Whocanaffordthis?Yetwe knowthatmorethan80percentoforganizationsthatsufferatotalITfailurewillnot recoverandwillgounder.Thisisasignificantrisktorun. PCsarealsoaproblem.Feworganizationswanttotakethetimetoupgradetheirsystemstonewversionsoftheoperatingsystem.JustlookatwhathappenedtoVista.More than90percentofalltheattendeesofourtourdidnotmovetoVistaandhavenointention ofdoingso.Everyoneiswaitingforthenextversionoftheoperatingsystem(OS).Inaddition,morethan75percentofourattendeesarelettingtheirusersrunPCswithadministrativerights.Nowondertheyhavenoendofissueswiththeirworkstationsandmobile systems.TheissuesarecompoundedwithPCsbecauseoftheirverynature.PCsaredistributedthroughouttheentireorganization,ineverysite,ineverylocation,ontheroad, andeveninemployees’homes.Thismakesthemevenhardertomanageandrepair. Applicationsalsohavetheirfairshareofissues.Applicationconflictsconstantlyarise nomatterwhatITadministratorsorapplicationdevelopersdotoavoidthem.Microsoft hasreleasedtheWindowsInstallerservicetoprotectsystemsfromapplicationchanges, butcreatingWindowsInstallerfilesisacomplexprocessthattakestimeandcostsmoney. Buttheworstisthedeploymentmodeleveryonerelieson:Pushingthousandsofbitsto
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alloftheendpointsintheorganizationisdefinitelynotthebestpracticewhenitcomesto systemrepairorevenlicensemanagement.Therehastobeabetterway.Andthereis.
Inventory,Inventory,Inventory It’samazingjusthowmanyorganizationsdonotknowwhatthecontentoftheirinfrastructureis.Yet,thisisthemostimportantsteptoanyvirtualizationproject.Knowing thecontentofyournetworkcanhelpyoumaintainitaswellascontrolitsgrowth.Ifyou don’tknowwhatyouhave,howcanyoumakesureyoucanprotectitandadministerit, or,evenworse,transformitintoadynamicdatacenter? Can’tbebotheredtogoouttobuyaninventoryproductandthendeployit?Don’t havethetimetoprepareaninventory?Don’tworry.Oneoftheeasiestwaystogenerate aninventoryofyournetworkistoworkwithfreetools.Forexample,manypeopleuse theMicrosoftBaselineSecurityAnalyzer(MBSA)toscantheirnetworksforvulnerabilitiesandrequiredupdates.MBSAiseasytosetupandrunagainstallofthesystemsin yourinfrastructure.Onceascaniscomplete,MBSAprovidesyouwithinformationon eachsystemitscanned,includingInternetProtocol(IP)address,operatingsystem,installedapplications,and,ofcourse,vulnerabilities.Youcaneasilyturnthisvaluabledata intoaninventorybylinkingtheresultsofanyMBSAscanwithMicrosoftVisiothrough theMicrosoftVisioConnectorforMBSA.Visiowillautomaticallygenerateagraphical imageofyournetworkanddisplaydetailedinformationoneachdevicewhenyouclick onit(seeFigure2-1).Withthesetoolsinhand,youcouldgenerateyourfirstinventoryin afewseconds!You’llbeamazedatwhatyou’llfind.
Figure2-1. UsingtheVisioConnectorforMBSA
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NOTE FormoreinformationonMBSA,gotohttp://technet.microsoft.com/en-us/security/cc184925 .aspx.aspx.TodownloadtheVisioConnectorforMBSA,gotowww.microsoft.com/downloads/details .aspx?FamilyID=8EA27D78-32B5-4F37-A7FD-99EE2AA76C62&displaylang=en.
NOTE Microsoft also offers aVisio Connector for System Center Operations Manager (SCOM). YoucanuseSCOMtocreateavisualrepresentationofyournetwork.TodownloadtheSCOMVisio Connector,gotohttp://technet.microsoft.com/en-us/security/cc184925.aspx.
ScanforPotentialVirtualizationCandidates MBSAisnottheonlyfreetoolyoucanusetoperformyourinitialanalysis.Microsoft alsoprovidestheMicrosoftAssessmentandPlanning(MAP)ToolkitSolutionAccelerator.MAPisatoolthatcanbeusedtoscanyourentirenetworkforassessments.Itwas formerlyreleasedastheWindowsVistaHardwareAssessmentToolandwasdesigned toalloworganizationstoscantheirexistingPCstodeterminetheirpotentialforhosting theVistaOS.Microsoftsoonrealizedtwothings.First,noonewasmovingtoVista.And second,ifthetoolcouldscanforVistahardwarerequirements,itcouldalsoscanfora widevarietyofassessments.Therefore,Microsoftchangedandadaptedthetooltosupportawholeseriesofotheroperations. NOTE ForaccesstoMAP,gotowww.microsoft.com/downloads/details.aspx?FamilyID=67240b763148-4e49-943d-4d9ea7f77730&displaylang=en. MAPisanagentlessanalyzerthatcollectsinformationonalloftheidentifiedsystems.ItworksmostlyonWindowssystemsandrequirestheuseofanaccountthathas administrativeprivilegesoneachtargetcomputer.MAPcanberunfromanysystem, butshouldpreferablybeinstalledonanadministrativeworkstation.InstallationisperformedthroughaWindowsInstallerfile.Twofilesareavailable:oneforx86or32-bit systems,andoneforx64or64-bitsystems.Onceinstalled,MAPwillrelyonWindows ManagementInstrumentation(WMI),theRemoteRegistryService,oreventheSimple NetworkManagementProtocol(SNMP)toidentifythesystemsonyournetwork.AssessmentsincludedinMAPinclude(seeFigure2-2):
▼ DatabasesystemsthatcanbemigratedtoSQLServer2008
■ S ystemsandservicesthatcanbemigratedtoMicrosoftOnlineServices(mostly forsmallbusinessesorremoteoffices)
■ E nvironmentsthatcanprofitfromNetworkAccessProtection(NAP)ortheuse ofForefrontsecuritytechnologies,aswellasgeneralsecurityreports
■ Power-savingproposalstoreducepowerconsumptionindatacenters
■ SystemsthatcanrunVistawithServicePack1
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■ SystemsthatcanrunMicrosoftOffice2007
■ SystemsthatcanrunWindowsServer2008
■ ServerrolesthatcanbemigratedtocorrespondingWindowsServer2008roles
■ Performancereportsfromserversorworkstations
■ S erverconsolidationthroughvirtualizationwithMicrosoftHyper-Vand WindowsServer2008
■ ApplicationsthatcanbevirtualizedthroughMicrosoftApplicationVirtualization
▲ Potentialoptimizeddesktopscenarios
Eachassessmentprovidesacomprehensiveseriesofreportsbasedonthepurposeof theassessment. Default reports are in English, but can be localized in French, German, Japanese, Korean,Spanish,andBrazilianPortuguese.ReportdetailswilldependonthetypeofreportyouuseMAPtorun.Forexample,runningaMAPreportforWindowsServer2008 readinesswillincludedetailsaboutapproveddriversandrequiredhardwareupdates. Reports on server virtualization will identify current workloads and potential candidatesforvirtualization(seeFigure2-3). NOTE MicrosoftisconstantlyimprovingMAP.Theremaybemanymorereportsavailablethrough itbythetimeyoureadthis.
Figure2-2. UsingMAPtoperformsystemassessments
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Figure2-3. ViewingMAPreports
Microsoftisnottheonlyvendortooffersolutionsforsystemassessment.VMware, thefounderofx86virtualization,alsoofferstwotoolsthatcanbeusedforanassessment oftheserversthatcouldbetransformedintovirtualmachines.Thefirstandmostreadily availabletoallusersisVMwareGuidedConsolidation(VGC).VGCisavailableasan integralpartofVMwareVirtualCenter(seeFigure2-4),themanagementinterfaceused tocontrolbothphysicalhardwareandvirtualmachinesrunningonVMwaretechnology. VGCperformsitsanalysisthroughthreekeysteps:
1. F irst,itreliesonanagentlessinfrastructuretodiscoverexistingcomputersand collectperformanceinformationfromthem.
2. S econd,itanalyzescollecteddataforhardwareconsolidationsuitabilityand recommendsapotentialconsolidationplan.
3. I tallowsyoutoconvertmachinesfromphysicaltovirtual(P2V)installations throughtheVMwareConverter.
VGCisapowerfultoolthatissuitablefornetworkswithfewerthan100physical servers.Whiletheanalysiscanbeperformedonalivenetworkwithlittleimpact—since theengineisagentless,itdoesnotaddoverheadtoaproductionserver’sworkload— consolidationshouldbetestedinalaboratoryfirstbecauseitisthemostcomplicated part of any virtualization project. If possible, you should perform your conversions when servers are offline to protect existing services and maintain your service level agreements(SLAs)withendusers.
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Figure2-4. UsingVMware’sGuidedConsolidationengine
ObtaintheVMwareGuidedConsolidationbydownloadinganevaluationversionof VMware’sVirtualCenter.Evaluationslast60days,whichisappropriatesinceitwillgive youenoughtimetoproperlyanalyzeyournetwork. NOTE VMwareVirtualCenterisincludedaspartofVMwareInfrastructure.Toobtainanevaluation copyofVirtualCenter,gotowww.vmware.com/download/.Anevaluationserialnumberwillberequired torunthetool.YouwillreceiveitonceyouregisterontheWebsite.
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For networks with more than 100 servers, rely on VMware’s Capacity Planner to analyzeyourserverresources.Unfortunately,CapacityPlanner,whilefreetouse,isnot readilyavailabletoendusers.InordertoperformascanusingCapacityPlanner,another agentlesstool,youmusteithercontractVMwareProfessionalServicesorhaveaconsultingpartnerperformtheanalysis.Theanalysisitselfismostoftenfree,anditwillprovide extensiveinformationabouttheserversyoucanconsolidate. CapacityPlannerwillgiveyoureportsonserverprocessorutilization(seeFigure2-5), aswellasacomprehensivereportthatwillidentifypotentialvirtualizationcandidates. Analysis results include CPU, memory, network, and disk utilization on a server-byserverbasis. However, like many, you may fear vendor bias when a reseller comes in with CapacityPlanner.Ifthisisthecase,youmayprefertorelyonCiRBA’sDataCenter IntelligenceorPlateSpin’sPowerRecontoolssincetheycanmodelseveralvirtualizationenvironments.Inaddition,CiRBA’stoolcanalsoperformwhat-ifanalysisona numberofdifferentserverplatformsinordertodeterminethebesttargetplatformfor avirtualizationproject,whilePlateSpin’swillalsoincludepowerreductionoptions intheanalysis. NOTE For more information on CiRBA’s Data Center Intelligence tool, go to www.cirba.com. MoreinformationonPlateSpinPowerReconcanbefoundatwww.platespin.com/products/powerrecon/. YoucandownloadafreeversionofPowerReconwhichwillsupportanalysisofupto100servers.
Figure2-5. UsingVMware’sCapacityPlannertool
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Unliketheothertoolsmentionedhere,CiRBA’stoolcanalsotakeintoaccountnontechnicalfactorsthatimpacttheconsolidation.Forexample,site,department,security zonerestrictions,maintenancewindows,andservice-levelrequirementsallplayarole indeterminingtheeventualconsolidationplan.However,thetoolsthatonlycollectperformancedatacannotaccountforanyofthenon-technicalelementsintheconsolidation project. Without this information included in the analysis, you have to account for it manually.UsingatoollikeCiRBA’swillletyoufactortheseelementsintoyourcomputationsandprovideabetteroverallviewofwhereyouneedtobe. PowerReconontheotherhandwillmonitorupto2,000serversatonceandifyou combinethecommercialversionofthistoolwithPlateSpinPowerConvert,youwillbe abletoautomatetheconversionprocessonceyouranalysisiscomplete. Other tools are available, but the most common are MAP, VGC, VMware CapacityPlanner,CiRBA’s,andPlateSpin’s.Keepinmindthatwhichevertoolyouuse,you mustruntheanalysisovertime.Yourintentistoidentifywhichsystemsarerunning, whentheyneedresources,howmanyresourcestheyrequire,whenresourcesareata lowthreshold,andwhentheypeak.Forthisreason,youshouldruntheanalysisforat leastonemonth.Runningitforthisperiodoftimewillatleastgiveyouthehighandlow utilizationratiosforeachserverduringamonthlycycle.Theanalysiswillnotidentify peaksandlowsforlongerperiods,forexample,forapplicationsthatpeakonaquarterly orsemi-annualbasis.Keepthisinmindwhenyoureviewtheresultsofyouranalysis. NOTE Beverycarefulduringthisanalysisbecauseitwillformthebasisofyourfutureinfrastructure. Properlyidentifyingtherequiredresourcesforeachserverworkloadwillallowyoutoproperlysize thehardwareyouwillmovetheseworkloadstoonceyouvirtualizethem.Youcanneverbetoocareful when you perform a virtualization candidate analysis because once you virtualize your systems, informationonphysicalresourcerequirementsfortheseworkloadswillnolongerbeavailable. You also want to time your analysis as closely as possible to the implementation. It’s always agoodpracticetoreanalyzeanenvironmentafewweeksbeforetheimplementation.Ifthereisa significantgapbetweenthetimeyouperformtheanalysisandthetimeyoumoveforwardwiththe project,youmayfindthatnewapplicationrequirementsthatwerenotcapturedintheearlieranalysis willbemissedaltogether.
CategorizeServerResources Onceyouhavetheresultsofyouranalysis,youcancategorizeeachmachineroleinto groups.Forexample,youcanidentifytheserverrolesorfunctionsinthefollowingservicetypes:
▼ Networkinfrastructureandphysicalservers Theseserversprovidecore networkingfunctions,suchasIPaddressingornameresolution,including supportforlegacysystems.Theyalsoprovidevirtualprivatenetworks(VPNs) androutingandremoteaccessservices.And,becausetheyareabase-level service,theyrunthevirtualizationroleonphysicalmachines.
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■ I dentitymanagementservers Theseserversarethecoreidentitymanagers forthenetwork.Theycontainandmaintaintheentirecorporateidentity databaseforallusersanduseraccessthroughLightweightDirectoryAccess Protocol(LDAP)services.ForWindowsServer2008,thesewouldbeservers runningActiveDirectoryDomainServices.Thisfunctionshouldnotbeshared withanyotherasmuchaspossible,unlessitisacorenetworkingfunction, suchasnameresolutionthroughtheDomainNameSystem(DNS).
■ F ileandprintservers Theseserversfocusontheprovisionofstorageand structureddocumentservicestothenetwork.Thesefunctionsformthebasis ofinformationsharingwithinproductivitynetworks.
■ A pplicationservers Theseserversprovideapplicationservicestotheuser community.SomeexampleswouldbeExchangeServer,SQLServer,andso on—infact,anyservicerunningwithinproductivitynetworks.
■ T erminalservers Theseserversprovideacentralapplicationexecution environmenttousers.Usersneedonlyhaveaminimalinfrastructureto accesstheseserversbecausetheirentireexecutionenvironmentresideson theserveritself.
■ D edicatedwebservers TheseserversfocusontheprovisionofWebservices tousercommunities.Forexample,inWindowsServer,theWebEditionis specificallydesignedtomeettheseneeds.
▲ Collaborationservers Theseserversprovidetheinfrastructurefor collaborationwithintheenterprise.Examplesoftheseservicesinclude WindowsSharePointServices,streamingmediaservices,andunified communications.
Serverscanbefurthercategorizedaccordingtotheirlocationandservertype.For example,theserversyouuseintheheadquartersdatacenterwillnotbethesametypeas thoseyouuseinremoteoffices.Also,ifyouusetower,rack-mounted,orbladeservers, you should identify this in your analysis. Applications or workloads can be further categorizedintothefollowinggroups:
▼ Commercialversusin-houseorcustomapplications
■ Legacyversusupdated
■ Infrastructureapplications
■ Supporttothebusiness
■ Lineofbusiness(LOB)
▲ Mission-criticalapplications
Eachoftheseapplicationcategorieswillbeusefulwhenyoumovetovirtualization.
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RationalizeEverything Afteryoucompletetheevaluationofthesystemsyouhaveinplace,youwillbereadyto moveontowardsvirtualization.However,itisimportantthatyoudistinguishbetween serverandphysicalconsolidation.Serverconsolidationmeansreducingthenumberof serversinyourdatacenter,creatinglargerserversthathostmultipleworkloads.Yetin mostcases,organizationsthatperformavirtualizationprojectwillnotperformserver consolidation;theywillperformphysicalconsolidation.Takethefollowingexample. OrganizationAhas100physicalservers.Afterperforminganextensiveanalysisand selectingthevirtualizationenginetouse,OrganizationAdeterminesthattheycantransformeachandeveryexistingworkloadintoavirtualmachine.Todoso,theymustuse 10physicalmachinestorunthe100virtualizedworkloads.Theresult?Onehundredten servers.Thisisnotaserverconsolidationproject.Itisaphysicalconsolidationproject.Of course,OrganizationAwillprofitfromthemovetovirtualizationbecausetheywillhave 90fewermachinestomanage,buttheiradministratorswillnothavelessworksincethey nowhavetomanage10moremachinesthanbefore. Thisiswhyrationalizationisthemostimportantaspectofanyvirtualizationproject. Yourgoalshouldbetohavefewerserverswhenyoufinishthevirtualizationprojectthan whenyoubegan,andthisshouldincludethephysicalserversyouwillneedtorunthe virtualmachinesyoucreate.Thereisnobettertimetoperformaserviceorworkload consolidationorrationalizationthanwhenyouaremigratingtoanewvirtualizedinfrastructure.Keepthefollowingquestionsinmindasyouscanthroughtheresultsofyour analysis:
▼ Whatistheutilizationratioforeachmachine?
■ A rethereany“parked”machines—machinesthatbelongtospecificuser groupsbutthatarenotconstantlyused?
■ Arethereanyobsoletemachines?
■ Isthereanywaytocombineworkloads?
▲ Isthereanyotherwaytoreducethemachinefootprint?
Howwellyouaddressthesequestionsandapplytheiranswerswilldeterminejusthow manymachinesyouwillbeleftwithonceyoucompleteyourproject.
STEP2:VIRTUALIZATION Asyougatherinformationaboutyoursystems,youcanmoveontostep2andbeginto learnaboutthedifferentvirtualizationtechnologiesandhowtheycanhelpsolvespecific businessissuesinyourorganization.Possiblythebestplacetostartiswithvirtualization itself. According to Merriam-Webster’s online dictionary (www.merriam-webster .com/home.htm), virtual reality is “an artificial environment which is experienced through sensory stimuli (as sights and sounds) provided by a computer and in which
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one’sactionspartiallydeterminewhathappensintheenvironment.”Thisisexactlywhat happenswithvirtualization:Virtualmachinesoftwarecreatesoneormorevirtualworkstationsorserversonareal,physicalsystem(seeFigure2-6).Everythingdependsonwhat isavailableontherealmachine:harddiskspace,processorcapability,networkinterface cards,andamountofrandomaccessmemory(RAM).Thevirtualmachinesyoucreate withvirtualizationsoftwarecansupporttheinstallationandoperationofanynumberof operatingsystems,includingallversionsofMicrosoftWindows,MS-DOS,Linux,some formsofUNIX,andsoon—basicallyanyx86-basedoperatingsystem,eventhoserunning onthex64extensionofthisplatform.Theycancommunicatewiththephysicalhostand othermachinesonthenetworkjustasiftheywererealmachinesintheirownsense. Physicalmachinepartitioninghasbeenaroundsincethe1960swhenIBMbeganpartitioningtheirmainframeserverstohostmultipleinstancesoftheiroperatingsystem.In thiscase,thepartitioningtechnologywasusedtorunmultiple,orratherparallel,instancesofthesameoperatingsystem.WhileIBMinventedsystempartitioning,itwasn’tuntil the1990sthatthistypeofpartitioningwasintroducedtothex86processorarchitecture. Itwasalsoatthistimethatphysicalsystempartitioningwasrenamedvirtualization.This typeofvirtualizationwasfirstintroducedtoletendusersrunoperatingsystemssuch asWindowsonotherplatforms,suchastheAppleMacintosh.Infact,in2003,Microsoft acquiredFrenchcompanyConnectix,whichspecializedindesigning“virtualmachine” softwaretorunWindowsoperatingsystemsonMacintoshcomputers,givingMacintosh usersaccesstothethousandsofapplicationsavailableontheWindowsplatform.This beganMicrosoft’sfrayintotheworldofmachinevirtualization.
Figure2-6. UsingavirtualmachineinVMwareWorkstation
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Microsoftwaslate,ofcourse,becauseVMwareCorporationhadbeenworkingwith machinevirtualizationsincethelate1990sthroughtheintroductionofVMwareWorkstation,anend-user–orientedproductthatwasdesignedtoletyourunanynumberof additional instances of an x86 operating system. VMware then realized the power of virtualizationandmovedittotheserverlevel,beginningthemassiveboominmachine virtualizationweseetoday.NowVMwareisthemarketleaderinvirtualizationandoffersthebroadestspectrumofsolutionsfordatacentervirtualization. Intheend,IBM’smachinepartitioningwasmuchlikeXerox’sinventionofthemouse andthegraphicalinterface.XeroxinventedthesetechnologiesintheirPaloAltoResearch Center(PARC)manyyearsbeforetheybecamepopularized,butitwasApple,notXerox,thatgainednotorietyforthetwotools.Today,manypeoplethinkbothinventions originatedwithApple,butinfact,Appleonlyborrowedfromexistinginnovationsand repackagedthemintoaformatthatwouldhavebroadappeal.Thesameoccurredwith VMwareandIBM’soriginalsystem-partitioningtechnology.WhileIBMhadtheoriginal idea,itwasVMwarethatputtheideaintopracticeinsuchawaythatitquicklybecame popularandisnowabillion-dollarindustryofitsown.ThekeytoVMware’ssuccessis thatunlikeIBM,VMware’svirtualizationtechnologyletsyourunavarietyofdifferent operatingsystems.Inaddition,itletsyourunthemoninexpensivecommodityhardware,whichputsthetechnologywithinthereachofanyITdepartment. The ability to run multiple virtual machines on top of a single physical machine makesthistechnologyexcitingindeedforanyonewhoneedstocreate,setup,andreuse machinesrunningalmostanyoperatingsystem.ThisiswhatgivesVMware-likevirtualizationitsbestvalue.
DefiningVirtualization Today,virtualizationtechnologyhasevolvedandcannowapplytomultiplelayerswithinthedatacenter.Thisiswhyitisimportanttofullyunderstandwhichtypesofvirtualization are available. In a dynamic datacenter—one that takes full advantage of the valuepropositionsofvirtualization—therewillbeatleastsevenlayersofvirtualization (seeFigure2-7).
▼ ServerVirtualization(SerV)isfocusedonpartitioningaphysicalinstance ofanoperatingsystemintoavirtualinstanceorvirtualmachine.Trueserver virtualizationproductswillletyouvirtualizeanyx86orx64operatingsystem, suchasWindows,Linux,andsomeformsofUNIX.Therearetwoaspectsof servervirtualization:
■ SoftwareVirtualization(SoftV)runsthevirtualizedoperatingsystemon topofasoftwarevirtualizationplatformrunningonanexistingoperating system.
■ HardwareVirtualization(HardV)runsthevirtualizedoperatingsystem ontopofasoftwareplatformrunningdirectlyontopofthehardware withoutanexistingoperatingsystem.Theengineusedtorunhardware virtualizationisusuallyreferredtoasahypervisor.Thepurposeofthis engineistoexposehardwareresourcestothevirtualizedoperatingsystems.
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Figure2-7. Thesevenaspectsofvirtualization
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Whenworkingwithservervirtualization,thephysicalserverbecomesa hostforallofthevirtualoperatingsystemsorvirtualmachines(VMs),which becomeworkloadsrunningontopofthishost.
■ S torageVirtualization(StoreV)isusedtomergephysicalstoragefrom multipledevicessothattheyappearasonesinglestoragepool.Thestorage inthispoolcantakeseveralforms:directattachedstorage(DAS),network attachedstorage(NAS),orstorageareanetworks(SANs);anditcanbelinked tothroughseveralprotocols:FibreChannel,InternetSCSI(iSCSI),Fibre ChannelonEthernet,oreventheNetworkFileSystem(NFS).Thoughstorage virtualizationisnotarequirementforservervirtualization,oneofthekey strengthsyouwillbeabletoobtainfromstoragevirtualizationistheabilityto relyonthinprovisioningortheassignationofalogicalunit(LUN)ofstorageof agivensize,butprovisioningitonlyonanas-neededbasis.Forexample,ifyou createaLUNof100gigabytes(GB)andyouareonlyusing12GB,only12GB ofactualstorageisprovisioned.Thissignificantlyreducesthecostofstorage sinceyouonlypayasyougo(seeFigure2-8).
■ N etworkVirtualization(NetV)letsyoucontrolavailablebandwidthby splittingitintoindependentchannelsthatcanbeassignedtospecificresources. Forexample,thesimplestformofnetworkvirtualizationisthevirtuallocal areanetwork(VLAN),whichcreatesalogicalsegregationofaphysical network.Inaddition,servervirtualizationproductssupportthecreationof virtualnetworklayerswithintheproductitself.Forexample,usingthisvirtual networklayerwouldletyouplaceaperimeternetworkonthesamehostas otherproductionvirtualworkloadswithoutimpactingeitherofthenetworks orlettingthevirtualmachinesaccesseachother.
Figure2-8. UsingthinprovisioningthroughStorageVirtualizationcansignificantlyreducestorage costs.
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■ M anagementVirtualization(ManageV)isfocusedonthetechnologies thatmanagetheentiredatacenter,bothphysicalandvirtual,topresent onesingleunifiedinfrastructurefortheprovisionofservices.ManageVis notnecessarilyperformedthroughasingleinterface.Forexample,inlarge datacenters,youwillwanttodividedifferentservicedeliveriesintolayers andseparateoperationsbetweenthem.Insmallerdatacenters,youmaynot havethestafftodividetheresponsibilities,butyoushouldatleastensurethat administratorsweardifferent“hats”whentheyworkwiththevariouslayers ofyourarchitecture.Infact,youshouldmakesurethattwokeylayersare segregatedatalltimes:
■ R esourcePools(RP),whichincludesthecollectionofhardwareresources— hostservers,racks,enclosures,storage,andnetworkhardware—thatmakes upthedatacenterinfrastructure
■ V irtualServicesOfferings(VSO),orworkloadsthataremadeupofthe virtualmachines—serversand/ordesktops—thatareclient-facingandoffer servicestoendusers Onekeyfactorinthissegregationisthecreationofdifferentsecuritycontexts betweenresourcepoolsandVSOs.Sinceyouradministrativeteamsarenotthe sameanddonothavethesameresponsibilities—resourcepooladministrators mustensurethatproperresourcesareavailableforVSOs,andVSOadministrators mustensurethatproperservicesaredeliveredtoendusers—youlimitthe possibilityofcontaminationfromthevirtualtothephysicalworldbyusing completelydifferentsecuritycontextsbetweenthetwo. Forexample,yourphysicallayershouldusestrongpasswordsandensure thatallcommunicationsbetweenmanagementconsolesandphysicalhosts areencryptedatalltimesbecausepasswordsarecommunicatedoverthese links.Yourvirtuallayershouldalsousetheseprinciples,butinaddition,itwill provideasecuritycontextforusersthatwillnotrelyonsuchstringentpolicies. Insomeinstances,thesegregationofphysicalandvirtuallayersisperformed automatically.ThisoccurswhenyourunaWindowsinfrastructureintheVSO butuseanon-Windowshypervisorintheresourcepool.Ifyouusethesame OSatbothlayers,makesureyouconsciouslycreateseparatesecuritycontexts betweenthetwo.
■ D esktopVirtualization(DeskV)allowsyoutorelyonvirtualmachinesto provisiondesktopsystems.Desktopvirtualizationhasseveraladvantages, theleastofwhichistheabilitytocentralizedesktopdeploymentsandreduce distributedmanagementcostsbecauseusersaccesscentralizeddesktops throughavarietyofthinorunmanageddevices.
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NOTE In the end of 2008,VMware acquired technology from a company calledTrangoVirtual Processorsinordertomovevirtualizationbeyondthedesktoptomobilehandsets.VMware’sMobile VirtualizationPlatform(MVP)isdesignedtocreateavirtuallayeronmobilehandsetstoallowyouto runmultiplemobilesystemsonthesamehandset.Forexample,youcouldrunoneplatformforwork andanotherforpersonaluse.Inaddition,byvirtualizingthemobilehandset,VMware’sMVPwillmake iteasierforyoutomoveyourpersonalsettingsfromphonetophone.WatchformoreonMVPin2009 andbeyond.
■ P resentationVirtualization(PresentV),untilrecentlycalledTerminalServices, providesonlythepresentationlayerfromacentrallocationtousers.Whilethe needforPresentVisdiminishingbecauseoftheintroductionoftechnologies suchasApplicationVirtualization,theprotocolsusedforPresentVareatthe forefrontofbothDeskVandSerVtechnologiessincetheyaretheprotocols usedtoaccess,use,andmanagevirtualworkloads.
▲ ApplicationVirtualization(AppV)usesthesameprinciplesassoftwarebasedSerV,butinsteadofprovidinganenginetorunanentireoperating system,AppVdecouplesproductivityapplicationsfromtheoperatingsystem. AppVtransformsthedistributedapplicationmanagementmodelbecause youonlyneedtovirtualizeanapplicationonce.Fromthenon,theapplication virtualizationenginewillmakethevirtualizedapplicationrunonanyversion ofWindows.What’sevenbetteristhatproductssuchasAcressoSoftware’s AdminStudio(www.acresso.com/products/licensing/adminstudio.htm) willtakealloftheapplicationsyouhavealreadypackagedtorunwiththe WindowsInstallerServiceinMSIformatandconvertthemtoAppVformats overnightinabatchprocess.AdminStudiosupportsboththeCitrixandthe VMwareAppVformats.TransformyourapplicationsintoAppVformat,and you’llneverhavetotouchthemagain!WorkisalsobeingdonebymajorAppV vendorssuchasMicrosoft,Citrix,InstallFree,Symantec,andVMwaretoapply AppVtoserverapplications.WhileAppVonlyworksonthe32-bitplatform rightnow,workisalsobeingdonetomakeitworkon64-bitorx64platforms. Bothserver-basedAppVandx64AppVmaybeavailablebythetimethisbook getsintoprint. NOTE You can also create successful application virtualization deployments with some Solaris and Linux applications.Vendors such as Data Synapse,Trigence, andTransitive have had some success leveraging application virtualization on Linux and Solaris applications, especially in the financialsector.
Whiletherearesevenlayersofvirtualization,thereareotherkeytermsthatmakeup thelanguageofvirtualizationinthedatacenter.Theseinclude:
▼ Hostserver Thephysicalserverrunningvirtualmachineworkloads.
■ G uestoperationsystem Avirtualizedoperatingsystemrunningasaworkload onahostserver.
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■ R esourcePool Thecollectionofhardwareresources,includinghostservers thatmakeupthedatacenterinfrastructure.
■ V irtualServiceOfferings Thevirtualmachinesthatareclient-facingand offerservicestoendusers.Theyarealsooftenreferredtoasvirtualworkloads.
■ V irtualAppliances(VAPs) Pre-packagedVSOsthatrunaspecific applicationorworkload.
■ P olicy-basedworkloads VSOsthatarepowereduponanas-neededbasis throughautomatedpolicies.
▲ Operatingsystemvirtualization OftenmisconstruedasguestOS virtualization,thisisnothingmorethanOSpartitioningbecauseitcan onlyrunonesingleOStypeinparallelinstances.Thevalueofthistypeof “virtualization”islimitedbecauseyoumusthaveaneedtoruntheparticular OS.ProductsofthistypeincludeSolarisContainersandParallelsVirtuozzo Containers,whichrunstheVirtuozzoOS—aversionofLinux—inparallel.
Nowthatyouunderstandmostofthekeyterms,let’sdelveintowhateachofthethree corevirtualizationtechnologies—SerV,DeskV,andAppV—canbringtothedatacenter.
WhatIsaVirtualMachine? As you now know, virtualization is a technology that partitions a computer into severalindependentmachinesthatcansupportdifferentoperatingsystemsandapplications running concurrently. The great advantage of this is that you can take a physicalserverthatisrunningat10percentutilizationandtransformitintoonerunningat60to80percentutilizationbyloadingitupwithmultiplevirtualmachines. Theunderlyinghypervisorsoftwarewillrundirectlyonthehardwareandactasa coordinatortomanagemultipleoperatingsystemsinVMs.Inthissituation,eachinstanceofanoperatingsystemrunninginavirtualmachinebecomesaself-contained operating environment that runs on top of the hypervisor and behaves as if it is a separatecomputer. VMsarethenmadeupofseveraldifferentcomponents(seeFigure2-9):
▼ Configurationfile Afilethatcontainsthesettingsinformation—amount ofRAM,numberofprocessors,numberandtypeofnetworkinterfacecards (NICs),numberandtypeofvirtualdisks—forthevirtualmachine.Eachtime youcreateanewvirtualmachine,youcreateavirtualmachineconfiguration file,thatis,afilethattellsthevirtualizationsoftwarehowtoallocatephysical resourcesfromthehosttothevirtualmachine.Thisfileindicateswherethe harddiskfileorfilesarelocated,howmuchRAMtouse,howtointeractwith thenetworkadaptercards,andwhichprocessororprocessorstouse.Because itonlycontainssettings,thisfileisusuallysmallandiseitherinpuretextor ExtendedMarkupLanguage(XML)format.
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Figure2-9. ThedifferentfilesincludedinaVMwareVM
■ H arddiskfile(s) Filesthatcontainanyinformationwhichwouldnormally becontainedwithinaphysicalharddisk.Eachtimeyoucreateavirtual machine,thevirtualizationsoftwarewillcreateavirtualharddisk,thatis,a filethatactslikeatypicalsector-baseddisk.Whenyouinstalltheoperating systemonthevirtualmachine,itwillbecontainedinthisfile.Likeaphysical system,eachvirtualmachinecanhaveseveraldiskfiles.Becauseitsimulates aharddisk,thisfileisusuallysignificantinsize,thoughallvirtualization enginessupportautomaticgrowth,lettingthesystemstartwithasmallerfile sizeandscaleitasnewcontentisaddedtothevirtualmachine.Therearetwo maintypes:virtualmachinedisks(VMDK)fromVMwareandvirtualhard disks(VHD)fromMicrosoft.Bothuseaflatfileformatand,likedatabases, willcontinuallygroweachtimeinformationisadded.Onceagain,like databasefiles,virtualdiskdrivefilescanbecompactedtorecoverunused spacewithinthefile. NOTE Virtualharddiskfileswillnotnecessarilygrowasdataisadded;ESXserver,bydefault, leveragesfixed-sizevirtualharddiskfiles,soanew16-GBvirtualdiskwillconsume16GBfromthe beginning.Theonlyexceptiontothisisifyouusethe–thinswitchwhenyoucreateanewVMware virtualdiskfromthecommandline.Oneotherexceptioniswithback-endarraysthatsupportthin provisioning,whereadefaultVMware16-GBvirtualdiskmayonlyconsume4GB,forexample.
■ I n-memoryfile Afilethatcontainsinformationthatisinmemoryforthe runningVMandthatwillbecommittedtotheharddiskfileswhenthevirtual machineisshutdown.
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■ V irtualmachinestatefile Likerealmachines,virtualmachinessupport operationalmodessimilartoStandbyorHibernation.Invirtualizationterms, thismeanspausingorsuspendingaswellassavingthestateofthemachine. Whenamachineissuspended,itssuspendedstateissavedtoafile.Becauseit onlyincludesthemachinestate,thisfileisusuallysmallerthanaharddiskfile.
▲ Otherfile(s) Filesthatcontainlogsandothervirtualmachine-related information.
Thereareotherfileformatsthatsupportthemostadvancedfeaturesvirtualization offers,butthefiletypesdiscussedpreviouslyarethemostcommonforms.Inaddition, eachvirtualizationproductsupports“undoable”disks.Thismeansthattheproductprovidesameanstoreturnthevirtualmachinetoapreviousstatebydiscardingchanges thatmayhavebeenmadetothemachine.Thisisapowerfulfeaturethatisextremely usefulintestinganddevelopmentscenarios,andcanevenbeusefulinproduction.For example,ifavirusinfectsavirtualmachinebutyouhaveaprevioussnapshotofthefiles thatmakeitup,youcanshutdowntheinfectedVMandreturntoapreviouslyuninfectedcopy.Ofcourse,youwouldbecarefulaboutdoingthissinceyoumaylosedata, butitisalevelofflexibilitythatissimplyunavailableonphysicalmachines. Themajoradvantageofthisisthatthephysicaldisksthatnormallymakeupamachine runninganoperatingsystemare“liberated”fromtheirphysicalconstraintsbybeingtransformedintofilesinafolder.Thismeansthatsinceamachineisnowcompletelycontained withinasinglefolder,itbecomesmobileandtransportable.Thesamemachinecanrunon aworkstation,onaserver,onacluster,oreveninaremotelocation.Ifyouwanttoprotect theVM,simplycopythefilesthatmakeituptoanotherlocation.Thisiswhyservervirtualizationtechnologiesaresorevolutionary.Trydoinganyofthiswithaphysicalmachine! Becauseallvirtualmachinesarecomposedofaseriesoffiles,itiseasytoduplicate themandrepurposethematanytime—providing,ofcourse,youhavetheappropriate physicaldiskspace.Also,becausevirtualmachinesarealwaysmadeupofatleasttwo files,itisagoodpracticetoplaceeachmachineintoafolderofitsownonthehosthard disk.Then,ifyouneedtomakeacopy,yousimplycopythewholefolder. Virtualmachinesarealsoeasytobackupandrestore.Becausebackingupinvolves onlycopyingasetoffiles,youcanmakeregularbackupsatcriticalphasesofanyproject.Ifanythinggoeswrong,itiseasytoreturntoapreviousversionofthemachine.No specialbackupagentisrequiredbecauseasfarasthebackuptoolisconcerned,virtual machinesarestoredonafileserver.
ServerVirtualizationModels Asmentionedearlier,therearetwovirtualizationmodelsforSerV(seeFigure2-10).The first,softwarevirtualizationorSoftV,isoftenusedtobeginvirtualizationprojectsbecauseitreliesonsimplerandoftenfreetechnologies,butislessefficientbecauseitrequiresanunderlyinghostoperatingsystem(OS).Thisunderlyinghostoperatingsystem alsorequiresresourcesand,becauseofthis,willimpacttheoperationofthevirtualmachinesrunningontopofit.Forthisreason,organizationswillnotusethismodelunless itisfortestingordevelopment.Becauseitrunsontopofanexistingoperatingsystem,it isoftensimplertorelyonSoftVtolearnhowservervirtualizationtechnologieswork.
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Figure2-10. Thetwodifferentservervirtualizationmodels
However,SoftVshouldneverbeusedinproductionunlessyouhavelowservice level agreements and you can afford to have the services made available within the virtualmachinestakenofflineforlongerperiodsoftimewithoutnegativelyimpacting users. Few organizations have this level of flexibility with their networked services. Inaddition,runningavirtualizationproductontopofanexistingOSmakesallofthe virtualmachinessubjecttotheupdateprocessforthehostOS.Ifrebootsarerequired, alloftheVMswillberebootedaswell.Notthebestofscenarios. Forthisreason,youmustusethesecondmodelwhenyoumovetoproduction,the hardwarevirtualizationlayer,orHardV.Inthiscase,thehypervisorcodewillbeintegrateddirectlyintothehardwareandwillsimplyexposethehostserver’shardwareto theVMsthatarerunningontopofitandtakeverylittleawayfromthephysicalresources ofthehost,lettingasmanyvirtualmachinesaspossiblerunonit.Inaddition,sincethe hostdoesnotactuallyincludeanormalOS,itdoesnotrequirepatching,oratleastdoes notrequirepatchingandupdatesatthesamerateastheoperatingsystemsrunningin theVMs.Thisminimizestheimpactthehypervisorhasonthemachinesithosts.Because ofthis,HardVis,byfar,thebestmodeltouseforseriousservervirtualization. Forexample,VMwareESXiisa32-megabyte(MB)hypervisorthatdoesnotrequire anOSandcanrundirectlyfromfirmwareoraninternaluniversalserialbus(USB)key. VMwareisnottheonlyvendorthatoffersahypervisorthatisintegratedwiththehost serverhardware.ThislevelofintegrationgivesyoutheopportunitytocreateanewdisklesshostservermodelusingnothingbutRAM,processor,andnetworkresourcestohost virtualmachines. NOTE VMwareESXiisalsoafreetechnology.Youcandownloadafullyfunctionalversionfrom www.vmware.com/go/getesxi.Microsoftalsooffersafreeversionofitshypervisor,WindowsHyper-V Server,butithaslimitedfunctionalityanddoesnotprovideallofthefeaturesyouobtainfromthe version found in the Windows Server 2008 code.You can download it from www.microsoft.com/ windowsserver2008/en/us/hyperv.aspx. Server virtualization is still the most popular of the different virtualization technologies,andrightlyso.Justthinkofallofthethousandsofserverstodayrunningat lessthan10percentutilization—andthatisgenerous,asmanyarerunningatlessthan
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5percentutilization.Eachoftheseserversisdrawingafullamountofpower,requiring afullamountofcooling,andrequiringafullamountofspaceindatacentersaround theworld.Thenimaginethatwhenproperlyconfiguredtoruninservervirtualization, thesamephysicalservercanactuallyrunmorethantenvirtualmachines,servers,or desktops.Eachofthesevirtualmachinesdoesnotrequireitsownpower,eachdoesnot generateitsownheat,andeachdoesnotrequirespace,yeteachofthesevirtualized machinescanofferupthesameservicesitdidwhilerunningonaphysicalmachine. Isn’tthatworthlookingintoifyou’renotusingthistechnologyrightnow? Eachvirtualmachineisnothingmorethanasetoffilesonadisksomewhere.When youtakeaphysicalinstanceofaserverandconvertittoavirtualinstance—effectively performingaP2Vconversion—youtransformthephysicalmachineintoasetoffilesin afolder.Thenonceitisinthisstate,youcanmoveitfromservertoserver,shutitdown, rebootit,hibernateit,andbasicallydoanythingwithitthatyoucouldbeforewithout anysignificantperformancedegradation.
MajorServerVirtualizationVendors GuestOSvirtualizationvendorsabound,butthreemainvendorshavetakenthemarket bystorm:
▼ C itrixoffersahostofdifferentvirtualizationtechnologies(www.citrix.com/ xenserver)andisaimingtoexpanditsofferingsintoallofthevirtualization realms.XenServercomesinfourflavors.ExpressEditionisafreestarter versionoftheproduct.StandardEditionisthebasicversion,whichsupports twoVSOsatonce.Enterpriseaddstheabilitytopoolhardwareresourcesand rununlimitedVSOs.PlatinumEditionaddsdynamicprovisioningofboth hostsandVSOs.Citrixoffersanoriginalequipmentmanufacturer(OEM) versionoftheirhypervisor,whichcomesbuiltintoserverhardware.Citrix alsooffersXenDesktopforDeskVandXenAppsforAppV.
■ M icrosoftoffersahostofvirtualizationtechnologiesineachofthevirtualization realms,withadditionalproductsinthepipeline(www.microsoft.com/ virtualization).MicrosoftcurrentlyoffersVirtualServer2005R2SP1and VirtualPC2007,whicharebothfreebutareSoftVproducts.Itsenterprise-class hypervisor,Hyper-V,ispartoftheWindowsServer2008OSandwillonlyrunon x64hardware.MicrosoftalsooffersMicrosoftApplicationVirtualizationforAppV, TerminalServicesforPresentV,andhasmadesomeacquisitionstogetintoDeskV.
▲ V Mwareoffersthemostmatureproducts,withafullrangeofserverand desktopvirtualizationtools(www.vmware.com).ItoffersVMwareServer,which isanotherfreeSoftVproduct;VMwareWorkstation;andVirtualInfrastructure, whichisacompleteplatformbasedonitsESXServerhypervisor.VMwarewas thefirsttoofferahypervisorbakedintotheserverhardwarewithESXiandto makeitafreeadd-ontoahostserver.VMwarealsoofferstheVirtualDesktop Infrastructure(VDI)forDeskVandThinAppforAppV.
Runninganyofthesevendorproductswillletyouvirtualizeanyenvironment,whether itistraining,testing,development,orevenproduction.Andwhat’sevenbetteristhat
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eachofthesevendorsoffersafreeversionoftheirtoolstoletyoubeginyourvirtualizationprojectwithouthavingtobreakthebank. NOTE MicrosoftHyper-VwillrunonanysystemthatisabletorunWindowsServer.Thismeansit willrunonthousandsofserverconfigurations.LookuptheWindowsHardwareCompatibilityListfor moreinformationatwww.microsoft.com/whdc/hcl/default.mspx.VMwareESXandCitrixXenServer will run on select configurations only. For information on the systems supported forVMware, look up theVMware Systems Compatibility Guide for ESX Server 3.5 and 3i at www.vmware.com/pdf/ vi35_systems_guide.pdf,andtheI/OCompatibilityGuideforESXServer3.5and3iatwww.vmware .com/pdf/vi35_io_guide.pdf.ForsystemconfigurationsforCitrixXenServer,lookuptheXenServer Compatibilitylistatwww.citrix.com/English/ps2/products/feature.asp?contentID=1453254. Oracle (Oracle VM), Novell (Xen), Red Hat (Xen), IBM, Sun (xVM), Virtual Iron, andothersalsoalloffertheirownhypervisors,whichcanandwillbecomeconfusing ifyou’retryingtofigureoutwhichtooltouse.Keeptothethreemainvendorsifatall possible.Itmaynotbepossible,assomevendorswillnotsupporttheirapplicationsif theyarerunninginacompetitor’shypervisor.Forexample,Oraclewillonlysupportits applicationsiftheyrunonOracleVM(www.oracle.com/technologies/virtualization/ docs/ovm-faq.pdf).Microsoft,however,hasa“besteffort”supportpolicyfortheirproductsrunninginanyversionofahypervisor,whetheritistheirsornot(seeKnowledge BaseArticlenumber897615athttp://support.microsoft.com/kb/897615). Keep this in mind when you choose your virtualization platform and management products.Managementproducts,especially,shouldbehypervisor-agnostictoensurethat youcancontinuetomanageyourinfrastructureifyoudoenduprunningmorethanone hypervisor.Table2-1outlinesthevariousproductsavailablefromdifferentmanufacturers.
VendorProduct
Description
CitrixXenExpressEdition www.citrix.com/ English/ps2/products/ subfeature.asp?contentID=683152
Afreeeditionthatisaproductionreadyvirtualizationplatformand supportsdualsocketserverswith upto4GBofRAM.XenExpresscan hostuptofourvirtualmachineson eachsystemandcanbeupgradedto StandardorEnterpriseEdition.
CitrixXenServerStandardEdition www.citrix.com/ English/ps2/products/ subfeature.asp?contentID=683151
XenServerisavirtualizationplatform forWindowsandLinuxguest operatingsystems,andisanative 64-bitXenhypervisor.XenCenter administratorconsolesupports multiservermanagement.
Table2-1. MajorVirtualizationSolutions(continued)
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VendorProduct
Description
CitrixXenServerEnterpriseEditionorOEM www.citrix.com/English/ps2/ products/subfeature.asp?contentID=683150
Inadditiontothebasefeaturesof theStandardEdition,theEnterprise EditionoffersXenMotionLive Migrationandtheabilitytomanage hardwareresourcepools.
CitrixXenServerPlatinumEdition www.citrix.com/English/ps2/ products/subfeature.asp?contentID=1297952
Inadditiontothebasefeaturesof theEnterpriseEdition,thePlatinum Editionletsyouunifyvirtualand physicalserverprovisioning.
CitrixXenDesktop www.citrix.com/ English/ps2/products/ product.asp?contentID=163057
XenDesktopincludesseveraleditions aswell.TheExpressEditionisfreeand supportsuptotenusers.TheStandard Editionisanentry-leveldesktop virtualizationplatform.TheAdvanced Editionsupportsvirtualdesktops butdoesnotincludeapplication delivery.TheEnterpriseEditionadds virtualapplicationdelivery.Andthe PlatinumEditionoffersanend-toenddesktopdeliverysolutionwith virtualapplicationdelivery,complete performancemonitoring,andQuality ofService(QoS)capabilities,aswellas remotevirtualdesktopsupport.
MicrosoftVirtualServer2005Release2Service Pack1EnterpriseEdition http://technet2.microsoft.com/ windowsserver/en/library/ bcc5e200-88af-4a64-963b-55f1efb251d11033 .mspx?mfr=true
MicrosoftVirtualServerisafreetool availableinboth32-bitand64-bit versions;however,itonlysupports 32-bitvirtualmachines.
MicrosoftVirtualPC2007 www.microsoft.com/ windows/products/winfamily/ virtualpc/overview.mspx? wt_svl=20323a&mg_id=20323b
VirtualPCisalsoafreetoolthatcan runmultiplePC-basedoperating systemssimultaneouslyonone workstation.
WindowsServer2008Hyper-V http://technet2.microsoft.com/ windowsserver2008/en/library/ c513e254-adf1-400e-8fcb-c1aec8a029311033 .mspx?mfr=true
Hyper-Visanintegratedserverrole withinWindowsServer2008.Itisa native64-bithypervisorthatcanrun 32-bitand64-bitVMsconcurrently.
Table2-1. MajorVirtualizationSolutions(continued)
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VendorProduct
Description
VMwareServerVirtualization www.vmware.com/products
VMwareoffersseveralversionsof itsvirtualizationproducts.VMware ServerisafreeSoftVproduct. VMwareESX3iisafreehardwareintegratedhypervisor.VMware ESXServercanalsobeinstalledon non-hardware–integratedsystems. VMwareVirtualInfrastructureis acomprehensivesetoftoolsfor virtualizationmanagementand deployment,andcomesinseveral differenteditions.
VMwareDesktopVirtualizationTools www.vmware.com/products
VirtualDesktopInfrastructure (VDI)isdesignedtohostdesktop environmentsinsideVMsrunningin thedatacenter.VMwareThinAppisan AppVsolutionthatsupportsalmost anyapplication.VMwareWorkstation isaflagshipdesktopvirtualization toolthatcanrunthewidestvarietyof operatingsystems.VMwareFusion isanotherdesktopvirtualization tool,butisdesignedtorunonthe Macintosh.
Table2-1. MajorVirtualizationSolutions(continued)
Thereareseveralbenefitstoservervirtualization:
▼ T hefirstoneiscertainlyatthedeploymentlevel.Avirtualmachinecanoften bebuiltandcustomizedinlessthan20minutes.Youcandeliveravirtual machinethatisreadytoworkrightawayinconsiderablylesstimethanwith aphysicalmachine.ButyouwillhavetobecarefulnottointroduceVM proliferationintoyourinfrastructure.Youneedtocontinuetocontrolmachine requests,whethertheyarephysicalorvirtual.Youdon’twanttoendupwitha wholeseriesofvirtualmachinesjustbecauseyoucancreatethemeasily.
■ A notherbenefitisvirtualmachinemobility.YoucanmoveaVMfromonehost toanotheratanytime.Insomecases,youcanmoveitwhileitisrunning.This isagreatadvantageandwillhelpreducedowntimeinyournetwork.
■ V irtualmachinesarejusteasytouse.Onceitisbuiltandconfigured,youjust startthemachineanditisimmediatelyreadytodeliverservicestousers.
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■ V irtualmachinessupportstandardconfigurations.Youcancontroltheway VMsarebuilt:JustcreateastandardVMandcopythesourcefilesforthisVM eachtimeyouneedanewmachine.Thisway,youwillalwayshavestandard configurationsforanyVM.
■ V irtualmachinesalsosupporttheconceptofvolatileservices.Ifatesteror developerneedsavirtualmachinetoperformagivenseriesoftests,youcanfireup anewVM,provideittotheminminutes,andthen,whentheyaredonewithit,you simplydeleteit.Trydoingthatwithaphysicalmachine!
■ V Mscanbecertifiedbythevirtualizationvendor,ensuringyouareusingthe bestoftheirtechnology’scapabilitieswithyourVMs.
■ V Msarealsosecurebecausetheycanbecompletelyisolatedatanytime;just cutofftheircommunicationsthroughthehost’svirtualizationtechnology.
■ V Mscanbescaledoutorscaledup.Toscaleout,simplycreatemoreVMswith thesameservices.Toscaleup,shutdowntheVMandassignmoreresources, suchasRAM,processorcores,disks,andNICstoit.
▲ V Msarealsoidealfordisasterrecovery,sinceallyouneedtodoiscopytheir filestoanotherlocation,eitherwithinyourdatacenterortoanothersiteentirely.
Becauseofthesecorebenefits,itisdifficulttoimaginewhyanyonewouldnotwantto useservervirtualization.Servervirtualizationletsyoumapcomputingresourcestobusinessrequirementsinaone-to-onerelationship.ItallowsyoutolowerITcoststhrough increasedefficiencyandresourceallocation.Youcanprovisiontheresourcesyourequire onanas-neededbasis.Virtualizationletsyoutreatyourdatacenterasasinglepoolof resources,blendingserverhardwarewithalloftheotherhardwareinthedatacenter(see Figure2-11).Withservervirtualization,youcanturnallend-userserviceofferingsinto virtualworkloadsandturnallhardwareresourcesintoresourcepools,creatinganew datacenter,onethatdividesallworkloadsintovirtualandphysicalrepresentations.
Figure2-11. Workingwithresourceandvirtuallayersinthedatacenter
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DesktopVirtualization The same technology that powers server virtualization can also power desktop virtualization.Desktopvirtualizationcentralizesdesktopdeploymentssothatyoucangain completecontroloverthem,lettingusersrelyonavarietyofendpoints—thincomputing devices,unmanagedPCs,homePCs,orpublicPCs—toaccessyourcorporatedesktop infrastructure,onceagainthroughtheRemoteDesktopConnection(RDC).ThemaindifferencebetweenDeskVandPresentV,orpresentationvirtualization,oftencalledTerminalServicesorserver-basedcomputing,isthatinPresentV,usersmustsharethedesktop environmentwithalloftheotherusersconnectingtotheserver.InDeskV,eachusergets accesstotheirowndesktop,limitingthepotentialimpactoftheapplicationstheyneed onotherdesktopsessions.Bycontainingapplicationswithinvirtualdesktops,youcan guaranteethatifsomethinguntowardoccursinonevirtualdesktop,itwillnotaffectany oftheothersrunningonthesameserver. Justthinkofwhatyoucandowithvirtualizeddesktopsbyplacingtheminvirtual instancesonaserverandgivingusersremoteaccesstotheenclosedandcontrolledenvironmentavirtualdesktopprovides.Asadministrators,youcanusethemtotestpatch andservicepackdeployment,providesupportinmultisystemenvironments,provide trainingtoendusersandtechniciansalike,orsimplyprovidecontrolledenvironments. Whenyourtestortrainingisdone,justresetthevirtualmachinebacktoitsoriginalstate andyou’rebackinbusiness.DeskVcanbequiteatime-savercomparedtothecostof managingdistributedsystemsthroughoutyourinfrastructure.Ifyouhaveexistingdesktops,youcanturnthemintounmanageddevicesbecauseallyouneedfromthephysical workstationarethreethings:
▼ A baseoperatingsystem,whichcanbeanythingfromWindowsXPtoVistaor beyond.Thisbaseoperatingsystemmustbepatchedandupdated,whichis somethingyoumustdoanyway.
■ P ropervirusprotection,anotheritemyoumustmanageanywayifyouhave physicaldesktops.
▲ ARemoteDesktopConnectionclient.
That’sit.Youdon’tneedadditionalapplicationsoranyotheroverheadonthesystem. Managingtheseendpointsismuchmorecost-effectivethanwhenyouhavetodeploy andupdatehundredsofapplicationsonthem. Ifyourorganizationcanaffordit,transformallofyourphysicaldesktopsintothinclients.Thinclientsupdatethemselves,don’treallyhaveanyinternalsoftware,andaremuch easiertomanagethanactualdesktops.Eachsingledesktopsystemyouremovefromyour environmentwillreduceyourpowerconsumptionby650,000kilowatt-hoursperyear. Thereareseveralotherreasonsformovingtovirtualdesktops.Hereareafew:
▼ Y oucancreateenterprise-standardlock-downPCsonunmanagedremote PCs.Bycentralizingthedesktopthroughservervirtualization,youcanlock downthecorporatePCimagewhilelettingusersrunfreeontheunmanaged physicaldesktops.Thisgivesyoustandard,centralizedconfigurationsand usersarestillhappybecausetheycandowhatevertheyfeeltheyneedtoon theunmanagedPC.
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■ Y oucancreatetime-controlledPCimages.Ifyourorganizationisinthehabit ofhiringtemporaryorseasonalemployees,youcangeneratetime-controlled virtualPCimages,whichwilldisappearoncetheneedforthemisover. TemporaryemployeescanevenworkfromhomeusingtheirownPCs,since alltheyneedtoaccessyourcorporateimageisanRDCclient,whichispartof everyWindowsinstallationbydefault.
■ Y oucanalsosecureinformationbykeepingdesktopsinthedatacenter.By controllinghowremoteconnectionsareenabledforthevirtualPC,youcan ensurethatanydatageneratedthroughthePCimageiskeptwithinthe datacenterandcannotleavethepremises.Thisgivesyoucompletecontrolover corporateintellectualproperty.
■ Y oucanencapsulatecomplexorsensitiveapplications,isolatingthemfrom anyothers.Forexample,employeesthatmustuseseveraldifferentlevelsof securitytoaccesscorporatedataoftenhadtouseseveraldifferentphysicalPCs toproperlyaccessthisdata.Now,youcanprovidethemwithseveraldifferent virtualPCimages,eachconfiguredtosupporttheappropriatelevelofsecurity.
■ D eskVcanprovideanewmigrationpathtonewoperatingsystems.Many peopledonotmovetoneweroperatingsystemssuchasVistabecausetheymust upgradealloftheirendpointstodoso,butwhenyourunthenewOSinavirtual environment,noendpointsneedchangesincetheyonlyrequireanRDCclientto accesstheupdateddesktops.Thisgreatlyfacilitatesdesktopmigrations.
▲ D eskVisalsoagreatmodelfortestinganddevelopmentsincelikeany servervirtualizationmachine,theysupportundoabledisksandcaneasilybe spawnedwhenneeded.
Tomovetoacentralizeddesktopenvironment,allyouneedtodoisgenerateacore virtualimageandthenspawnallotherimagesfromthisfirstandstandardconfiguration.Fromthenon,userscanrelyonanyendpointtoaccesstheirownpersonalvirtual PCimage,eventhroughthefirewall(seeFigure2-12).
ApplicationVirtualization Thelastkeyvirtualizationlayerthatmostcloselyresemblesservervirtualizationisapplicationvirtualization.Applicationvirtualization,orAppV,createssoftwareorservice isolationontopoftheOSthroughaspecialvirtualizationlayer.Inthisregard,AppV most closely resembles software server virtualization, or SoftV, because it requires an underlyingoperatingsystemtofunction.TheadvantageAppVoffers,however,isthatit completelyprotectstheOSfromanychangesapplicationscanmakeduringinstallation. That’sbecausewhenyouprepareanapplicationforAppV,youdon’tcapturetheinstallationprocessasorganizationsdidtraditionally;instead,youcapturetherunningstate oftheapplicationorwhateverisrequiredtomaketheapplicationfunctionalonanOS. Becauseofthis,AppV-enabledapplicationscansimplybeXcopiedtoendpointssince noinstallationisrequired.Thisprovidesapowerfulmodelfordistributedapplication management.AppValsoprovidessupportforapplicationconsolidation.
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Figure2-12. RelyingonDeskVletsyoumaintainstandardcentralimages,whichuserscanaccess fromanyendpoint.
ThereareseveralvendorsolutionsforAppV:
▼ Applicationvirtualizationthroughstreamingtechnologies:
■ M icrosoftApplicationVirtualization(MAV,formerlySoftGrid)allows youtodeliverapplicationsthatareneverinstalledandaredynamically deliveredondemand.MAVcanbedeployedondesktops,laptops,or terminalservers.MAVisacorecomponentoftheDesktopOptimization PackforSoftwareAssurance.Formoreinformation,seehttp://technet .microsoft.com/en-us/appvirtualization/default.aspx.
■ C itrixXenApp(formerlyCitrixPresentationServer)isanend-to-end Windowsapplicationdeliverysystemthatoffersclient-sideandserver-side applicationvirtualization,aswellaspresentationvirtualization.For moreinformation,seewww.citrix.com/english/ps2/products/product .asp?contentid=186.
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■ S ymantecSoftwareVirtualizationSolutionPro(SVS)isanapplication virtualizationplatformthatworksthroughlocalsystemfilters.ThePro EditionincludesastreamingcomponentformerlycalledAppstreamand providesperhapsthemostadvancedstreamingplatformonthemarket. Formoreinformation,seewww.symantec.com/business/products/ overview.jsp?pcid=pcat_infrastruct_op&pvid=sv_sol_pro_1. ▲ Agentlessapplicationvirtualization:
■ V MwareThinApp(formerlyThinstall)encapsulatesapplicationsfromthe OSandeachother,eliminatingcostlyregressiontestingandconflictsfrom badlybehavingapplications.Justpluginan.msior.exefiletodeploy avirtualsystemenvironment,includingregistrykeys,DynamicLink Libraries(DLLs),third-partylibraries,andframeworks,withoutrequiring anyinstallationofagentsorapplicationsontheunderlyingoperating system.Formoreinformation,seewww.vmware.com/products/thinapp/ ?hl=en&rlz=&q=thinapp&meta.
■ I nstallFreeBridgeprovidesaclientlessplatformthatcreatesatransparent “bridge”betweenvirtualapplicationsandtheOS,protectingtheOSfrom anyapplicationchanges.Formoreinformation,seewww.installfree.com/ pageload.aspx?page=products_bridge.html.
As you can see, two vendors, VMware and InstallFree, offer solutions that do not require the prior deployment of an agent on the target desktop. This truly liberates applicationsfromanytiesorbindsandmakesthemcompletelytransportable.Whether youoptforanagentlessoranagent-basedAppVsolutionwilldependonyourneeds, butinmostcases,agentdeploymentisrarelyanissueandprovidesabettermeasureof controlovervirtualapplicationsthanagentlesssolutions—noagent,noapplication;it’s assimpleasthat. There are several advantages in virtualizing applications. Traditional application installationspenetratetheoperatingsystemandchangeitsconfiguration.Eventually, managedorunmanagedsystemsbecomecompletelytransformedandunrecognizable. For this reason, many organizations continually reimage their desktops over time to resetthemtoaknownconfiguration.Instead,applicationvirtualizationprotectstheoperatingsystemfromanymodificationsandsupportscompletelysecureenvironments (seeFigure2-13). And, most importantly, any application that has been virtualized can run on any versionofWindows.That’sbecausetheAppVlayermanagesallinteractionsbetween avirtualapplicationandWindows.Onceanapplicationhasbeenvirtualized,itnolongerneedstoberepackagedeachtimeyouneedtochangetheOS.Forthisreasonalone, AppVisoneofthemostpowerfulnewtechnologiesITcanadopt. As you can see, virtualization has a significant impact on servers, desktops, and applications.Fortheservers,virtualizationsupportshardwareconsolidation,increases thegreenfootprintoftheservers,andprovidesthebestmodelforbusinesscontinuity. For the desktops, virtualization supports desktop centralization, information protection, and can provide a secure desktop environment. Finally, virtualization provides
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Chapter 2:
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Figure2-13. RelyingonAppVtoprotectthetargetOS
theonlymodelorganizationsshouldusefordistributedsystemmanagementofapplications.Thechallengefororganizationsisknowinghowtobringthesethreelayersof virtualizationtogetherinacoherentimplementationinordertomakethemostofeach technology.
WORKWITHTHEFIRSTTWOSTEPS ThefirsttwostepsoftheResolutionsFive-StepProcessfocusonthediscoveryofnew technologiesandhowtheycanhelpyourorganizationmovetowardsawholenewdatacenter.VirtualizationtechnologiesofferanewparadigmforITinthedatacenter,turning thestaticenvironmentswehaveworkedwithinthepastintodynamicenvironments thatcanofferservicesondemand.However,thistransformationdoesnotoccuronits own;itmustbetemperedwithnewwaysofdoingthings.Thisiswhatthenextthree stepswillhelpprovide.
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hapter2begantheResolutionsFive-StepProcess.Whilethefirsttwostepswere focusedonthediscoveryofbothwhatisinyournetworkandwhatvirtualization actuallyis,theremainderofthefivestepsfocusonhowyouneedtoadaptyour environmenttomakeitallwork.Stepthreeoutlineshowyourviewofhardwareneeds to change. Step four looks at how each of the layers—hardware and software—work togethertoformacohesivearchitecture.Andstepfivelooksathowyourmanagement needstochangetoadapttothedynamicdatacenter.
STEP3:HARDWAREMAXIMIZATION Nowthatyouunderstandthedifferentlevelsatwhichyoucanapplyvirtualization,you can begin to think of how virtualization technologies, especially server virtualization, willchangethehardwareyourunyourworkloadson.Thedatacentersofmostorganizationshaveevolvedintoserverroomsrepletewithsmall,single-purposeserversrunning fromdirect-attachedstorage.Whilethisworksinaworldrichwithresourcesandwhere nooneneedstoworryaboutspace,itnolongerworksinthedynamicdatacenter. Whenyoumoveyourserversanddesktopstovirtualworkloads,youmustconsider changingthenatureofthehardwareyourelyontoensurethatthesystemsyourunyour virtualworkloadsonarealwayshighlyavailable.Inaddition,sincethetransformation ofthedatacenterreliesonmovinglow-useworkloadsontofewerhardwaresystems,it isimportanttomakesurethateachofthesystemsyourunoffersthewidestamountof resourcestotheseworkloads.Forthisreason,youmustrethinkthedatacenterandmost likelytransformitintoaleanerandmeanerresourcepool.
Moveto64-Bit Sinceyourhardwareserversarenowgoingtorunmultiplevirtualworkloads,youmust considerhardwarethatcandeliverthebestprice/performance.Oneofthefirstplaces tostartiswithpotentialbottlenecks.Oneofthemostimportantbottlenecksisrandom accessmemory(RAM).Sinceeachvirtualmachinemustaddressitsownmemory,your serverconfigurationsmustbedesignedwiththeutmostinmemoryconfigurations.In addition,thesystemmustusethebestresourcestomakethismemoryavailabletoeach virtual machine. For this reason, it is important to consider 64-bit processor architectures. Inthiscase,youmustlooktox64processors,notItaniumorIA64.x64processorsare anextensionof32-bitx86architecturesand,becauseofthis,canrunmuchofthesame codex86systemscan.But,becausethex64architectureisa64-bitarchitecture,itcanaddressalotmorememorythanx86systemscan.Memoryhasalwaysbeentheproblem withcomputingsystems.Manyyearsago,AppleChairmanSteveJobswasquotedas sayingthat“developerswouldjusthavetolearntoprogramtightly”whenreferringto thememorylimitationsoftheoriginalMacintosh,whichwasshippedwithonly128kilobytes(KB)ofRAM.ItonlytookAppleeightmonthsbeforetheyproducedtheFatMac, aversionrunningwithafull512KBofRAM.Therestishistory.
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Computershavealwaysneededaccesstoalotofmemory.Infact,memoryhasbeen toutedasthesinglemostsignificantlimitationforapplicationoperation.We’realong wayfromthekilobytesoftheoriginalMacintoshesorIBMPCs,butevenwhencomputersarerunningwithtrue32-bitprocessorarchitecturesandthecorrespondingoperating systems,itispossibletorunintomemorybottlenecks.That’sbecausethe32-bitprocessorisdesignedtoaddressnomorethan4gigabytes(GB)ofRAM(seeFigure3-1). In default configurations, the base 4GB of a 32-bit system is divided into two sections. The first 2GB is reserved for kernel processes. This space is allocated to the coreoperatingsystem(OS).Thesecond2GBofRAMisassignedtoapplicationvirtual memory.Thisisthespacewhereapplicationscanexecute.Stopgapmeasurescanchange theseconfigurations.Forexample,ifyouassignthe/3GBswitchtothebootprocess,the kernelprocessspacewillbereducedto1GBand3GBwillbereservedforapplications. Inthissituation,applicationshaveaccesstomorephysicalmemory,butthenthecoreOS becomesabottleneckbecauseitcannotaddressitsfullcomplementofmemory.Youcan alsousethePhysicalAddressExtension,or/PAEswitch,atstartup.Thischangesthe memorymanagementspacefrom32to36bitsandallowstheoperatingsystemtoswap applicationmemoryintotheAddressWindowingExtensions,providingmorephysical memory to the system beyond the base 4GB. But when applications need to execute code,theymustbeswappedbackintothebase2GBofapplicationvirtualmemory(see Figure3-2).Thismeansthatevenifasystem“sees”morethan4GBofRAM,applications arestillbottleneckedbyhavingtofitintothebase2GBtoexecute. Theonlywaytomovebeyondtheselimitationsandaccessmorememorywhilestill executingthesameapplicationcodeisthroughx64processorarchitectures.Bydefault, x64processorarchitecturescanaddressmorememory,muchmorememorythantheir x86counterparts.Themaximumamountofphysicalmemorythatwillbeaccessibleto yourapplicationsdependsontheoperatingsystemyouchoosetorun.Table3-1outlines thevariousmemorylimitsavailablebasedontheversionofWindowsyourunonyour x64machine.
Figure3-1. Possiblememoryconfigurationsin32-bitprocessorarchitectures
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WindowsVersion
PhysicalMemorySupport
WindowsXPProfessionalx64
128GB
WindowsServer2003Standardx64Edition
32GB
WindowsServer2003Enterprisex64Edition
2terabytes(TB)
WindowsServer2003Datacenterx64Edition
2TB
WindowsVistaHomeBasicx64
8GB
WindowsVistaHomePremiumx64
16GB
WindowsVistaBusiness,Enterpriseor Ultimatex64
128+GB
WindowsServer2008WeborStandard x64Edition
32GB
WindowsServer2008Enterprisex64Edition
2TB
WindowsServer2008Datacenterx64Edition
2TB
Table3-1. MemorySupportforWindowsx64Editions
Figure3-2. Usingthe/PAEswitchletstheOSswapapplicationsintoandoutofthebase2GB availableforapplications.
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Forexample,ifyouarerunningthex64WeborStandardEditionofWindowsServer 2008,yoursystemswillbeabletoaccessupto32GBofphysicalRAM.Ifyouarerunning thex64EnterpriseorDatacenterEdition,yoursystemswillbeabletoaccessupto2TB ofRAM.Thatissignificantlymorethanwhatisavailableona32-bitsystem.Inaddition, eachOScanaccessmorethan16TBofvirtualmemory.Ofcourse,noonehasaserver configurationthatisavailablewithsupportfor2TBofRAMoraworkstationconfigurationwithaccessto128GBofRAM,buttheycan’tbethatfaraway. ForWindowsServer2003systemstoaccessthefullRAMcapabilitiesofthex64platform, they must be running Service Pack 2 or later. In addition, Microsoft claims the x64versionsofVistaUltimate,Enterprise,andBusinessEditionscanultimatelyaccess morethan128GBofRAM,buttheMicrosoftDeveloperNetworkWebsiteclaimsthat applicationswillonlyhaveaccessto128GBevenifmorecanbefoundonthesystem hardware. One thing is sure: Each and every Windows or Linux OS based on x64 code can accessmorememorybydefaultthananyx86or32-bitOS.AccessingthismuchRAM meansapplicationscannowfullyexecuteasintended.Microsoft’sWindowsServeroperatingsystemscanassignafull8TBofvirtualmemorytoanyapplication.Andapplicationsdon’thavetobewritteninnativex64codetotakeadvantageofthischange;even 32-bitapplicationswillseeaperformancegainwhenrunningonanx64OSbecausefor thefirsttimeintheirhistory,theseapplicationscangainaccesstoafull4GBofRAM withouthavingtosharethebasememoryblockswiththeOS.Nomoreswitchesarerequired,andapplicationperformanceimprovesineverysingleinstance.Theapplication, however,mustbeabletosupportthe/LARGEADDRESSAWAREoptionwithinitscode toprofitfromthefull4GBofRAM. Ifyouwanttoremovethesinglemostconstrictingbottleneckfromyoursystems, look to x64 operating systems. Few vendors, if any, now sell x86 processors, and all organizations who own them should be running x64 operating systems on x64 hardware,eventhoughthex86OSiscompatible.Bestofall,youdon’tevenneedto changeyourapplicationstoaccessthisfeature.Everyx86applicationisx64-compatiblebydefault. Inaddition,thecurrentpriceof32-and64-bitserver-classmachinesisnearlyidentical.BothAMDandIntelofferx64processors.Manyhypervisorsarealso64-bit–only hypervisors.Whilenotallhypervisorsare64-bit,allofthematleastuse64-bitmemory managers.Thisisonemorereasonwhy64-bithardwareisamust.Ifyou’regoingto takethetimetomovetoavirtualinfrastructure,youshouldmakesurethatthesystems youusetohostvirtualworkloadsarethebestandarereadytoperformthistaskforthe longterm.
RelyonSharedStorage Inadditiontoremovingresourcebottlenecksinyourserverconfigurations,youmust removepotentialsinglepointsoffailure.Whenyouplace10,20,oreven30virtualmachines on a single host server, you must make sure that there is no way for this host server to fail; otherwise, all of the virtual workloads will also fail, causing some irate endusers.Forthisreason,youmustconfigurehardwarewithhighavailabilityinmind.
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Inmostcases,thismeansusingsomeformofclustering.WhilevendorslikeMicrosoft andCitrixactuallyrelyonclusteringservicestoprotectthevirtualworkloadsrunning ontheirsystems,VMwareusesacustomconfigurationcalledHighAvailability(HA). In the end, each configuration is the same: Several computer nodes are linked togethertoprotecttheworkloadstheyrun.Shouldonemachinefail,theworkloadsare automaticallytransferredtoanotheravailablenode. Whatmakestheseconfigurationsworkissharedstorage.Eachnodeislinkedtothe samestoragecontainer.Thismeansthatwhenaworkloadneedstofailover,thefilesthat makeitupdonotneedtobemovedorcopiedtothenextavailablecomputernode.In addition,virtualizationtechnologiessupporttheabilitytodynamicallymoveworkloads fromonesystemtoanotherwhenthevirtualworkloadneedsmoreresourcesthanare currentlyavailableonthenodeitresidesonatthetime.Theworkloadisautomatically movedtoanothernodethathasavailableresourceswithoutadministrativeinteraction. Once again, this can only be made possible when the virtual workload is located on sharedstorageofsomesort.Thisiswhythebestwaytostorevirtualmachinesistorely onsharedstorage(seeFigure3-3).Youcanstoreallvirtualmachinesonasharedstorage subsystem.Inaddition,becausethesystemsattachedtoasharedstorageinfrastructure arelocatedinthesamesite,theyareconsideredtoprovidesite-levelredundancy.And, sincethevirtualmachineisthepointoffailure,everyapplicationyouruninsideofthem isautomaticallyhighlyavailable. Becarefulthatyoursharedstoragesubsystemdoesnotbecomeasinglepointoffailureofitsown.Alwaysthinkredundancywhenplanningforhardwarecomponentsthat willsupportvirtualworkloads.
Figure3-3. Usingsharedstorageallowsyoutocreatehighlyavailableconfigurations.
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BeAwareofLicensingCosts The monetary savings of virtualization are incredible and make for an easy business case. First, you save on all of the hardware you no longer need to buy. Second, softwaremanufacturerssuchasMicrosofthavechangedtheirsoftwarelicensingmodelsto supportvirtualizationeversincethereleaseofWindowsServer2003R2(WS03R2)and continuingonwithWindowsServer2008(WS08).BuyingalicenseofWindowsServer 2003R2orWindowsServer2008EnterpriseEditionnowgrantsyouuptofourfreevirtualinstancesoftheOS,aswellasprovidingalicenseforthehostserverifyouchoose torunWindowsServeronit.Eachadditionallicensegivesyouuptofourmoreguests. BuyingalicenseofWindowsServer2003R2orWindowsServer2008DatacenterEdition givesyoutherighttorunanunlimitednumberofvirtualizedinstancesofanyWindows ServerOS.Table3-2outlinessomeofthesavingsinvolvedinvirtualization.Ofcourse,if yourunLinuxworkloads,thelicensingissuemightbemoot. Tohelpyoudiscoverthebenefitsofvirtualizationanditsimpactonoperatingsystem licensing, Microsoft has developed a Virtualization Calculator, which can be found at www.microsoft.com/windowsserver2003/howtobuy/licensing/calculator.mspx. The two calculators provide two ways to estimate the number and cost of Windows ServerStandard,Enterprise,orDatacenterlicensesforvirtualizationscenarios.Thefirst calculatorisdesignedtoestimatethelicensesandcostofWindowsServerbyedition,as wellasnumerousMicrosoftServerproductsonasingle,physicalserver(seeFigure3-4). The second calculator helps you estimate the licenses and costs of only the Windows
Category
PotentialSaving
Hardware
Eachserverordesktopyoudonotpurchaseputsmoney inyourpocket.
OSLicensing
UsingWindowsServer2003R2or2008EnterpriseEdition saves75percentonlicensecostsifyouintendtovirtualize aServerOS. UsingWindowsServer2003R2or2008Datacenter Editionprovidesunlimitedvirtualmachinelicenses.
Power
Eachmachine(serverordesktop)youvirtualizedoesnot drawanymorepowerthanitshost.
Cooling
Eachmachineyouvirtualizedoesnotrequireanymore coolingthanitshost.
DatacenterSpace
Eachmachineyouvirtualizedoesnotrequireanymore spacethanitshost.
Table3-2. PotentialSavingsDuetoVirtualization
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Figure3-4. MicrosoftVirtualizationLicensingCalculatorNumber1
ServerOSbyeditionforoneormorephysicalservers(seeFigure3-5).Relyonthesetools todeterminejustwhatthepotentialsavingsofvirtualizingWindowsServeroperating systemscanbe.Finally,youcanrelyonMicrosoft’sreturnoninvestment(ROI)calculator todeterminethebenefitsyou’llobtainfrommovingtovirtualization. NOTE FormoreinformationontheMicrosoftROIcalculator,gotowww.microsoft.com/virtualization/ ROItool/default.mspx. Inaddition,MicrosofthasmodifiedthelicensingmodeloftheWindowsVistadesktop.ThenewWindowsVistaEnterpriseCentralizedDesktop(VECD)licenseallowsyou torunuptofourvirtualdesktopsperuseratonetimewithonesingleWindowslicense. ItalsoletsyourunanyversionoftheWindowsdesktop.Forexample,youcouldruntwo copiesofVista,onecopyofXP,andonecopyofWindows2000peruserwiththesame license.Thismodelletsyoumanageandmaintainapplicationsthatdonotrunonnewer versionsoftheOSbyplacingthemintovirtualmachinesthatrunolderversions.Youcan learn more about VECD at www.microsoft.com/virtualization/solution-product-vecd .mspx. Inall,evenvendorsofproprietarycodesuchasWindowsunderstandthevalueof virtualization and the need organizations have of reducing their carbon footprint by movingtoadynamicdatacentermodel.
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Figure3-5. MicrosoftVirtualizationLicensingCalculatorNumber2
RelyonNewServerFormFactors Becauseyouneedx64serverslinkedtosharedstorage,youcanbegintoconsiderdifferentserverformfactors.Today,organizationsbuildcomplexmultipurposeserversfor remoteofficesorsmallorganizations.Withvirtualization,younolongerneedtodothis. Forexample,youmightbuildaremoteofficeservertoincludeseveralroles—domain controller,fileserver,printserver,managementserver,databaseserver,andsoon.Buildingsuchaserverrequiresmanycompromises.Domaincontrollersshouldalwaysbeprotectedatalltimes.Havingusersaccessfileorprintservicesthroughadomaincontroller forcesyoutoeitherreducethesecurityoftheserverormakefileaccessmorecomplex than it needs to be. With the advent of virtual machines, you can now separate all of theseroleswithouthavingtopayextralicenses.Butthismeanslookingtonewserver types.All-in-one-serversorserverpods,whichincludetwophysicalservers,network switches,andsharedstorage(seeFigure3-6),areidealforthisscenario,whetheritisfor aremoteorsmalloffice. HP,forexample,nowoffersbladeenclosuresthatcanhostbothserverandstorage bladesinthesameenclosure.Inadditiontheseenclosurescanrunonnormal,110-volt power outlets, no longer requiring special power installations to operate. Right now,
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Figure3-6. UsingaserverpodtohostVMsinsmallorremoteoffices
HPofferstwodifferenttypesofsuchenclosures:thec3000(seeFigure3-7),whichisa half-heightenclosurethatisgoodforasmalloffice,andthec7000,whichisanormal, full-heightenclosure.Tolearnmoreabouttheseenclosures,gotohttp://h20384.www2 .hp.com/serverstorage/cache/536425-0-0-0-121.html.
Figure3-7. TheHPBladeSystemc3000half-heightenclosure,commonlycalled“shorty”
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Figure3-8. TheKellofficeenclosure
Finally,ifyouneedtoplacenewenclosuresinlocationsthatdonothavedatacenters,youshouldlooktonewenclosuremodels.Anothervendor,KellSystems,sellsnew smart enclosures that fit in any office (see Figure 3-8). These enclosures look just like standardofficefurniture,butprovidecooling,power,andspaceinasoundproofcasing foreitherbladeorrack-mountedservers.Thismakesalotofsenseifyouwanttosecure yourhostsystemsbutvirtualizeallofyourworkloads,eveninremoteoffices.Formore informationonKellSystems,seewww.kellsystems.com. Thereisnodoubtthatasyoumoveforwardwithyourvirtualizationproject,looking tonewhardware,oratleastrepurposingexistinghardware,willbesomethingthatyou mustincludeinthevariousphasesofyourproject.
STEP4:ARCHITECTURES Thenextstepintheprocessistoupdateandreviseyourdatacenterarchitectures.Workingwithmultiplevirtualizationlayerscanbecomequiteconfusingiftheyaren’tstructuredproperly.You’vealreadyseenthattherearequiteafewelementstoavirtualized infrastructure.Forexample,toprotectyourvirtualworkloads,you’llwanttousex64systemslinkedtosharedstorageandarrangedintosomeformofhigh-availabilitycluster.
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Butyoucanalsoclusterinthevirtuallayer.Forexample,whenyoubuildanExchange Server2007Mailboxservertostoreusermailboxes,you’llmostlikelywanttotakeadvantageofthefailoverclusteringandreplicationcapabilitiesofthisproducttoensure that the Mailbox service provided by the Virtual Service Offering is highly available. ThesamemightapplytoaSQLServerdatabaseserver.IfyouwantyourWebserversto behighlyavailable,you’llprobablybuildthemintoaNetworkLoadBalancingcluster. Clustersatthevirtuallayerarenotonlygoodpractice,buttheyareoftenamust.That’s becauseanymachinethatisclusteredismucheasiertomaintain—offloadtheworkload toanothermachineintheclustersoyoucanpatchthecurrentoneandsoon.Thismeans systemsmanagementhaslittleimpact,ifany,onend-userproductivity.Andclustering inthevirtuallayerispracticallyfreesinceyoudon’tneedcustomhardwaretosupport it.Keepinmindthatclusteredvirtualmachinesmustusenon-affinityrulestoensurethe twonodesofaclusterdonotresideonthesamehost;otherwise,itwouldbeuselessto clusterthevirtualmachines(VMs)inthefirstplace. Butwhenyoubuildclusterswithinacluster,itcanbecomeconfusing.Anotherexampleofapossiblesourceofconfusioniswhenyoucreatevirtualserverstoprovide servicestovirtualdesktopsthatarerunningvirtualapplicationsinsidevirtualnetworks whilerelyingonvirtualstorage.Quick.Whichlayerisn’tvirtualizedinthisscenario? Toughtoanswer,isn’tit? That’swhereavisualarchitecturecanhelp(seeFigure3-9).Inthisarchitecture,you build seven different layers of virtualization and address each with a particular construct.Thefirstlayeristhephysicallayerandwillincludeeachcomponentwithinthe resource pool. The second is the storage layer and will rely on storage virtualization technologiestoprovisionjustasmanylogicalunits(LUNs)asyouneedforbothphysicalandvirtualresources.Thethirdlayeristheallocationlayer.SinceVirtualServiceOfferings(VSOs)arenothingmorethanasetoffilesinafoldersomewhere,theycanand shouldbemoveddynamicallyfromonephysicalhosttoanotherasadditionalresources arerequiredorwhenmanagementoperationsarerequiredonaspecifichost.Itisthis allocationlayer,orthetrackingofVSOpositioning,thattransformsthedatacenterfrom statictodynamic.Itisalsowithinthislayerthatyoucreateandassignvirtualnetworks basedonyourhypervisor’scapabilities. Thefourthlayeristhevirtuallayer;itiswhereyoudeterminewhatwillbevirtualizedandwilleventuallycometoincludeserverandworkstationworkloads.Thefifth layeraddressesbothphysicalandvirtualresourcemanagement.Keepinmindthatboth resourcelevelsrelyonadifferentsecuritycontext.Inaddition,youmayusedifferent toolstomanagethetwoinfrastructurelevels.ThesixthlayeristhePClayer.Whilemany willmovetovirtualdesktopinfrastructurestoreducethecostofmanagingdistributed systems,otherswillfindthatbymovingtovirtualizedapplications,theentirebusiness modelofdistributeddesktopmanagementispositivelytransformed—somuch,infact, thattheywillnevergobacktoapplicationinstallations. Thelastandfinallayeristhebusinesscontinuitylayer.SinceVirtualServiceOfferings are nothing more than files in a folder somewhere, business continuity practices become much simpler: Just replicate the make-up of every virtual machine to an offsitelocationandyou’llhaveaduplicateofyourentiredatacenteravailableatalltimes. Inaddition, the physical resources in the remote datacenter need not be the same as
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Figure3-9. Integratevirtualizationlayersintoonesingle-servicearchitecture.
thoseintheproductiondatacenter.Afterall,inadisaster,youonlyneedtostartandrun criticalservices.Thisshouldtakeconsiderablyfewerresourcesthanrunningtheentire productionsystem. Thereyouhaveit.Aseven-layervirtualizationarchitecturewitheachlayerbuilding upontheothertosupportthenew,dynamicdatacenter.Nowthatyouunderstandeach layerandwhatgoesintoit,youcanstartbuildingtheinfrastructurethatwillrunit.And, whenyoufeelready,youcanconvertyourphysicalworkloadsintoVirtualServiceOfferingsandcompletelytransformyourdatacenteronceandforall.Ofcourse,thebest placetostartwillalwaysbeinthelaboratory.Testeverythingfullybeforeyoumoveto productionsystems.
STEP5:MANAGEVIRTUALIZATION Thedynamicdatacenterisnowdividedintotwolayers:resourcepoolsandVirtualServiceOfferings.Becauseofthis,operationsshouldbedividedintotwosegmentsaswell. Ifyouhavethestaff,youshoulddedicateseparatestafftomanageeachlayer.Ifnot, youshouldensureadministratorsandtechnicianslearntoweardifferent“hats”when
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workingwitheachlayer.Responsibilitiesaredifferentforeach.Forexample,resource pools(RPs)arenownothingmorethanphysicalresources,includingservers,network devices,andsharedstorage.Peoplewhomanagetheseresourcesdonothavetointeract withendusersthewaypeoplewhomanageyourvirtualworkloadsdo.Endusersdo nothaveanyinteractionwiththeswitchesandroutersinyournetwork,andifso,why shouldtheyhavetointeractwiththeserversthatmakeupyourresourcepools? Organizations must rely on their enterprise architectures to provide complete IT servicestothebusinessestheyrun.Butwithintheenterprisearchitecture,itistheoperationsarchitecturethatmustsupportalloftheotherelementsofthearchitecture(see Figure3-10).Iftheoperationsarchitectureisnotinsynchwiththechangesyoubringto theenterprisearchitecturethroughtheintroductionofvirtualization,yourvirtualization projectwillcollapse.Makesureyouinvolveoperationsfromthebeginningoftheproject toensuretheyareawareofallofthefacetsofITaffectedbyvirtualization.
Figure3-10. TheOperationsarchitectureprovidessupportforallotherarchitectures.
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NOTE Formoreinformationonenterprisearchitecturesandhowtheyinteractwithoperations,see www.reso-net.com/articles.asp?m=8#funder“Architectures.” Thechangesintroducedbyvirtualizationarefar-reaching.Theactivitiesrelatedto VSOsentailseveraldifferenttasks.Securitycontextsarealsodifferent.Yourhostservers canbepartofahighlysecureinfrastructuresinceonlyadministratorsneedtointeract withthem.YourVSOsmustbemorerelaxedsincebothendusersandadministrators mustinteractwiththem. NOTE Foralistofmorethan150administrationtasksforRPsandVSOs,seeWindowsServer 2008:TheCompleteReferencebyRuest&Ruest(McGraw-Hill,2008).
FocusonVMManagement Inaddition,virtualmachinemanagementbringsissuesofitsowntothefore.Becauseof this,youwillneedtoreviewyourmanagementstructure,andindoingso,youwillneed toasktherightquestionswhenyouarelookingfornewmanagementtools.Forexample, considerthefollowingquestions:
▼ HowareVMsourceimagestrackedandupdated?
■ H owareVMsnapshotstracked?Eachvirtualmachinecanincludeupto512 snapshotsofpreviousstates.Ifyouhave1,000virtualmachines,thiscanadd uptoaconsiderableamountofsnapshots.
■ H owaremove,adds,andchanges(MACs)tracked,especiallywhenmachines aredynamicallymovedfromonehosttoanother?
■ H owarevirtualworkloadpoliciespreparedanddeployed?Policiescan includethetypesofresourcesassignedtoavirtualmachine,thepriorityone VMisgivenoveranother,thetimesofdaywhentheVMmusthaveaccessto coreresources,andsoon.
■ A retherespecialdependenciesbetweenapplicationsandVMs?Ifyouhave amulti-tierapplicationrunninginavirtualenvironment,linkingfront-end Webserverstoback-enddatabases,youmustbeawareofvirtualmachine dependenciesandsomustyourmanagementtools.
■ H owissecuritymanagedbetweenresourcepoolsandVirtualService Offerings?Whatkindofsegregationisinplace?Areallcommunicationsto resourceserversencryptedtoprotectpasswords?
■ W hatkindoftroubleshootingsupportdoesthetoolprovidewhenVMsor hostsgodown?Canthetoolidentifyrootcauses—physicalorvirtualor both—oftheproblemsyouface?
■ I sthetoolfullyfunctionalanddoesitprovideaone-stopshop?Canitmanage everyaspectofvirtualization?
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Figure3-11. Themost-requestedtoolstomanageaVMenvironment
■ S houldyouusethesametoolsfortheresourcepoolandtheVSOs?Perhapsa segregationoftoolswouldhelpinsecuringthetwoinfrastructuresseparately.
▲ I sthetoolhypervisor-agnostic?Willitgrowwithyourneeds?Whatifyou needtoimplementnewhypervisorsduetoapplicationsupportpolicies?Can yourtoolaccommodatethesechanges?
You’renotaloneinlookingfortherighttools.Mostadministratorsandmanagersmoving to virtualization are also preoccupied with systems management and support for boththephysicalandthevirtualworld.AccordingtoasurveyperformedbyZiff-Davis ResearchonFebruary18,2008,administratorslookfortoolstosolvespecificmanagementissues(seeFigure3-11).
RELYONTHEVIRTUALIZATIONDECISIONFLOWCHART Nowyou’rereadytobegintheproject.Youhavejustenoughunderstandingtoknow wherevirtualizationcanhelpandhowyoushouldproceed.Eachlevelofvirtualization willbringspecificbenefitswithitsintroductionintoyourdatacenter.However,youneed astructuredapproachfortheimplementationofthethreecoreaspectsofvirtualization: server,desktop,andapplicationvirtualization.Forthis,youneedaspecificdecisionprocess(seeFigure3-12).Thisflowchartaddresseseachimplementationaspectandtiesitto
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Figure3-12. Thevirtualizationdecisionprocess
thebusinessneedyouwishtofulfill.Asyoucansee,itoutlineswhetherthefulfillment ofthebusinessneedwillbeontheserverback-endorthedesktopfront-endandthen proceedsfromtherebasedonhowyouwanttoaddresstheneed. Theremainderofthisbookwillmovethroughthisflowcharttohelpyouunderstand howeachaspectisaddressed.First,you’llneedtoprepareyourphysicalinfrastructure. ThisisaddressedinChapters4,5,and6.Thenyou’llneedtoimplementservervirtualizationinordertosupportbothphysicalserverconsolidationanddesktopcentralization. ThisisaddressedinChapters7and8.Then,onceyourserverinfrastructureisinplace, youcanmovetodesktopvirtualizationthroughtheinstructionsinChapter10.Finally, applicationvirtualizationandtheconceptofthevolatilevirtualdesktopareaddressed inChapters11and12.Theremainingchaptersaddresssecurityandbusinesscontinuity toroundoutyourvirtualinfrastructureanddynamicdatacenter.
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II Build Your Virtualization Infrastructure
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A
syouhaveseeninChapter1,therearealotofreasonsformovingfromaphysical toavirtualinfrastructureforservicedelivery.Traditionaldatacentersarefacing similar issues on a worldwide basis.According to a Network World analysis performedonJanuary7,2008,powerandcoolingcostsinthedatacenterareskyrocketing and need to be controlled (see Figure 4-1). In addition, all datacenter managers agree that:
▼ Physicalserversaretakinguptoomuchroom
■ Physicalserversareunderused,sometimesfrom5to15percent
■ Physicalserversgeneratetoomuchheat
■ Physicalserversneedmoreandmorepower
■ Physicaldatacentersneedcomplexbusinesscontinuitysolutions
■ Downtimeisaconstantissuethatmustbeeliminated
▲ Hardwaremanagementiscomplexandmustbesimplified
Theanswertoallofthesewoesis,ofcourse,virtualization.Virtualizationtransformsthe physicalserverbyincreasingitsworkloadupto80percentwhiledeliveringthesame servicesorganizationshavecometoexpectfromITinfrastructures. Becauseofthis,virtualizationhasadirectimpactonserversales.ResearchfirmIDC predictsthatthethree-yearsalesforecastofserverswillbecutby$4.5million.Originally, IDCprojectedthatthesaleofserverswouldincreaseby61percentby2010,butnowits forecastisdownby31percent. Organizationsarediscoveringthatthebreak-evenpointisthreevirtualmachines perhostserver,andaminimumof15serversneedtobephysicallyconsolidatedtocovertheimplementationcostsofvirtualization.Whilemanyareusingrack-mountedserversforthisconsolidation,bladeserversarealsoaviableoptionsincetheyarefareasier
Figure4-1. Anexampleofskyrocketingpower/coolingcosts
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Figure4-2. Whyimplementservervirtualization?(Source:NetworkWorld,January7,2008)
toimplementoncethebladeenclosureissetup.Organizationsmovingforwardwith virtualizationprojectsreapseveralbenefits(seeFigure4-2). Butmovingtovirtualizationisnotasimpleprojectandmustbeapproachedwith care.Chapters2and3highlightedtheimportanceoftwoaspectsoftheFive-StepProcess forvirtualization:thefirst,Discovery,andthethird,HardwareMaximization.Bothare extremelyimportanttothesuccessoftheproject.Discoveryfuelstheplanningprocess byprovidingtheinputforthechange,andHardwareMaximizationletsyoucreatethe hardwarefoundationthatwillsupportyournewvirtualizedserviceofferings.Bothare addressedinthischapterandthenext.
BEGINTHEANALYSIS The first thing you should do to prepare your physical servers is analyze your IT environmenttoidentifyifareasneedimprovementbeforeyoumoveontovirtualization. Ideally,allofyourphysicalserversarenewerandincludetherightprocessors—those with hardware virtualization capabilities. For Intel, this means a Virtual Technology (VT)–enabledprocessororaprocessorthatincludestheExtendedMemory64Technology (EM64T).WithAMD,thismeansanAMD-V–enabledprocessor.Beverycarefulwhen evaluatingyourserversbecauseiftheydonotincludethesefeatures,youwillnotbe abletorunsomehypervisors.Forexample,youwillnotbeabletorunhypervisorssuch asMicrosoftHyper-VorCitrixXenServeronit;thevirtualizationenginesfromCitrixor Microsoftsimplywon’tloadifyourprocessorsarenotVT-enabled.Nohypervisor,no virtualmachines.
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Insomecases,itmayonlybeamatterofgettingtherightBasicInput/OutputSystem (BIOS)update,aswithAMDprocessors,sinceallofAMD’sprocessorsincludeAMD-V, butitmaynotbeenabledifthesystemdoesnotruntherightBIOSversion.TheBIOS comesfromsystemvendorssuchasHPorDell,soyoumayhavetocontactthemfor more information.As for Intel, it’s much simpler; if your processor does not include EM64T, it simply won’t run high-performance hypervisors and will either need to be relegatedtoanothertaskorbereplaced. NOTE Some early first-generation AMD-V chips do not work with all hypervisors that require hardwareassist.Besuretocheckwiththehypervisorvendorbeforeyoupurchaseasystem. AMDoffersafreeutilitytovalidatewhetheryourprocessorisreadytorunahypervisor.WhiletheutilityisfocusedonMicrosoft’sHyper-V(seeFigure4-3),itspurpose istoseeifAMD-Visenabledontheprocessor;ifitis,theprocessorwillworkforany hypervisor. NOTE ToobtaintheAMDutility,gotowww.amd.com/us-en/Processors/TechnicalResources/0,30_ 182_871_9033,00.html. Inaddition,youmustensurethatyourserverprocessorsusethesamesteppingif youwanttousethemostpowerfulfeaturesofvirtualization,suchaslivemigration— movingavirtualmachinefromonehosttoanotherwhilethevirtualmachineisstill running and delivering services to end users. For VMware, this feature is called VMotion; for Citrix XenServer, it is called XenMotion. This process basically copies allofthein-memoryprocessesfromonephysicalservertoanother.Sincethecontents of memory include processor instruction sets, the process of moving those contents fromonemachinetoanotherwillonlyworkifthetwoprocessorscanhandlethesame instruction set. For this reason, this process will not work between Intel and AMD processors,andinmanycases,willnotworkbetweentwoIntelprocessorsunlessthey havethesamestepping.TheCPUIDdevelopmentsiteincludesautilitythatyoucan
Figure4-3. EvaluatingifanAMDprocessorcanrunHyper-V
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Figure4-4. EvaluatingCPUsteppingvalues
usetoevaluateCPUsteppingvalues,CPU-Z.exe(seeFigure4-4).Runthisutilityon any servers you want to retain as hosting equipment to make sure you can match processorfamiliesintogroupsofhostsystems. NOTE Intel“flexmigration”solvestheIntel-to-Intelmigrationissues.AMDhasasimilarfeature.Both relyonthehypervisorstosupport“featuredisablebits,”whichturnsoffmoreadvancedhardwareassistedvirtualizationfeaturesthatarenotsupportedbyallnodesinthecluster.Thehypervisoryou usewillletyouconfigurethisfeature.Ifthisisimportanttoyou,makesureyoucheckthehypervisor supportforthisfeaturebeforeyouchooseit.Forexample,thefirstversionofMicrosoftHyper-Vdoes notincludethisfeature.However,VMwaredoesitthroughafeaturecalledCPUMaskingwhichispart ofitsEnhancedVMotionCompatibility(EVC)setting.Infact,youcanusethisfeaturetosupportthe livemigrationofVMsfromanInteltoanAMDprocessorandback.
NOTE ToobtaintheCPU-Zutility,gotowww.cpuid.com/cpuz.php.
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Butservervalidationisnottheonlyactivityyourplanningprocessneedstoinclude. Inaddition,youmustevaluateeachofthehardwarelayersthatwillaffectvirtualization, including:
▼ Storage Youmustperformtwoactivitiesatthestoragelevel.First,youcan usetoolssuchastheWindowsFileSystemResourceManager—availablein WindowsServer2003R2and2008—toidentifythestatusofthecontentof yourstoragecontainers:directattached,networkedattached,andstoragearea networks,ifyouhavethem.Thenyoushouldrelyonthisanalysistodetermine whichfilescouldbearchived.Thesecondactivityistolookforstoragethatcan bereusedasvirtualmachinecontainers.Ideally,storagewillbesharedwhen hostingvirtualmachines.Forthis,youmustusetoolsthatcomefromyour storagevendors. NOTE For more information on Windows File System Resource Manager, see http://technet2 .microsoft.com/windowsserver2008/en/library/d6d480ca-18ec-4dee-aafc-a9e7971038cf1033 .mspx?mfr=true.
■ N etworkbandwidth Youshouldidentifythecurrentnetworkbandwidth usage.RelyontoolssuchastheWindowsNetworkMonitor,Windows PerformanceMonitoratthenetworkinterfacecardutilizationlevel,ortools fromthirdparties.Youwanttobeabletoidentifyiftheavailablebandwidth cansupportadditionalworkloads,suchaslivevirtualmachinemigrations,or evenifitcansupportstoragetrafficthroughprotocolssuchasInternetSmall ComputerSystemsInterface(iSCSI).
■ P owerandcooling Youshouldperformapowerandcoolingaudittoensure yourdatacenterinfrastructurecanhandleamovetoavirtualinfrastructure. Theauditwillservetwopurposes.First,itwillactasastartingpointfora potentialrebatefromutilitycompaniesformovingtoavirtualinfrastructure. Second,itwillidentifyanyissueswithyourcurrentinfrastructure.Youcanuse toolsfromAmericanPowerConversionatwww.APC.comtoidentifypossible issuesinthedatacenterinfrastructure.
▲ Hardwareconsolidation Youshouldscanyournetworktoidentifypotential hardwareconsolidationcandidates.Forthis,youcanusethetoolsfrom VMware,Microsoft,orothersasdescribedinsteponeoftheFive-StepProcess. NOTE Enterprise-class consolidation tools can do all of these things. However, tools such as CiRBA’sPlacementIntelligenceTechnologytool(www.cirba.com),whiletheycansupportallofthese functions,areavailableonlyonasubscriptionbasis,withaspecificcostattachedtoeachphysical serveryouruninyournetwork.
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Putasmuchemphasisaspossibleintothesefourstudies.Thevalueofeachstudywill depend on the size of your infrastructure. For example, if you only have 25 physical servers,apowerandcoolingauditmaynotreapasmanybenefitsasifyouhave2,000 physicalservers,butitisstillimportanttoknowthatyourcurrentsystemscanhandle thechangeyouareplanningfor. Remember,ifyouarenotstartingoffontherightfootwithyourvirtualizationproject,youwillrunintoissuesfurtherdowntheroadwhenyourphysicalsystemscannot handletheloadyourvirtualmachinesplaceonthem.Avoidthispitfallandperformindepthanalysesnow. CAUTION Toomanyorganizationsfocussolelyonperformancewhenconductingaconsolidation analysisanddon’tconsidernon-technicallimitationsuntillateintotheconsolidationproject.Items suchassecuritysubzone,sitelocation,departmentownership,servicelevelagreements(SLAs),and evenproductlicensingcanallimpacttheeventualconsolidationplan.Makesureyouincludethemin yourinitialanalysis.
PERFORMASTORAGECONSOLIDATIONSTUDY Asmentionedearlier,therearetwostepstoanystoragevalidationforvirtualization. First,youwanttoscanallstoragetoidentifywhatcanberemovedfromtheinfrastructure. ToomanyITshopssimplycontinuetoaddstoragewheneverspaceissuesarisewithout analyzingwhatitistheyarestoring.Forexample,whenausersendsouta5-megabyte (MB)MicrosoftPowerPointslidedecktotenothersthroughe-mail,youoftenendup withmultiplecopiesofthepresentationinyourstoragesystems.Ifalloftheusersareon thesameMicrosoftExchangemailboxserver,atleastExchangewilldeduplicatetheten copieswithinthee-mailsystem,butassoonasusersareonothermailboxservers,you getmorecopies.Inaddition,someuserswillcopythepresentationtothefilesystem, whichcreatesevenmoreduplicates.Intheend,the5-MBpresentationcaneasilytake upto100MBofspace. When you move to virtualization, you will want to obtain storage technologies thatcansupportdeduplication,notatthebackuplevel,butatthestoragelevel.Virtual machine files often range into multiple gigabytes in size and can take up enormous amountsofspace,butifyourstorageenginecandeduplicatetheircontentsastheyare stored,youwillsavealotonyourdisksubstructure. Thisiswhyfileserveranalysisissoimportant.Ifyoucanrecoverthisspace,deduplicateitems,andotherwisearchiveunuseddata,youcanreleasethestoragespindlesto otherpurposes.Onceagain,thereareseveraltoolsthatcanhelpyouperformthistask. WindowsServerhasincludedaFileSystemResourceManager(FSRM)sincethe2003R2 version.Thisenginecanscanallfileserversandclassifystorageinanumberofdifferentways.Forthistooltowork,eachfileservermustberunningeitherWindowsServer
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Figure4-5. PreparingstoragereportswithFSRM
2003R2or2008andhavetheFSRMengineloadedonit.Storagereportscanberunfrom anyserverinthegroupandcanprovidecomprehensiveinformationonavarietyofdata storageaspects(seeFigure4-5). Severalothertoolsareavailableforthegenerationofstoragereports.Forexample, storageproviderEMCofferstheFileSystemAssessmenttool,whichismostcommonly usedbyconsultingfirmstohelpyoudeterminejusthowmuchofyourstorage—direct attached (DAS), network attached (NAS), or storage area networks (SAN)—is being wastedbystoringthesameinformationmorethanonceor,evenworse,storingunused information. The second part of your assessment identifies storage types. As mentioned in Chapter 3, you most often need to consider shared storage in some way in order tosupportthemostadvancedfeaturesofthevirtualizationenginesavailabletoday
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andprovidehighavailabilityforyourvirtualworkloads.However,notallvirtualworkloadswillrequiresharedstorage.Forexample,youmaydeterminethatsomeoutages areacceptableoncertaintypesofenvironments.Testinganddevelopmentenvironments willoftenrunonDASforsmallernetworksbecausethecostofsharedstorageforthese workloadsissimplynotjustifiable.Inaddition,smallerofficesmayopttocreatevirtual infrastructuresbasedonDAS.Thisispossibleifeachofthedirectattachedcontainersis replicatedtotheothertomakesurevirtualmachinecontentisinsyncbetweenthehosts that share a high-availability configuration. Products such as LeftHand Virtual SAN Appliance(VSA)willletyoureplicatecontentsfromoneDAScontainertoanother.VSA supportsVMwarenow,andwillprobablysupporttheothermajorhypervisorsbythe timeyoureadthisbook.Finditatwww.lefthandnetworks.com. NOTE HPacquiredLeftHandNetworksinOctober2008. MediumofficesmayoptforNASdevices,astheyprovidefilesharingservicesand canbelinkedtomorethanonehost.LargedatacenterswillmostcertainlyoptforSANs sincetheywillrequiretop-levelperformancefromthestoragearrays. Knowing what type of storage is in use, how much storage is available, and how systemsareconnectedtostoragewillgreatlyassistinthepreparationofthehostserver infrastructure.Virtualmachinefilestendtobelargeandwillrequirefastandefficient storagetorunattheirbest.
REVIEWEXISTINGNETWORKBANDWIDTH Withvirtualization,networkusagewillalsochange.Inmanycases,organizationswill opttomovetoiSCSItoconnecttosharedstoragecontainersinsteadofusingthemore traditionalFibreChannelconnectionsthroughhostbusadapters(HBAs).Inthiscase,all storagetrafficrunsoverthenetworkandrequiressignificantlymorethroughputthan networkresourcesalone. In addition, each virtual machine running on a system must have network connections of some type. Virtualization technologies support virtual machine isolation, virtualmachineconnectionstothehostserveronly,orfullconnectivityforthevirtual machine.Thelatterrequiresadditionalnetworkinterfacecardsonthehostserver.Ifa hostisrunning30ormorevirtualmachinesatthesametime,youwillhavetoensure ithasenoughnetworkinterfacecards(NICs)tosupporttheseworkloads.Butyoualso have to make sure your current infrastructure—switches, routers, hubs—support the additional workload at the network layer. In some cases, you may have to upgrade someofthenetworkingcomponentsinyourdatacenter.Onceagain,itwilldependon theworkloadyouplantorunatthevirtuallayer,butthisanalysisisalsojustasimportantasanyoftheothers.
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Therefore,whenyouscanyourcurrentnetworkstatus,youshouldtrytoanswerthe followingquestions.
▼ W hichservicesarerunningandwhatbandwidthdotheyrequire?Forexample, ifyouarecurrentlyrunningtechnologiessuchasMicrosoftExchangeServer 2007orSQLServer2008,youmayalreadyhavesetupreplicationpartnersin remotesites.Addingtothisworkloadmayputtheworkloadatrisk.
■ M ovingmemorycontentsfromonehostservertoanotherputsastrainon yourphysicalserversaswellasthenetwork.TechnologiessuchasVMotionor XenMotionoftenrequirenetworkpathsoftheirowntofunctionadequately.Is yourinfrastructurereadytosupportthisadditionaltraffic?
■ I fyouchoosetorelyonsharedstorageandaccessitthroughiSCSI,willyour networkingequipmentsupporttheadditionalload?
▲ H owoldareyourswitchesandrouters?Areanyupgradesrequired?Areany portsleft?
Theanswerstothesequestionswillhelpyouassesswhatyouwillrequireatthenetworkinglevelwhenyoupreparethehostenvironment.
PERFORMAPOWERANDCOOLINGAUDIT Oneofthemostattractiveaspectsofvirtualizationandphysicalserverconsolidationis thepotentialpowersavings.Powersavingsarecalculatedonaper-serverbasis.Utility companieshavedevisedanequationtocalculateyourpotentialpowersavings: SavingsPower=E$[(STTLPWR)Before–(STLLPWR)After]
Table4-1explainsthevaluesusedintheequation. NOTE For more information on calculating potential power savings, look up Virtualization: The MostImpactfulSolutiontotheDataCenterPowerCrisisbyVMwareatwww.vmware.com/files/pdf/ Energy_Efficiency_WP.pdf. AccordingtoIDCprofessionalJohnHumphries(datareleasedin2007),thestate ofthedatacenterinfrastructureissuchthatthereisnow$140billioninexcessserver capacity,whichiscomparabletoathree-yearsupplyofservers.Powerexpenditures are an average of $0.50 for every $1 dollar spent on server acquisitions. More than $29billionisspentonpowerandcoolingindustry-wide.Spaceisalsoatapremium. Server space in the datacenter costs $1,000 per square foot, $2,400 per server, and $40,000perrack.Operatingcostsrangeupto$8inmaintenanceforevery$1spent on new infrastructure components. The current server administration ratio is 20 or 30serversperadministrator.
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Input
Description
Perform a Comprehensive Analysis
DefaultValue
STTLPWR Standardpower Before/After ratingsforservers 1CPU:475W/550W 2CPU:550W/675W 4CPU:950W/1150W 8CPU:1600W/1900W 16CPU:4400W/5200W 32CPU:9200W/11000W
Source Frommanufacturer’s Websitesinserver specifications.Can alsouseatoollike Dell’sDataCenter CapacityPlanner.
E$
Priceperhourof $.0813(averageinU.S. 1kWofelectricity in2005)
Energyinformation administration
λ
Constant
APCestimate
.67(deltabetween, beforeandafter)
Table4-1. CalculatingPotentialPowerSavings
Reducingthisfootprintandincreasingthevaluederivedfromhardwareisamust. Thisiswhypowerandcoolingassessmentsareimportant.Theyhelpintwoways.
▼ F irst,theygiveyouanideaofhowyourinfrastructurecanhandlethemoveto virtualization.
▲ Second,theyprovidethepotentialforrebatesfromyourutilitycompany.
Manyorganizationshaveneverperformedapowerandcoolingassessment,andmay beatalossastohowitshouldbeapproached.Fortunately,APCoffersseveralfreetools tohelpoutinthiscase(seeTable4-2).Thesetoolsfallintothreecategories.Thefirstare calculators,which,onceyouprovidethemwithinput,willprovideestimatesofcosts. Thesecondareselectors,whichhelpyouchoosehowtoorganizedatacentercontents. Thethirdareillustrators,whichprovidegraphicaloutlinesofyourchoicesandcalculations.Eachhasvalue. NOTE For more information on APC TradeOff Tools, see www.apc.com/prod_docs/results .cfm?DocType=TradeOff%20Tool&Query_Type=10. TheDataCenterCarbonCalculatorisusedtoidentifyyourcurrentcarbonfootprint (seeFigure4-6).Itreliesontheinputsyouprovidebasedonpotentialscenariostooutlinejusthowmuchcarbondioxide(CO2)yourdatacenterproducesandwhatitsequivalentinautomobileoutputis.
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APCProduct
Description
DataCenterCarbon Calculator
Identifytheimpactofchangesindatacenterefficiency onenergycostandcarbonfootprint
DataCenter EfficiencyCalculator
Identifytheimpactofalternativepowerandcooling approachesonenergycosts
DataCenterCapital CostCalculator
Identifytheimpactofphysicalinfrastructuredesign changesoncapitalcosts
VirtualizationEnergy Identifytheimpactofservervirtualizationand CostCalculator datacenterdesignchoicesonenergyandspacesavings DataCenterPower SizingCalculator
Identifytheimpactofserverandstorageconfigurations onITloadcapacityandrequiredutilityinputpower
DataCenterInRow ContainmentSelector
Identifytheimpactofpreferencesandconstraintson therecommendedcontainmentapproach
Table4-2. APCTradeOffToolsfortheDatacenterInfrastructure
Figure4-6. DataCenterCarbonCalculator(CourtesyofAPC)
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Figure4-7. DataCenterEfficiencyCalculator(CourtesyofAPC)
TheDataCenterEfficiencyCalculatoralsoreliesoninputyouprovideaboutyour datacenterconfigurationtohelpdeterminewhereyoustandinoveralldesignandutilizationefficiency(seeFigure4-7).Thiscalculatorisusedtovalidatethatyourcurrent datacenterconfigurationisasefficientaspossible. The Data Center Capital Cost Calculator helps you when you plan infrastructure changestoyourdatacenter(seeFigure4-8).Ifyoudeterminethatyourdatacenterdesign isnotasefficientasitcouldbe,youcanrelyonthiscalculatortohelpdeterminewhich changesofferthebestvalueforthecost. The Virtualization Energy Cost Calculator is probably the most valuable calculatorinthisgrouping,sinceitoutlinesjusthowmuchpowerandcoolingyouwillsave
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Figure4-8. DataCenterCapitalCostCalculator(CourtesyofAPC)
basedonvirtualizationtechnology(seeFigure4-9).Itsmostvaluablecomponentisthe graphicsoutliningtheimpactonyourvirtualizationbill.Notethatyoumustrelyon theinformationoutlinedinChapter7toproperlydetermineyourserverconsolidation ratio,sincenotallhypervisorsarecreatedequalandwillnotsupportasmanyvirtual machinesperhost. Sinceyouwillbechangingserverandstorageconfigurationsinsupportofvirtualization,theDataCenterPowerSizingCalculatorwillhelpdeterminewhatimpactthese newconfigurationswillhaveonyourdatacenter(seeFigure4-10).Relyonthiscalculator tohelpdeterminethebestconfigurationsthatsuityourenvironment.
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Figure4-9. VirtualizationEnergyCostCalculator(CourtesyofAPC)
Finally,theDataCenterInRowContainmentSelectorwillhelpyoudeterminethebest containmentapproachforyourserverracksasyoupreparethemtohostvirtualization infrastructures(seeFigure4-11).UseitinconjunctionwiththeDataCenterPowerSizing Calculatortohelpdetermineyourbestandmostefficientrackconfigurations. Whileyoumaynotbeusedtodatacenteranalytics,thesefreetoolsmakethemeasy andstraightforward.Attheveryleast,youshoulddeterminethecarbonfootprint,the efficiencyofyourdatacenter,andthepotentialsavingsvirtualizationwillbring. NOTE RememberthatyoucanalsorelyonMicrosoftAssessmentandPlanningToolkit(MAP)to performpowerassessments.
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Figure4-10. DataCenterPowerSizingCalculator(CourtesyofAPC)
Figure4-11. DataCenterInRowContainmentSelector(CourtesyofAPC)
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RELYONOTHERTOOLS There are also other tools you can rely on to obtain more information. For example, VMwareoffersafreeonlineTotalCostofOwnership(TCO)/ReturnonInvestment(ROI) Calculator,whichwilltakeyouthroughaseriesofquestionsaboutyourenvironment to help you determine the payback for a virtualization project (see Figure 4-12). This calculator is useful because it helps you budget your project and identify potential projecttimelines. NOTE FormoreinformationontheVMwareTCO/ROICalculator,seewww.vmware.com/products/ vi/calculator.html.
Figure4-12. TheVMwareTCO/ROICalculator
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Tools
Description
OptimizationSelfAssessmentTool
Toolthatanalyzesyourinfrastructureandplatform. Itprovidesareportthatincludesapersonalizedand privateoptimizationscore,peercomparison,andvalue assessmentforyourorganization.Findoutmoreatwww .microsoft.com/optimization/tools/overview.mspx.
Infrastructure Optimization(IO)
IOisthecustomerexecutionpathMicrosoftofferstohelp businessesdrivetowardsdynamicsystemscapability. Findoutmoreatwww.microsoft.com/io.
TheDynamic SystemsInitiative (DSI)
DynamicSystemsisMicrosoft’svisionforwhatanagile businesslookslikeandwhatyoushoulddrivetowards becomingasabusinesstomeetthedemandsofadynamic businessenvironment.DSIisMicrosoft’stechnology strategyforproductsandsolutionsthathelpbusinesses increasetheirdynamiccapability.Findoutmoreatwww .microsoft.com/business/dsi/default.mspx.
Table4-3. AdditionalSourcesofInformationfromMicrosoft
Inaddition,Microsoftoffersseveralothersourcesofinformationandtoolsthathelp identifythepotentialsavingsphysicalserverconsolidationoffers(seeTable4-3). Of the three sources of information, the most useful for data collection is the OptimizationSelf-AssessmentTool.Itoffersthreeoptionsforevaluation.ThecoreinfrastructureoptionfocusesonbaseITservices,suchasidentityandaccessmanagement, devicemanagement,securityandnetworking,dataprotection,andsecurityprocesses (seeFigure4-13).Itisusefulfortheevaluationofyourbaseinfrastructureandhelps identifyanymissingcomponents.
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Figure4-13. TheMicrosoftCoreInfrastructureOptimizationAssessmentsurvey
TheBusinessProductivityInfrastructureAssessmentfocusesonproductivityservices, suchascollaboration,unifiedcommunications,contentmanagement,businessintelligence, andsearchservices(seeFigure4-14).ItisusefultoidentifyhowyourITservicessupport yourbusinessprocesses. Finally,theApplicationPlatformAssessmenthelpsyoufocusonfuturegrowth and customization through development, Service-Oriented Architectures (SOA),
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Figure4-14. TheMicrosoftBusinessProductivityInfrastructureOptimizationAssessment
datamanagement,userexperienceevaluationsand,onceagain,businessintelligence (seeFigure4-15).Thisassessmentprovidesvaluefororganizationsthathavecustom requirements. Eachofthesetoolsprovidesadditionalinsightintoyourexistinginfrastructureand servicesandthepotentialchangeyoucanimplementwhenyoumovetoavirtualinfrastructure.
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Figure4-15. TheMicrosoftApplicationPlatformOptimizationAssessment
PERFORMASERVERCONSOLIDATIONSTUDY Anothervitalsteptotheprojectistheserverconsolidationstudy.Aspointedoutin Chapter 2, you must have a thorough understanding of your current service infrastructure to move to virtualization. You must identify the following components in thisstudy:
▼ Categoriesofserversprovidingspecificservices
■ Linksbetweenapplicationsanddependencies
■ W orkloadtypes,withaspecificfocusontheresourcesrequiredtosupport aspecificworkload,beitmemory,CPU,diskaccess,ornetworkaccess
■ Workloadpeakhours,aswellasdurationofthepeaks
■ Workloadschedules,betheydaily,weekly,monthly,orevensemi-annual
▲ S pecialworkloadrequirements,suchascustomhardware,donglesfor applicationactivation,andsoon
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Thesevalueswillhelpplanhowyourworkloadswillbemigratedtoavirtualenvironment and where they can reside. One of the most important aspects of virtualization planningisvirtualworkloadpositioning—makingsurethatthehostserver’sresources areusedappropriatelybythevaryingworkloadsitrunsandmanages.Forexample,if oneoftheworkloadsrequiresnetworkresourcesearlyinthemorning,youneedtomake suretheotherworkloadsdonotcontendforthesameresources.Youcanonlyplanthis whenyouhaveidentifiedworkloadcharacteristics,asoutlinedpreviously.
IdentifyAppropriatePerformanceMetrics Whenyoucollectdataaboutyourworkloads,itwillbeessentialtoidentifytheappropriateperformancemetricsifyouwanttogainanappropriateunderstandingoftheworkloads you will be transforming. If your workloads are running on Windows, you can relyontoolssuchasthePerformanceconsole.Itallowsyoutocapturedataonhowyour serversperformonaregularbasis.ThegreatthingaboutthePerformanceconsoleisthat itsupportstheevaluationofeverysinglefacetofaworkload,includingCPU,memory, disk,andnetworkresources. YoucancreateaPerformanceMonitoringconsolethatautomaticallytracksresource usageonallservers.Thisconsolewillneedaccessrightstoperformancecountersoneach server you monitor, so it is best to use administrative privileges to launch the PerformanceMonitorconsole(onWindowsServer2008,gotoServerManager|Diagnostics| ReliabilityandPerformance|MonitoringTools|PerformanceMonitor)andthenproceedasfollows:
1. Usetheplussigninthetoolbartoaddacounter.
2. I ntheSelectCountersFromComputerfield,typethenameoftheserveryou wanttoview.RemembertousetheUniversalNamingConvention(UNC) name,forexample,\\ComputerName.
3. S electtheperformanceobjectandthecounter(clickthedownarrowtoview counters),andclickAdd.
4. Repeatforanyotherserveryouwanttoinclude.ClickOKwhendone.
5. N owthatalltheserversareadded,useMoreActions|New|DataCollector Setfromtheactionpane.
6. N amethecollectorset“ServerMonitoring,”clickNext,saveitinthedefault location,andclickNextagain.
7. I nthenextdialogbox,clickChangeunderRunAstoaddappropriate credentialstothiscollectorset.ClickOK.
8. ClickSave,clickClose,andclickFinish.
9. T orunthecollector,movetoServerManager|DiagnosticsReliabilityAnd Performance|DataCollectorSets|UserDefined.Right-clickyourcollector set,andselectStart.
10. Runitonaregularscheduletoreviewresourceusageonyourservers.
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The items you include in your monitoring should contain the following elements for eachserverinyournetwork:
▼ Logicaldisk,Freediskspace(%freelogicaldiskspace)
■ Logicaldisk,Disktime(%logicaldisktime)
■ Logicaldisk,Diskreadsandwrites
■ Logicaldisk,Diskqueuing(averagediskqueuelength)—activebydefault
■ Memoryusage(availablememorybytes)
■ Memorypaging(memorypagespersecond)—activebydefault
■ Networkinterface(currentbandwidth)
■ Networkinterface(outputqueuelength)
■ Networkinterface(packets/sec)
■ Pagingfileactivity(%pagingfileusage)
■ Physicaldisk,Diskqueuing(averagediskqueuelength)
■ Physicaldisk(splitIO/sec)
■ Processorusage(%processortime)—activebydefault
■ Processorinterrupts(processorinterruptspersecond)
■ Serverpagedpool(serverpoolpagedpeak)
■ Serverservice(totalserverbytespersecond)
■ Serverworkitems(serverworkitemshortages)
▲ Serverworkqueues(serverworkqueuelength)
UsetheExplainbuttontolearnwhateachsettingrefersto.Monitorthesesettingsover timetoidentifyhowyourserversandtheirworkloadsperform.Anappropriateschedulewouldincludethefollowing:
▼ W eekdaysatpeaktimes,suchas7:00A.M.to9:00A.M.,11:00A.M.to2:00P.M., and3:30P.M.to6:00P.M.
■ Weekdaysatnon-peaktimes
■ W eekendsatvarioustimes,suchasSaturdayafternoon,Sundaymorning,and Sundayafternoon
▲ Weeknightsatthetimesyourbatchjobsrun
Runthescheduleoverthecourseofatleastonemonth.Thescheduleshouldalsoinclude yourbusinesscycles.Ifyouhavespecialbusinesspeaks,youshouldtakethemintoaccountinyourevaluation.Combinethedatafromthisanalysiswiththedatafromother analysistools,asdiscussedinChapter2.
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InterprettheResults Thedatayoucollectwillincludeseveraldifferenttypesofoutput.Interpretingthisdata willdependonthesourceofthedataitself,forexample:
▼ D atayoucollectfromMicrosoftMAPcanbeinterpreteddirectly,sinceit provideschartsandreportsthatarespecificallydesignedforthepurposeof physicalserverconsolidation.
■ D atayoucollectfromeitheroftheVMwaretools—GuidedConsolidationor CapacityPlanner—canalsobeinterpreteddirectly,sincetheyarealsocreated forthepurposeofphysicalserverconsolidation.
▲ D atayoucollectfromtheWindowsPerformanceconsoleoftenrequires additionalprocessinginordertoprovideappropriateresults.Notethe followingitems:
■ I fyourAverageDiskQueueLengthisthreeorgreater,yourdisksare overworked,unlessyoudonothaveenoughmemoryintheserveranddisk thrashingiscausedbyvirtualmemoryswapping.
■ I fthe%ProcessorTimeisconsistentlylowandtherearealotofidletimes, theprocessorisunderused,unlessthereareotherbottleneckscausingthe processortowaitforinstructions.
■ I fMemoryUsageishighandPageFileSwappingisconsistent,your serverdoesnothaveenoughmemoryandmorewillberequiredwhenitis virtualized.
■ I fyourNetworkInterfaceisconsistentlybusy,theworkloadisnetworkintensiveandwillrequiremorethanonevirtualNIConceitistransformed. Note,however,thatthisvaluedependsonthesourcephysicalNICspeed.If youmovethephysicalmachinetoavirtualmachinethatresidesonahost using10-gigabyte(GB)EthernetNICs,andtheoriginalmachineranona 100MBNIC,theproblemmaygoawayonitsown.
Bringallofthedatatogethertoattempttocreateaglobalpictureofyourworkloads.Also makesureyouaddyourownunderstandingofyourbusinessprocessestotheoverall report.Finally,payattentiontocustomhardwarecomponentsbecausetheywillrequire specialapproachesduringthetransformationoftheworkloads. YouraimistocreateaBasicConsolidationEstimate(BCE),whichcategorizesallof yourworkloadsandidentifieshowandwhentheywillbetransformed.
RATIONALIZEEVERYTHINGAGAIN Nowthatyouhaveyourevaluationinformationinhand,youcanrelyonyourserver inventoryinordertoidentifywhichserverscanberationalized,whichcanberetired, andwhichneedtobereplaced.That’sright;thefirststeptostartwithoncetheinventory iscollectedshouldberationalization.Youshoulduseyouranalysistoidentify
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▼ ServerswithpoorCPUutilization.Theseareallcandidatesforvirtualization.
■ Theserversthatare“atrest.”Thesemaybecandidatesforremoval.
■ T heserversthatcanbesimplyshutdown.Theseareadditionalcandidatesfor removal.
■ T heserversthatarethebestcandidatesforvirtualizationandwhosehardware willnotbereusableasahostserver.Thisshouldincludemostworkloads.Only uniqueworkloadscannotbenefitfromvirtualizationtoday.
▲ T heserversthatarecandidatesaspotentialhosts.Thisshouldincludethe newestserverswithsimilarprocessorcapabilities.
Thiswillhelpyoucategorizeallservers.Youshouldcreatebatchesofserversandfrom thosebatchesidentifythebestvirtualizationcandidatesbasedonthecomplexityoftransformation,fromeasytomoderatetodifficult.Finally,rationalizeeverythingbygetting ridofanythingyoucan.Don’tforgettheeasiestservertomanageistheonethatisnot there.Also,rememberthatwhileyoukeepserversonhandinthephysicalworldbecause oftheircomplexityofpreparation,inthevirtualworld,you’llbeabletocreatevolatile serversmuchmoreeasily.Volatileserversareserversthathaveashortdurationperiod andarecreatedforspecifictime-basedpurposes.Oncethepurposeisdone,theservercan simplydisappear.Whileyoucan’tdothisinthephysicalworld,itisdefinitelypossiblein thevirtualworld.Forthisreason,youmaybeabletoremovesomeofthephysicalservers thatwerebeingkeptaround“justincase.” TIP Sinceyouwillbemovingtoavirtualordynamicdatacenter,youwillmostlikelytakeadvantage of the possibilities of physical-to-virtual (P2V) migrations. For example, Microsoft System Center Virtual Machine Manager (SCVMM), located at www.microsoft.com/systemcenter/scvmm/default .mspx,hastheabilitytocapturephysicalmachineimagesandconvertthemtovirtualmachines.This isquiteusefulforbothtestingandpreparingforyournewVirtualServiceOfferings(VSO)environment. Ifyourelyonanon-Microsofthypervisor,suchasthatprovidedbyVMwareorCitrix,youcanuseother migration tools.VMware offers the freeVMware Converter (www.vmware.com/products/converter); Citrix also includes a conversion capability within the XenCenter console, but it can also rely on SCVMM,sinceitsupportsthesamevirtualmachineformatasMicrosoftdoes. A server today provides a function. It is not a product. Many organizations have taken to single-instance servers when working with older versions of Windows. This approach started with Windows NT. Though NT itself was a solid product, many of theoperationsorapplicationsorganizationsperformedwithitmadeitunstable.Often, thebestwaytodealwiththisinstabilitywastodedicatetheservertoonespecificrole. Anotherreasonforthisapproachwasproject-basedhardwareacquisitions—eachtimea newprojectrequiredaserver,itwouldacquireitsownandaddoneormorenewsinglepurposeserversintotheproductionnetwork,aswellascreatingtestanddevelopment environments of its own. Unfortunately, the single-purpose-server approach works to increasethenumberofserversintheorganizationtothepointofproliferation.Many existingserversareneverusedtotheirfullcapacity.
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Consolidationinvolvesfewer,fatterservers.Fewerserversmeansimplermanagement.Youcanimproveservicelevelsbecauseitiseasiertomaintaintheoperationofa fewcentralizedserversthanitisforseveraldistributedservers.Thereislessdowntime, sinceserverstendtobecentralizedandprovideeasierphysicalaccess.Applicationscan bedeployedmorerapidlybecausemostofthecoderesidesontheserveritself.Itiseasier tostandardizebecausefewerphysicalelementsareinvolved.And,withvirtualservers, youcaneasilymoveonevirtualinstanceofaserverfromonephysicalhosttoanother, providingdynamicresponsestoincreasedbusinessneeds. Therearefourjustificationsforconsolidation.
▼ Centralization Relocatingexistingserverstofewersites.
■ P hysicalconsolidation Manysmallerserversarereplacedwithfewer,more powerfulservers.
■ D ataintegration Severaldistributeddatabasesareconsolidatedintoasingle datarepository.
▲ Applicationintegration Multipleapplicationsaremigratedtofewer,more powerfulservers.Applicationsmusthaveacertaindegreeofaffinitybefore thisintegrationcanoccur.
Throughtheuseofvirtualizationtechnologies,youwillbeabletotakebetteradvantage ofasingleserver’shardwarebyinstallingmultipleinstancesofoperatingsystemsinside virtualmachines.Onaverage,youwillbeabletorunbetween10to20virtualmachines perphysicalhost,depending,ofcourse,ontheconfigurationofthephysicalhostandon thehypervisoryouchoose. Keepinmindthatavirtualizationprojectis,bydefault,aphysicalserverconsolidationproject.Butyoucan,throughdiligenceandeffort,turnitintoaserverconsolidation projectthroughrationalization.Getridofanythingyoucan.Thismakesalotofsense whenyouthinkofsomeoftheworkloadsyourun.Trytorationalizethenumberofservers you virtualize, especially multiple development and test environments, as well as serversthatrunsingleworkloads,ifyoucan.
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O
nce you’ve completed your analysis and you’re ready to proceed, you can looktotheconceptionandbuildingofyourresourcepool.You’llneedtoplan carefullyintermsofwhatyouwillactuallyvirtualize,whatyou’llneedinplace tobegin,andwhereyou’llstartvirtualizing.Todoso,you’llmostlikelyneedtoupdate yournetworking,storage,andperhapsserverinfrastructure.Then,whenyoufeelyou’re ready, you’ll want to put a laboratory in place and get set to actually virtualize your infrastructures,after,ofcourse,intensivetesting. Thecomponentsofyourresourcepoolwillvarygreatly,dependingonseveralfactors. Small organizations with fewer than 50 servers will want to put less expensive infrastructures in place and will probably not need the levels of high availability that largerorganizationswilllookfor.Mediumorganizationswillwanttolooktomorerobustinfrastructures,andlargeorganizationswillwanttoputinplacetheverybestthere is.Everythingdependsonbusinessneedandbudget.Thosewithlowbudgetscanstill moveforwardandachieveamazingresults.Thosewithappropriatebudgetswillbeable tomovetothelatesttechnologiesandcreateveryresilientinfrastructures. Inaddition,thehypervisoryouchoosewillhaveanimpactonhowyouwillproceed. Notallhypervisorsarecreatedequaland,therefore,havesignificantlydifferentcharacteristics.ThistopicisexaminedindepthinChapter7,andyouwillwanttoexaminethis chapterindetailbeforemakingyourfinalchoicesfortheconfigurationofyourresource pool.AsstatedinChapter1,youwillmostlikelyendupusingmorethanonehypervisor,unlessyouareasmallshoporyouhavecompletecontroloveryourtechnological choices.Thelatterisseldomseen,aspoliticalpressuresfromothersoftentendtoinfluencetechnologicalchoiceseventhoughtheirargumentsleavealottobedesired.Because ofthis,manyenduprunninghybridinfrastructuresthatdon’treallymeshwelltogether, buttheyhavenochoice.Politicalpressureornot,makethemostofyourchoicesand validatethemasmuchaspossible.Homogeneousinfrastructuresarealwaystheeasiest tomanageandprotect,butifyoufindyouhavetobuildaheterogeneousenvironment, focusonthemanagementtoolsyouchoose.Chapter16willbeofgreathelptoyouin thistask.
PLANNINGANDPREPARATION Oneofthemostimportanttasksyou’llperformonceyouhavetheinventoryisdetermininghowtoapproachyourvirtualizationproject.Thisinvolvesidentifyingwhatto virtualizeandinwhatorder.Thiswillformthestructureofyourvirtualizationproject. Startsmallandbuildupuntileverythingyouwanttovirtualizeisvirtualized.
WhattoVirtualize Whenyouareplanningforvirtualization,oneofthefirstquestionstoaskiswhichservers canIvirtualize?It’seasy.Mostserverworkloads,eventhosethatrequirecustomhardware,canbevirtualized.However,thereareexceptions.
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▼ S erversutilizingmorethaneightCPUcoresmayposeachallenge.Ifyouhave physicalworkloadsthatarerunningonmorethaneightCPUcores,youwill notbeabletovirtualizethemas-isbecausethemaximumnumberofprocessor coresaddressedbyvirtualmachinesiseight.However,youcancircumvent thislimitationinoneoftwoways.
■ I fyourphysicalserverdemonstratesthatitdoesnotactuallyrelyonmore thaneightcores,youcaneasilyvirtualizeit.
■ I fyourphysicalworkloadusesallofthecoresitcurrentlyhas,theremaybe awaytosplitupthefunctionsitrunsintomorethanonevirtualmachine, lettingyouvirtualizetheworkloadanyway.Forexample,aserverrunning MicrosoftExchange2007mayrunwithmorethaneightcores,butsince Exchangeisdesignedtorunuptofourdifferentworkloads,eithertogether orapart,youmaybeabletosplitworkloadsontomorethanonevirtual machine,lettingyouvirtualizethesystem.
■ S erversutilizingmorethan85percentoftheirphysicalresourcesmaypose achallenge.Onceagain,ExchangeServerprovidesanexcellentexample.If yourExchangeserverisrunningwithmostoftheresourcesonthephysical system,youmayopttokeepitas-is.However,virtualizingitwillgiveyou severaladvantages—liberationfromphysicalconstraints,possiblereplication forsystemprotection,easybusinesscontinuity—andforthisreason,youmay wanttovirtualizethesystemanywayevenifitturnsouttobetheonlyvirtual machinerunningonahost.
▲ S erversthatrequirecustomhardware,suchasUniversalSerialBus(USB) donglesormodemsmaybehardtovirtualize.However,therearetechnologies thatsupportthevirtualizationofthesedevices.
■ U SBportscanbevirtualizedbecausemostmodernhypervisorswill supportvirtualUSBports.IfyourapplicationrequiresaUSBporttoappear asalocaldevicesothatitcanrecognizethedongleitrequiresforlicensing purposes,youcanturntocustomhardware,suchasDigi’sAnywhereUSB, tocreatededicatedUSBportsoverInternetProtocol(IP)connectionsfor virtualmachines(VMs)thatrequirethem.Findoutmoreatwww.digi.com/ products/usb/anywhereusb.jsp.
■ C allcenterservers,faxservers,androutingandremoteaccessserverscan alsobeachallengebecausetheyallrequireaccesstomultiplemodems.While hypervisorscanvirtualizeserialports,youstillneedtoattachthemtothe modems.Youcanrelyontwoproductsforthis.VirtualModemProwillcreate virtualizedIPmodems.Findoutmoreatwww.eltima.com/products/virtualmodem-pro.Digialsooffersserialcardsthatcanbeusedtocreatemultiple modementrypoints.Findoutmoreatwww.digi.com/products/serialcards.
Asyoucansee,therearechallengestovirtualizing100percentofyourworkloads,but theycanbeovercome.Rememberthatifyouneedspecialhardware,youwillneedto createatleasttwohostserverstosupportthisroletoprovidehighavailabilityforthe servicesthatdependonthem.
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ReplaceAnythingBeige When you pose the question of what should you virtualize, the answer is still easy: everythingyoucan.However,you’llwanttostartwithspecificsteps.
▼ C onsiderstartingwithserversthatarechronicallyreconfigured.These areoftentestordevelopmentenvironments,becausetheyareregularly reconfiguredorevenreprovisioned.Whilethesetasksarearduousinthe physicalworld,theybecomeasnapinthevirtualworldsinceyoucaneasily duplicatevirtualmachinesandyouhaveaccesstoundoabledisks,which makesreconfigurationsasnap.Considerusingsomeofyourexistinghardware ashostsfortheseworkloadssincetheywillnotneedthehigh-availability levelsthatproductionsystemswill.
■ T henmoveontolow-hangingfruit.Thisincludesanything“beige,”anything withoutblinkinglights,oranythingwithlowutilizationratios.Thisoften includesworkloadssuchasfileorprintservers,Webservers,andsmall departmentalapplications.Evenhome-grownapplicationsareexcellent candidatesforthefirstphaseofvirtualization.Inaddition,domaincontrollers oridentityserversareidealcandidatesforvirtualizationsincetheiroperational modelismanysmallserversthatprovidebuilt-inredundancyservices.
■ N ext,looktohigh-risklegacyservers—anyserversthatrunapplicationsthat, forsomereason,cannotbeupgradedandmustrunonolderoperatingsystems. Hopefully,you’renotstillrunningarchaicoperatingsystemssuchasWindows NT,butifyouare,thereisnobetterWindowsNTthanavirtualizedWindows NT.OnceyoucreateavirtualizedNT,itismuch,mucheasiertoduplicateit onanas-neededbasis.Trydoingthatonaphysicalbasis.Legacyapplications oftentendtobeessentialtothebusiness,butalsotendtohavelowutilization workloadsbecauseoftheirverynature.Theyareexcellentcandidatesfor virtualization.
▲ K eepcomplexworkloadsforlast.Workloadsthataremoreresource-intensive, suchase-mailservers,databaseservers,orevenclusteredservers,aremore difficulttoconvertsincetheyrequiremoreadvancedknowledgeofthe virtualizationplatformandtheyoftenoffermission-criticalservices.Practice withthesmallerworkloadsfirstandthenmovetothemorecomplexworkloads whenyouhavemasteredthehypervisoryou’reusing.Theseworkloadswill alsousuallyincludeserversthathavecustomhardwarerequirements.
Make sure you understand the input and output per second (IOPS) requirements for each of the workloads you are virtualizing. This will let you create proper virtual machineconfigurationsinsupportoftheapplicationsasyoutransformthem.
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ChoosetheImplementationMethod Youcanchooseamongseveraldifferentimplementationmethods.Atfirst,whenorganizationswerepioneeringvirtualization,theyrequiredalotofexternalhelp.Manyorganizationsoptedtoimplementvirtualizationthroughpartnersbecauseitwasanuntested fieldandlittleknowledgeaboutthedifferentproductswasavailable.Today,thestory isdifferent.Justthefactthatyouhavethisbookinhanddemonstratesthatknowledge aboutvirtualizationissignificantlyeasiertoaccess. Therearestillthreedifferentimplementationscenarios,however.
▼ Y oucandoeverythingonyourown,learningaboutthedifferentvirtualization technologies,choosingaplatform,andthenmovingforwardthroughaphased approach.
■ Y oucanhireapartnertogiveyouajumpstart.Jumpstartprogramsareuseful sincetheygiveyouaheadstartbybeginningtheprojectforyouandthen makingthedifferentphasesoftheprojecteasiertoaccess.Attheendofthe jumpstart,youhaveconfiguredhostsystems,asampleofvirtualizedservers, andsomebasictrainingforyourpersonnel.
▲ Y oucanoutsourcetheentireproject.Thismodelusesoutsideresourcesto performeachphaseoftheproject.Manyorganizationsfeelmorecomfortable withthisapproach,butkeepinmindthatifyouareoneofthem,yourchoice ofpartnersmustbecarefulindeedbecauseonlypartnerswiththeright experiencewillperformwellinthisproject.Onceagain,thisbookcanhelpby givingyouguidanceandidentifyingwhereyouneedtowatchforpitfalls.
Whichyouchoosewillonceagaindependonwhoyouare,thesizeofyourorganization, thebusinessneeddrivingthevirtualizationproject,andyourbudget.Thereisnothing wrongwithdoingityourself,justasthereisnothingwrongwithoutsourcing.However, wecannotstresshowimportantyourchoiceofpartnerwillbeifyouchoosetogodown thispath.Onlypartnerswithdemonstratedskillinvirtualizationwillbeabletoprovide thehelpyouneed.
PREPARETHENETWORKLAYER Now that you have decided how to proceed, you can identify just how your infrastructureneedstochange.Thefirstplacetostartisbylookingatthenetworklayer.As mentionedearlier,you’llneedtodetermineifyournetworkingequipmentisuptothe taskofhandlingtheaddedbandwidthvirtualizationrequires.Ifanythingseemsamiss, replaceit. Then you’ll need to look to your network infrastructure. Virtualization often requiresseveralvirtuallocalareanetworks(VLANs).AVLANisalogicalgroupingof networknodesthatbehaveasiftheywereconnectedtoasinglewireeventhoughthey arelocatedondifferentphysicalLANsegments.IfyouoptedtouseInternetSmallComputerSystemsInterface(iSCSI)forsharedstorageaccess,you’llneedtocreatedifferent
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VLANsforthetrafficthatwillmovefromyourhostserverstoeachsharedstoragecontainer.KeepingeachstoragecontaineronaseparateVLANwillimproveperformance andsimplifytrafficmanagement.VLANsarealsousefulfornetworksegregation—for example,separatingproductionnetworksfromperimeternetworks,separatingserver workloadsfromend-usertraffic,andsoon.Finally,ifyouplantouseliveVMmigration,youshoulddedicateaVLANforthistrafficalone,makingsureyoursystemshave a high-priority bandwidth when they need it most. In fact, you may even choose to dedicateaswitchtothistraffictoensureevenhigherpriorityandsecuritybecauselive dataisbeingtransfered. Youalsoneedtoconsiderthephysicalnetworkidentificationcard(NIC)configuration inyourservers.HostserversoftenhaveaminimumoffourNICs,asfollows:
▼ T woNICsarereservedforserviceconsolesorvirtualmachinemanagement traffic.Serviceconsolesareusedtomanagethevirtualenvironmentand,as such,needhigh-prioritytrafficformanagementpurposes.Thistrafficshould beencryptedatalltimesbecauseitoftencontainsadministrativepasswords andothersensitiveinformation.UsingInternetProtocolSecurity(IPSec)orthe SecureSocketsLayer(SSL)protocoltosecurethistrafficisabestpractice.You useatleastoneseparateNICforthisprocessbecauseitseparatesmanagement trafficfromvirtualmachinetrafficandcanprovideadditionalsecurity.For example,ifyouhaveaVMwebserverthatislocatedinaperimeternetwork andyousharebothwebserverandmanagementtrafficonthesameNIC,itis possiblethattheNICcouldbecompromisedandthenmalicioususerswould haveaccesstomanagementtraffic.YouusetwoNICsforthispurposeto provideredundancyandfurtherisolationofthemanagementtraffic.
■ O neNICisreservedforlivevirtualmachinemigrations.DedicatingaNIC tothistrafficwillprovideitwiththehighpriorityitneeds.ThisNICshould notbesharedwithanyofthevirtualmachinetrafficandshouldbeatleasta 1-gigabyte(GB)NICtoprovidetherequiredthroughput.ThisNICshouldbe assignedtothelivemigrationVLAN.
▲ O neoroftenmoreNICsarereservedforvirtualmachineworkloadsthrough theVMkernel.TheseNICsaresharedbetweenthephysicalhostandvirtual machines.Likeallotherphysicaldevices,networkinterfacecardsareoften underutilizedbyphysicalworkloads.Thismeansthatseveralvirtualmachines cansharethesameNIC.However,youshouldassignatleastonehostNICfor everyfourvirtualmachinesyourunonthehost.Thismaymeanyouwillneed morethanfourNICsperhost.
Inaddition,youshouldassignstaticIPaddressestobothhostsandvirtualmachines asmuchaspossible.InIPversion4(IPv4),thismeansusingoneoftheprivateaddress pools. In IPv6, this means using either globally unique addresses for each server or site-localaddresses,whicharesimilartotheprivateaddresspoolsavailableinIPv4. Ensure that your Domain Name System (DNS) is properly configured for all IP addressing, both virtual and physical. This means both forward and reserve lookups.
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Infact,youmaydeterminethatitisbesttousetwoDNSinfrastructures:aphysical onethatincludesonlyresourcepooladdressesandavirtualonethatincludesallofthe VirtualServiceOfferings(VSO)addresses. Ifvirtualmachinesneedaccesstoorneedtobeaccessedfromremotelocations,you willneedtomakesureyourfirewallsareproperlyconfiguredtoallowthistraffic.Inmost cases,whenorganizationsstartmovingtowardsvirtualization,theyoftenusephysical workstationstoaccessVirtualServiceOfferings.Makesurethefirewallsonalldevices, physicalandvirtual,allowtrafficinappropriatepatterns. NICteaming—ortheaggregationofmultipleNICstoprovidefaulttolerance,added bandwidth,andhighavailability—shouldalsobeconsideredifpossible.Asdiscussed earlier,youshouldalwaysavoidsinglepointsoffailureinyoursystemconfigurations. If you have several VMs sharing a single physical NIC and this NIC breaks for any reason,youwillhaveafailureinseveralworkloads.UsingNICteamingpreventsthis fromhappeningsinceitprovidesdeviceredundancyshouldanymishapoccur.
NetworkinginVirtualLayers Virtual machine technology is designed to support multiple virtual networks within thesamephysicalhost.Forthisreason,youcanactuallyhostvirtualmachinesfromdifferentnetworkzoneswithinthesamehost.Hypervisorsmanagethisprocessbyusing andcreatingvirtualswitchesforeachnetwork.Forexample,inMicrosoftHyper-V,the physicalNICsonahostserveraretransformedintovirtualnetworkswitches(VNS), whichcanthenbeassignedtoseveraldifferentnetworkingmodesinthevirtuallayer (seeFigure5-1).
Figure5-1. NetworkinginHyper-V
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Then,youcanassignvirtualnetworkinterfacestooneofthreeconnectiontypes:
▼ A nExternalVirtualNICwillbelinkedtotheVNStogainaccessbothtothe hostandtotheexternalnetwork.
■ A nInternalVirtualNICwillbelinkedtothehostandwillalsoalloweach ofthevirtualmachinestiedtothisNICtocommunicatewitheachother.No externalcommunicationsaresupported.
▲ A PrivateVirtualNICwilllinkvirtualmachinestothemselvesonlyandwill notprovideanycommunicationstothehostsystem.
TheVNSprocessremovesallsettingsfromthephysicalNICexceptfortheMicrosoft VirtualSwitch.Forthisreasonalone,youshouldhavemorethanoneNICinaphysical host.ManyadministratorsperformhostserverconfigurationsremotelythroughTerminalServices.WhenyoudothisandthereisonlyoneNIConthesystem,allTerminal Servicescommunicationsarelostandthereisnolongeranymeansofcommunicating withthehostremotely.Youmustthensitattheservertocompleteitsconfiguration. UsingatleasttwoNICsinthehostavoidsthisissue. VMwarealsosupportsvirtualnetworkswitches.Forexample,VMwareWorkstation, aSerVproduct,willsupporttenvirtualnetworkswitchesbydefault(seeFigure5-2).Each VNScanbeconfiguredindependentlytoprovidecompleteVMisolation,ifrequired.
Figure5-2. NetworkinginVMwareWorkstation
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When working with hypervisors, you’ll find that you can create as many virtual NICsasarerequiredbyyourVMs.Inaddition,servicessuchasNetworkLoadBalancing(NLB),whichbalancesaworkloadbetweenseveralmachinesbyredirectingtrafficat thenetworklayer,workperfectlywellwithinthevirtualizationlayersoyoucancreate highlyavailableVMconfigurationsbyworkingwiththevirtualnetworkingcapabilities ofthehostserver.MostvirtualizationenginesalsosupportNetworkAddressTranslation(NAT)toprovideaccesstomultipleVMsthroughonesinglephysicalIPaddress. Forthisreason,thesevirtualizationenginesoftenincludetheabilitytoprovideDynamic HostConfigurationProtocol(DHCP)servicestoVMs. Youshouldmakeapointofcarefullydocumentingthevirtualnetworksyoucreate throughtheuseofvirtualnetworkswitchesonyourhostservers.
PREPARESTORAGE Storageconfigurationsshouldbesharedamongthehostsystemsasmuchaspossible. If this is not possible—for example, if you opt to create a low-cost host configuration relyingondirectattachedstorage—youmustimplementareplicationservicebetween hostsinordertosupporthighavailabilityofthevirtualmachines.Thisconfigurationis oftenbestforsmallshopsthatwillonlyrunafewhosts.WindowsServer2008Hyper-V, forexample,becauseitispartofWindowsServer,supportsthistypeofhighlyavailable configurationthroughfailoverclustering,usingamajoritynodesettocreateacluster that does not share data. It must, however, also rely on a replication system in order toensurethatthecontentsofeachnodeintheclusterbeidentical.Whiletechnologies such as Exchange Server 2007 and SQL Server 2008 offer this replication mechanism throughlogshipping—thegenerationofacopyofeachdatabasetransactionlogonlocal aswellasremotesystems,keepingdatabasesinsync—Hyper-Vdoesnot;atleastnot yet. Microsoft, however, does provide a list of replication partners that are supported intheseconfigurationsatwww.microsoft.com/windowsserver2008/en/us/clusteringmultisite.aspx.ThisstrategyisbasedonthemultisiteclusteringcapabilitiesofWindows Server,butinthiscase,eachnodecaneitherbeinthesameordifferentsites,depending onyourrequirement. Themultisiteclusteringconfigurationisonethatwillbeusedeitherbysmallshops orbylargeshopsrequiringmultisiteredundancyfortheirVMs.Mostotherorganizationswillrelyonsharedstorage—eithernetworkattachedstorage(NAS)orstoragearea networks(SAN)—toconfigurehighavailabilityfortheirhostservers.Inthisconfiguration,eachhostserverisattachedtooneormoresharedlogicalunits(LUN)ofstorage (seeFigure5-3).Byprovidingconnectionstomultiplehosts,thesharedstoragecontainer cansupporthighavailabilitybecauseahostdoesnotneedtocopythecontentsofthe storage container to gain access to it. Instead, the high-availability technology simply disconnectsthefailinghostandenablestheconnectiontothefailoverhost,providing servicecontinuity.Intheseconfigurations,allhostsinaserverpoolmustbeconnected tothesamestoragecontainer.
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Figure5-3. Highlyavailableconfigurationsrequiremultipleconnectionstothesamestoragecontainer.
NOTE High availability does not work the same way as live machine migration. Live migration copies the in-memory contents of aVM from one host to another and then activates it, causing nobreakinservice.Thistechnologyisusedtomovemachinestonewhostsinordertoprovidea maximumnumberofresourcestotheVM.Highavailability,ontheotherhand,isusedwhenahost serverfails.Becausethereisafailure,thereisaslightinterruptionofservicebetweenthefailure andthefailover.
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WhilehighavailabilityisprovidedthroughclusteringservicesinWindowsServer 2008Hyper-VandotherhypervisorsbasedontheLinuxXencode,itisprovidedthrough two technologies in VMware: the High Availability (HA) component and the Virtual MachineFileSystem(VMFS).VMFS,especially,isusedtomanageanycontainerthatwill hostvirtualmachinefiles.OneofthefeaturesofVMFSistobeabletosharecontainer connectionswithmultiplehostserversinanHApool.Thismeansthatanysystemtied toasharedstoragecontainercanbethehostofanotherhost’svirtualmachinesincase ofahardwarefailureofsomekind(seeFigure5-4).HAworksinconjunctionwithVMFS toprovidevirtualmachinefailoverfromonehosttoanotherintheeventofahardware failure(seeFigure5-5).VMFSisatrueclusterfilesystem,whichmakesitanessential partoftheHAconfigurationinanESXServerimplementation. Also,whileothervirtualizationtechnologiesrelyonthefeaturesoftheirhostoperatingsystem(OS)tocreatememoryswapfiles,itisVMFSthatcreatesandmanagesthese filesforVMwarehostservers.VMFSalsostoresallundo,redo,log,andconfiguration filesfortheVMs. Anothercomponentrequirementforvirtualmachinestorageistherequirementfor othermediatypefiles.Whilehostserverscansharetheirphysicaldrives,suchasDVD or floppy drives, through Raw Device Mapping (RDM), running multiple VMs on a hostoften means having to access multiple copies of these devices at the same time.
Figure5-4. VMFSlinksmultiplehostserverstothesamestoragecontainer.
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Figure5-5. VMwareHAworksinconjunctionwithVMFStofail-overVMstoanotherhostincase ofhardwarefailure.
SharingasingleDVDdrivewith20VMswon’twork.Inordertocircumventthisissue, hypervisorshavetheabilitytocreatevirtualdrivesthatemulatebothDVDandfloppy drives.Eachisstoredinanimagefileofsomekind.Forexample,DVDsareoftenstored inISOfileformat(withan.isoextension)andcanbetargeteddirectlytolinktoaVM. Your storage containers will also have to make space for this type of media. In many cases,thisisperformedonaNetworkFileSystem(NFS)storagecontainer.ThisNFScontainerissharedamongmultipleVMsthroughsimplefilesharingservices,whichmeans thatitcaneasilybecentralizedsothatonlyonesuchcontainerneedtobemanagedinthe entiredatacenter.InWindows,thiswouldbeastandardWindowsFileServer.
PrepareStorageConfigurations Sharedstoragemustbeconnectedtothehostserverinsomefashion.IfyoursharedstorageisaNASdevice,yourconnectiontothisdevicewillbethroughnetworkinterface cardssincetheNASdeviceisafilesharingunitthatwillprovidefileservicesineither NFSorstandardWindowsfilesharingformat.However,ifyourdeviceisaSAN,you mustdeterminehowtoconnecttothedevice.
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SANsareusuallyconnectedtohostserversthrougheitheriSCSIorFibreChannel. iSCSIreliesonnetworkinterfacecardstotransformstoragetrafficintonetworktraffic. WhileiSCSIdoesnotofferthesameperformanceonitsownasFibreChanneldoes,itcan approximatetheseperformancelevelsthroughnetworkcardaggregation—addingmultipleNICstotheiSCSIloadtoincreasedatathroughputs.Today,SANsarebeingconfiguredaboutevenlythroughbothmethods.FibreChanneldoesprovidebetterthroughput anddoesnotaddanyloadtothenetwork,butthenumberofhostbusadapters(HBA) that are supported by the virtualization manufacturers is far less than the number of NICstheysupport.Forthisreason,manyoptforiSCSIsotheyhavebetterchoiceswhen itcomestosystemconfigurations.Note,however,thatiSCSImaybeabetterchoicefor smalltomediumorganizationsbecauseofthecost.Largeorganizationswilloftenopt forFibreChannelHBAssincetheycanprovidebetterperformanceinthelongruneven thoughtheycostmoreatfirst. Inaddition,manyorganizationsconfigurehostserverstohavedirectattachedstorageforthehypervisorpartitionaswellasthehostconsole,andthenusesharedstorage tostoreandmaintainallofthevirtualmachinefiles.Thisconfigurationvaries,since today,severalmanufacturersofferhostserverconfigurationsthatalreadyincludethe hypervisoronaninternalUSBdrive,makingthedirectattachedstorage(DAS)configurationunnecessary.However,ifyoufindyoumustuseDASinhostservers,usesolid statedrivesasmuchaspossibletoobtaintheverybestIOPSspeeds. YouwillalsowanttobewaryofthenumberofVMseachstoragecontainerhosts. WhileaLUNcanhostupto100VMs,itmightbebesttomaintainnomorethan32VMs perLUNtoimproveperformance.PerformancewillvarywiththeRandomArrayofInexpensiveDisks(RAID)configurationofthedrives.RAID5isoftenthemostusedRAID typebecauseitprotectsdatawhileprovidingacceptableperformance.Buttoday,RAID 10mayprovidethebestperformancebecauseitbothmirrorsandstripesthedisks,gettingthebestread/writeperformancewhileprotectingalldrivecontents.RAID10ismore costlyinthenumberofdiskdrivesneededtocompletetheconfiguration,butinthelong run,itmayprovidethebeststructureforyoursharedstoragecontainers(seeFigure5-6).
VirtualizeStorage Whenyouworkwithsharedstorage,youwillalsobeworkingwithsharedstoragemanagementtechnologies.Thesetechnologieshavetheabilitytovirtualizestorage,making iteasiertoaccessstoragecontainerswherevertheyarelocated.Basically,virtualstorage technologiestransformphysicalstorageintologicalviews.Insomecases,thissoftware canscanallstorage,DAS,NAS,andSAN,andaggregateittoprovideoneunifiedlogical viewofallstorageinanorganization. Virtualstoragefocusesonthevolume,nottheactualdisks.Itishardware-agnosticso thatitcanworkwithstoragecontainersfrommanyvendorsatonce,lettingyouchoose best-of-breedproducts.Itprovidesacentralconsoleforallstoragemanagement. Virtualstoragetechnologiescanbeacombinationofhardwareandsoftwareorthey canbesoftware-only,whichprovidesthemostflexibility.Storagecontainersarepolicybasedandcanbeturnedonasneeded.Butthebestfeatureofvirtualstorageis“thin provisioning.”
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Figure5-6. WorkingwithdifferentRAIDtypes
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When you create a virtual hard disk drive, you’ll find that one of the formats is a dynamicallyexpandingdisk—adiskthatisconfiguredtoamaximumsizebutthatonly storestheactualcontentsofadriveandgrowswithusage.Forexample,youmightcreate a100-GBvirtualdiskdrive,butsincetheactualdiskonlycontains10GB,thefilesizeis only10GB.Thisfilewillgrowto100GBwithusageandmayneveractuallygainthefull sizeoftheconfigureddrive. Thinprovisioningdoesexactlythesamethingforphysicalstorage(seeFigure5-7). Itcreatesastoragevolumeofagivensize,butprovisionsitwithonlythedisksrequired tocontainitsactualsize.Forexample,youcouldconfigureavolumecontainingvirtual machinesto500GB,butifthetotalsizeoftheVMsisonly60GB,youonlyneed60GBof physicaldiskspace.Additionaldisksarerequestedbythestoragevirtualizationtechnology when they are required, saving you enormous costs in actual disks. For this reasonalone,storagevirtualizationisaboontoallshopswantingtomovetoavirtual infrastructure. Inaddition,storagevirtualizationsoftwarewillletyouconfigureRAIDtypeatthe creationofavolume,butwillalsoletyouchangeitwithtime.Thissoftwarewillhelp youmaximizeactualstoragewhilegivingyouthebestmanagementcapabilities.
Figure5-7. Usingthinprovisioningletsyoucreatesharedvolumeswithfeweractualdisks.
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CreateaBackupPlan Thefinalelementinyourstorageconfigurationshouldbefocusedonbackupanddrive replication.BackupiscoveredindepthinChapter14,butitshouldbeconsideredwhen preparingstorage.Afterall,themostimportantmottoinvirtualizationistoavoidsingle pointsoffailure.Ifyouhaveseveralhostserverstiedtosharedstorageinahighlyavailable configuration but you have no protection for the storage LUNs, you will have a singlepointoffailure. MostSANswillincludetheabilitytotakefullLUNsnapshotsduringoperationto protectthecontentsofthedrivestheycontain.Inmostcasesaswell,SANswillbeable to create up to 512 snapshots of their contents, then rely on these snapshots to create backupsofthediskinordertoavoidanyperformanceimpactontheproductiondisks. Youwillneedtodetermineifthisisenough,orifyoualsorequiresomeformofSAN replicationtoanothersite. Basically,theneedsofyourorganization,theimportanceofthedatabeingprotected, andthebudgetofyourprojectwillhelpyoudetermineexactlywhichstrategytouse. Keepinmindthatdataprotectionisoneofthemostimportantaspectsofstoragepreparationinanydatacenter.
Best-in-BreedStorage Therearemany,manystoragemanufacturers,asthereareformosteverytypeofserver hardware.However,NetApp(www.netapp.com)mightbeyourbestbetifyoudonot haveanythinginplaceyet.NetAppdeservesthisrecommendationforthreekeyreasons inregardstovirtualization.
▼ N etAppstoragedevicesallusethesamemanagementinterface.Youcanbegin withthesmallestdeviceNetApphasavailable,learnitsmanagementinterface, andthenneverhavetorelearnhowtomanageNetAppstorageagain,even whenyougettoenterprise-classdevices.
■ N etAppstorageprovidesautomaticlivededuplicationofallvirtualmachines. Ifyourstoragecontainerishosting15WindowsServer2008virtualmachines, NetAppwillautomaticallydeduplicatealloftheircontents.Sinceall15machines usethesamecorefilesfortheOS,NetAppwillstoreonlyonesinglecopyof thesefiles.NetAppwilldothesameforLinuxoranyothervirtualmachine.This cansavemorethan40percentofallstoragecosts.Othertechnologiesprovide deduplicationservicesatthebackuplevel,notatthelivestoragelevel.
▲ N etAppprovidesthebest-in-classreplicationtechnologies.Thisisbecauseit doesnotreplicatethecontentsofthedrive.Instead,itcreatesastoragemap atthebytelevelofonestoragecontainer,shipsthismaptoanother,possibly remote,storagecontainer,andthenproceedstomodifytheremotestorage tomeetthecontentsofthemap.Itcandothisonawiderangeofschedules toensurethatyourdrivecontentsarealwaysthesame.Othertechnologies replicatecontentsonabyte-per-bytebasis,constantlyshippingbytecontents fromonelocationtoanother.
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NetAppoffersthesefeaturesbydefaultandstillprovidesacompetitiveprice/performanceratio.Forthesereasons,youshouldtakethetimetolookatNetAppproductsif youdonothaveasharedstoragecontainerinplaceyet.RelyonNetApprepresentatives tomakesureyouobtainproductsthatincludeallofthefeaturesyouneedforvirtualizationsupport.
PREPAREHOSTSERVERS Whenyoupreparehostservers,mostofyouwillhaveonemajorthoughtinmind:How doIrecoverexistinghardwareequipmentandreuseittoreducethecostofmyproject? Thistopichasbeendiscussedatlengthtodate,butherearesomeadditionalcaveats:
▼ F irst,you’llneedtodetermineifyourserverscanhostvirtualmachines,which theymostlikelycan,butcantheydoitwiththeproperconfiguration?
▲ T hekeytohostserversisresources—processor,memory,network,anddisk. Doyourexistingserversofferthesecapabilities?Considerthefollowing:
■ T hebesthostserverisonewiththemostprocessorsorprocessorcores.If yourexistingserversaredual-coreserversrunningonAMDprocessors, you’reinluck,becauseyoucansimplyreplacethedual-coreprocessors withAMD’squad-coreprocessorswithouttheneedforadapterkits. Simplypopouttheoldprocessorandpopinthenewone.Thisshouldgive extralifetoyourservers.Intelprocessorsdonotswapaseasily,soifyour processorsareIntel,you’llneedtomakeadecision.
■ T hebesthostserversusethesameprocessorswithsimilarstepping tosupportlivemigrations.Ifyouhaveseveralserverswiththese characteristics,retainthem.
■ T hebesthostserverisonewithtonsofRAM.Ifyourserversincludealotof freememorybanks,fillthemupandreusethesystem.
■ T hebesthostserverincludeslotsofNICs.Ifyouhaveavailableslotsand youcanaddNICstotheserver,thendoso.
■ T hebesthostserverwillrelyonsharedstoragetostoreVMs.Ifyoucan eitheraddNICsinsupportofiSCSIorhostbusadapterstoyourservers, thenretainthem.
Basically,ifyoucanaddtoyourserverconfigurationsand,atthesametime,tiethem intohigh-availabilityconfigurationssuchasclusterconfigurations,youcanretainyour serversandreusethemashosts. Youalsoneedtodetermineifyouwillscaleuporscaleoutyourhostsystems.Scalingupimpliestheuseoffewer,larger-capacityservers,eitherrack-mountedortower, butmostlyrack-mounted.Scalingoutimpliesusingmore,smallerserversthatareeither rack-mounted or blade systems. While this question was often moot for application serversbecausemanyapplicationscouldnottakeadvantageofthemultipleprocessors
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Figure5-8. Clustermembersmusthaveenoughspareresourcestosupportdowntimeforeach oftheirpartners.
orprocessorcoresscale-upsystemsoffered,withvirtualization,thenatureofthegame changesbecausehostserversaredesignedtousealloftheresourcesofasystem.Therefore,itishighlypossibletoscaleupwithvirtualization. However,youmusttakeintoaccounthostservermaintenance.Largerserverswill hostmoreVMs,andifyouneedtoshutdownthelargersystem,youcouldhavepotential outages. Keep in mind that each time you create a monster server to host dozens ormoreVMs,youalsohavetocreateitstwinsinceyouneedtocreatehighlyavailable configurations.Becauseofthis,youalwaysneedtocreatehostserverconfigurationsthat haveavailableresourcestohosttheirpartnerserver’sworkload.Iffourserversareina cluster,eachservermusthaveenoughresourcestohostalloftheVMsoftheirpartners (seeFigure5-8).Whenyoudecidetoscaleup,theseserverconfigurationscanbecome expensive. However,youcanusearuleofthumbtoreducetheserverconfigurationwhenyou scaleup.Forexample,ifyouassumethatinasix-nodecluster,onlytwonodeswillfail atthesametime,youcanhostmoreVMsoneachhostandensurethatyoualwayshave enoughresourcestocoverthesefailuresintheothernodesofthecluster.Thisruleof thumbwillnotcoveracompleteclusterfailure,butitwillletyoucreatelessexpensive scale-upclustersandwastefewerresources. Butbecausescaled-upclusterscanbemorecomplextocreate,itmightbebesttoscale out,usingsmallerbladeserversthatcaneasilybeconfiguredtosupporttheirpairnodes in cluster configurations. Blade servers are so much easier to obtain and put in place oncetheirenclosuresaresetup,thatscalingoutbecomesasimplestrategytosupport.In fact,theverybesthostserverseemstobeonethatincludesaminimumoftwoquad-core CPUs,atleast32GBofRAM,atleastfourNICs(possiblyteamed),andnointernaldisks (seeFigure5-9).Thesystemeitherrunsfromaninternalintegratedhypervisororitboots fromtheSAN,avoidingtherequirementforDASdisks. Whileperformingtheirownvirtualizationproject,processormanufacturerInteldiscoveredthatmostapplicationscanoperatewithasingleGBofRAMwhenvirtualized.
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Figure5-9. Theidealhostserverconfiguration
Outof3,000serversintheiranalysis,morethan1,500onlyused1GBorless.Thisincludedmostlyfileservers,webservers,andbackupsystems.Insomecases,theyfound thatcertaine-mailanddatabaseserversalsohadlowRAMutilization.Theyalsofound that2-GBDualInlineMemoryModules(DIMMs)providedthebestdollar/RAMvalue. However,sincethisstudywasperformedduringtheirownproject,whichoccurredin late2007,itmightbebettertooptfor4-GBDIMMstoday. Intheend,you’lldeterminewhichisbestforyou.Ifyouhavethousandsofmachines tovirtualize,scalingupisthebestoptiontomaximizehostserverworkloads;however, ifyouonlyhaveafewVMstocreate,scalingoutisthebestoptionsincesmallerservers offerabetterprice/performanceratioandaremucheasiertointroduceandreplace. Whenyoulooktoyourownexistingservers,you’llprobablyfindthefollowing:
▼ T owerserverswillmostlikelyberetainedonlyfortestanddevelopment environmentssincetheydonotneedtosupporthighlyavailable configurations.
■ T owerserverswillalsoberetainedbysmallershopsthatonlyhaveafew workloadstovirtualize.
■ R ack-mountedserversmaybeadaptedtosupportvirtualization,butwill mostlyrequireupgradedcomponents.
■ Bladeserverscanalsobeadaptedtosupportvirtualization.
▲ E xistingclustersrunninge-mailordatabasescanbetransformedintohost serverclustersandcanactuallyformthesourceofyourhostclusterpool. However,youmustbecarefulwhenyouconverttheircurrentworkloadsto virtualization.
Whateveryoudowithexistingsystems,makesureyouconfigureyourhostserversin suchawaythatyouwillnothavetoreplaceorupgradethemintheshortterm.
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NOTE Rememberthatifyouneedtodisposeofyourservers,Chapter1pointedoutgreendisposal resources,oneofwhichwaswww.GreenAssetDisposal.com.
ServerSizingforResourcePools Ifyouopttousenewservers,youwon’tinstallserversthatmeetminimumrequirements. Infact,ifyou’replanningonputtingtogetherahostservernetwork,yourserverswon’t beatthebaserecommendation,butwillbesizedtomeetoptimumworkloads.Thisis donebyperformingaformalserver-sizingexercise.Thisexercisewillhelpyoudetermine thehardwareconfigurationsforeachofyourhostservers.Itwilltellyouwhatsizeyour server should be, where it is needed, and what it should deliver in terms of services. Whenperformingaserver-sizingexercise,takethefollowingitemsintoconsideration:
▼ Identifyserverbases Relyonthefeaturesofthehypervisoryouselect(see Chapter7)toidentifywhereyourVMgroupingswillbe,howmanyVMsyou willrunoneachhost,howyouwillteamhostsforhighavailability,andhow manyhostserverswillbeinateam.Youwillneedtopositionyourservers whereyouhaveaconcentrationofVMs.Thiscanmostlybeincentraloffices sincevirtualizationalsosupportsservicecentralization.
■ N umberofguestoperatingsystemsperserver Identifyamaximumnumber ofguestoperatingsystemsperhostserver.Toprovideagivenlevelofservice, youneedtoensurethattherearenevermorethanaspecificnumberofguests, dependingonthisserver’sresources.Onaverage,organizationsrunbetween 10and30virtualmachinesperhost. TIP Rememberthatallphysicalhostsmustbe64-bitserversifyouwanttorunHyper-Vonthem. Ifyouwanttoreuse32-bitserversashosts,youcandoso,butyouwillneedtoruneitherMicrosoft VirtualServerorVMwareServerontopofa32-bitversionofanOStoprovidevirtualizationservices. Youcanalsouse32-bitdevicestorunVMwareESXServersinceitisbasedon32-bitcode.
■ M aximumacceptableserverload Determinethespeedofresponseyou wantfromaserverwhenprovidingservices.Forhostservers,thisloadmust takeintoconsiderationthemaximumcentralprocessingunit(CPU)usage. Usually,CPUandRAMarethemajorbottlenecks.Learntoavoidthem.One goodwaytodothisistocontinuallymonitorCPUandinputandoutput(I/O) performanceontheserver.
■ S ervervariance Thelocationoftheserverisalsoimportanttoconsider becauseitoftenservestodeterminethenatureoftheserver.Mosthostservers arelocatedincentraldatacenters,butinsomecases,youwillwanttodeliver localservicestoremoteoffices.Thevirtualdatacenterwillruntwohost machineswithsharedstorage(ifpossible)inregionsandruntheappropriate numberofguestoperatingsystemstomeetdemand.
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■ M inimumservercapacity Determinetheminimumhardwarecapacityyou wantforyourhostservers.Rememberthatyoudon’twanttochangethemfor sometime.Thepurposeofyournetworkistodeliverhigh-qualityservicesto youruserbase.Takethisintoconsiderationwhenyoudeterminetheminimum servercapacity.Capacityplanningshouldidentifyitemssuchasnumberand sizeoftheprocessors,amountofRAM,anddisksize.
■ M ultiprocessingandmulticore Youshouldusemultiprocessingservers (serversthathavemorethanasingleprocessor)aswellasmulticoreprocessors (processorsthathavemorethanoneCPUcore)forhostservers.Infact,right now,youshouldincludeatleasttwoquad-coreprocessorsineachhost.Ifthey canincludemore,thendoso.Inashorttime,we’llhaveaccesstoocto-core processorsandmore.
■ R AMsizing Theruleissimple:ThemoreRAMyouhave,thebetteryour serverwillperform.Thus,RAMisnotaplaceyoushouldskimpon,especially forhostservers.Hostserversshouldstartwithaminimumof16GBofRAM, butmanyorganizationsgostraightto64-GBconfigurations.Keepinmind thattheRAMsizewillaffectthepagingfile.Thebestruleofthumbhereisto startthepagingfileatdoublethesizeofyourRAMandsetitsmaximumsize tofourtimesthesizeofRAM.Thisrulemeansthatyou’llneedtoreservea minimumandmaximumamountofdiskspaceforthepagingfile. NOTE ThisswapfilerulemostlyappliestoMicrosoftHyper-V.WithVMwareESXServer,theswap fileisusedbytheconsoleOSandis544megabytes(MB)bydefault,regardlessofthephysicalRAM inthesystem.Buttooptimizeperformance,manydeploymentsuseanESXswapfileof1600MBor twotimesthemaximumserviceconsolememorywhichis800MB.Allotherpagingisper-VMandis coordinatedbytheVMwarememoryballoondriver.
■ D isksizing Thesizeandnumberofdisksyouattachtoeachserverwill dependonanumberoffactors.Howmanypartitionsdoyouwantto make?Howmuchspacedoyouwanttoreservefortheoperatingsystem, programs,andspecialelementssuchasthepagingfile?Howmuchspacefor datastorage?Doyouwanttousedirectattachedstorageorremotestorage? Whateveryouchoose,mostserverswillendupwiththree,perhapsmore, partitions:oneforthemanufacturer’sserverutilities,onefortheoperating systemandprograms,andonefordata.
orhostservers,datapartitionsshouldalwaysbeonshareddisksand F beseparatefromsystempartitions.Inaddition,datapartitionsareoften significantlylarger.Shareddiskswillallowyoutorunthehypervisor,ifit isn’tembeddedinyourserver’shardware,aswellasdatadrives.Inaddition, shareddiskswillletyouimplementhigh-availabilitystrategiestomakesure thatyourVirtualServiceOfferingsarealwaysavailable.
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■ H ardwareprotection Allofthisdataneedssomelevelofprotection.Local diskdrivesshouldbeprotectedbyRAID.Asmentionedearlier,manypeople optforadiskmirroringsystem(RAID1)forthesystemdrives,andstripesets withparity(RAID5)ormirroredstripesets(RAID10)fordatapartitions.
■ S toragestrategy Thehardwareprotectionsystemyouchoosewillalso dependonyourstoragestrategy.Hostserversshouldsharedrives.Many manufacturersaredeliveringinnovativeall-in-oneboxesthatincludetwohost serverswithsharedstorage,allinaconvenientcoolingcasingforregional networks.Forcentralservers,youshouldimplementsharedstoragebasedon yourorganizationalneeds.Smalltomediumorganizationswilloftenoptfor DASwithreplicationorNASdevices,whereaslargerorganizationswillneed SANs.Hypervisorswillworkwithseveraldifferenttypesofsharedstorage; justmakesureyouselectsomethingthatisonthehardwarecompatibilitylist (HCL)yourhypervisorproviderpublishes.
■ P hysicallocation Thephysicallocation,theactualphysicalspacetheserver willoccupy,willhelpyoudeterminewhetheryouwillchoosearack-mounted ortowerserverconfiguration.Inmostcases,regionalserversaretowerservers andcentralizedserversarerack-mountedbecausetheyareconcentratedina singlephysicalspace.Ifyouoptforrack-mountedservers,considertheblade serversinstead.Asmentionedearlier,theyareperfectforscalingouthosts.In addition,bladeserversoffermuchmorecompactfootprints,oftensavingas muchas70percentofrackspace,50percentpowerconsumption,80percent cabling,and20percentheatgenerationcomparedtootherrack-mounted servers.Remember,yourphysicallocationshouldbelockableandoffer temperaturecontrols.
■ B ackupmethod Onceagain,thephysicallocationoftheserverwillhelp determinethebackupmethodselected.Regionalserversoftenusedtape drivesforbackup.Dependingonthespeedandavailablebandwidthofyour wideareanetwork(WAN)connection,youmightjustbackupalldatato acentrallocation.MoreonthistopicwillbecoveredwhendiscussingVM protectionstrategies.
▲ Growthpotential Youdon’twanttobereplacingthissystemsixmonths afteryouputitinplace,somakesureithasacapacityforgrowth.Allsystems shouldhavetheabilitytoaddmoreprocessorsoratleastreplacethem,more memory,andmorediskspace.Assuch,you’llneedtoconsidertheserverlife expectancy—whentheserverwasintroducedbythemanufacturer,whenit willberetired,whatitsprojectedgrowthpotentialbythemanufactureris,and soon.Ifyouplancarefully,you’llbeabletoimplementserverswitharichlife cyclethatmeetyourexpectations.Insomeconditions,thislifecyclecanlastup tofiveyearsormore.
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Thisexercisehelpsyouidentifythegenericsizeofeachserver.Severalmanufacturers suchasDell,HP,andIBMoffersizingtoolsforhostserversontheirrespectiveWebsites. Relyonthesetoolstocreateyourbesthostserverconfiguration.
SizingRecommendationsforResourcePools Youalreadyknowthathostserversshouldbe64-bitsystemsusingsharedstorage.They shouldalsobebladeservers,ifpossible,becausebladescanbeimplementedfasterthan otherservertypesoncethecasinghasbeenconfigured.Theyshouldincludemultiple NICssothattheywillprovidesufficientthroughputforthemultipleVMstheywillrun. TheOSshouldbestoredonthesharedstorageorwithinthehosthardware,asthiswill facilitateprovisioning.Data—thestoragespacefortheVMs—shouldbeonsharedstorageandshouldformthebulkofthediskspaceallocatedtothisserver.Anothersmaller partition should be used to store the snapshots that will be required to back up the virtualmachines. Table5-1outlineshardwarerecommendationsforhostservers.
Components
Recommendation
CPU
3GHzormore
CPUarchitecture
X64
Minimumnumberofquad-coreCPUs
2
MinimumRAM
32GB,64GBrecommended
Hypervisor
Built-inoronsharedstorage (remoteboot)
Hypervisorconfiguration
ClusteredforHA
Datadiskconfiguration
Twodrivesinsharedstorage:bulk fordataandsmallpartitionfor snapshotbackups
Sharedstorageconnection
iSCSI
NICs
Minimumoffour,withatleast 1-GBspeed
Servertype
Bladeorsmallformfactor rack-mountedserver
Table5-1. SizingRecommendationsforHostServers
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UpgradingHostServers Asyoumovetothedynamicdatacenter,you’llrealizethatyouwon’tberunning upgradesonthehostservers.Eachhostserverwillmostlikelybeanewinstallation.Then,theserviceofferingsthatwillnowbevirtualizedcanundergoeitherupgradesornewinstallations.Wewouldarguefornewinstallationsatalltimes,but thatisobviouslyyourchoice.Rememberthatbeforeyoucanperformanupgrade onanexistingsystem,youwillneedtoconvertitfromaphysicaltoavirtual(P2V) installation.BothMicrosoftandVMwareofferP2Vtools,asdoothers.Microsoft’s bestP2VtoolisfoundinSystemCenterVirtualMachineManager(VMM).InformationonVMMcanbefoundatwww.microsoft.com/systemcenter/scvmm/default .mspx.VMwareoffersVMwareConverter,agraphicaltoolthatconvertsphysical machinestovirtualversionsandalsoconvertsmachinesbetweenvirtualformats. Converter is free and can be found at www.vmware.com/products/converter. Ofcourse,ifyouownVMware’sVirtualInfrastructure,youwillalreadyhavethe Enterprise version of Converter, which allows you to capture running machines and virtualize them. VMware Converter will also convert virtual machine disk formats,forexample,fromMicrosoft’sVHDtoVMware’sVMDK.Moreinformationcanbefoundathttp://vmtoolkit.com/files/folders/converters/entry8.aspx. There are also third-party P2V tools, such as those offered by PlateSpin (www .platespin.com),thatoffermuchmorefunctionality.MoreonP2Vwillbecovered inChapter9.
RelyonHardware-IntegratedHypervisors VMwarewasthefirsttomakeitshypervisoravailabledirectlywithinserverhardware. VMwareESXiisasmall32-MBhypervisorthatisloadedontoaninternalUSBthumb drivelocatedwithintheserverhardware.Becauseofthis,itiseasytoaddanewhost servertoyourresourcepool.Usethefollowingprocess:
1. Mounttheserverwithinarackorbladeenclosure.
2. Poweriton.Theserverautomaticallybootsintothehypervisor.
3. Configuretheadministrativepasswordtosecurethesystem(seeFigure5-10).
4. ConfigureastaticIPaddressforthehostserver(seeFigure5-11).
5. C onnecttheclienttothevirtualinfrastructurethroughthemanagement console(seeFigure5-12).
Asyoucansee,thisprocessiseasytoimplement.Addinghostserversisasnap,especially nowthatESXiisavailableforfree.
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Figure5-11. ConfiguringastaticIPaddressinVMwareESXi
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Figure5-12. AddingaVMwareESXitoamanagedinfrastructure
VMwareisnottheonlyvendorthatcreatesbuilt-inhardware/hypervisorconfigurations.Citrixalsooffersanoriginalequipmentmanufacturer(OEM)versionofXenServer, andMicrosoftoffersacustombuilt-inversionofHyper-Vwithcertainhardwareconfigurations.EachisaseasyandsimpletoimplementasESXi.Forthisreason,youshould considerobtainingsystemswithpreconfiguredhypervisors. CAUTION If you download and install VMware ESXi, Citrix XenServer Express, or Microsoft WindowsHyper-VServer(notWindowsServer2008withHyper-V)onyourownhardware,youwill notgainaccesstothecompletehypervisorvirtualizationfeatureset.VMwareESXiwillrequirethe purchaseandadditionofoneoftheeditionsofVMware’sVirtualInfrastructureinordertogainamore completefeatureset.XenServerExpresswillneedtobereplacedbyanothereditionofXenServer inordertogainsupportforthemanagementofmultiplehostserversthroughasingleinterface.And MicrosoftWindowsHyper-VServerwillneedtobereplacedbyeithertheEnterpriseorDatacenter Editions ofWindows Server 2008 with Hyper-V in order to gain access to features such as high availability.
BuildYourOwnHypervisorHardware However,youmaynotalwaysbeabletoinstallbrand-newserversthatalreadyinclude the hypervisor. For this reason, you need to create standard host server installations.
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Creating a VM is easy. Just copy the files of one VM, rename them, repersonalize the server,andyou’reoff.Butcreatingahostserverismorecomplexbecauseitisbasedon hardware. One of the best ways to do this is to use boot-from-SAN operating system partitions.BybootingfromtheSAN,youdonotneedanydirectattacheddisksonthe serveryouimplementanditiseasiertotreattheOSpartitioninmuchthesamewayas youwouldtreatavirtualdisk.ThisisbecauseSANshavetheabilitytocreatesnapshots ofdiskconfigurationsandduplicatethem,muchinthesamewayasyouwouldsimply copyavirtualharddiskdrive.IfyouhavethemeanstobootfromSAN,usethefollowingprocesstobuildhostservers:
1. CreatethehostOSonsharedstorage.
2. CopyatleastoneLUNthatcontainsahostOS.
3. A ttachthisLUNtoahostserveranddepersonalizeit.ForWindowshost servers,thismeansrunningtheSysPrepcommandonit.SysPrepwillremove theservername,removethesystem’sgloballyuniqueidentifier(GUID),and removethesystem’ssecurityID(SID).ForLinuxhosts,you’llhavetoruna customscripttodothesame.
4. DetachthisLUNfromthehost.
5. E achtimeyouneedtocreateanewhost,createacopyofthisLUNandattach ittothenewhost.Bootthesystemandrepersonalizeit.
Asyoucansee,thisprocessismuchfasterthanusinganyothermeanstocreateahost partitiononaphysicalserver. Ifyoudon’thaveaccesstoaSAN,you’llneedtocreateastandardsetupforyour serversandpossiblyrelyondiskimagestoreproduceitonanyotherhostserveryou needtocreate. NOTE ForinformationonhowtocreateVMwareinstallations,gotowww.vmware.com/support/ pubs/vi_pages/vi_pubs_35u2.html. For information on creating XenServer hosts, go to http:// docs.xensource.com/XenServer/4.0.1/installation/installation.html.ForHyper-Vinstallationsgoto www.microsoft.com/windowsserver2008/en/us/hyperv-install.aspx.
THENEXTSTEP Most organizations begin using virtualization in support of testing and development beforetheymoveitintoproduction.Thisisgoodpracticesinceitletsyoubecomefamiliar with the virtualization infrastructure in environments that do not require the same type of service level agreements as production does. For this reason, the next chapter focusesonhowtoprepareyourvirtualizationenvironmentinalaboratory.Oncethisis complete,youwillbemorepreparedtomovevirtualizationintoproduction.
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syoupreparetomoveforwardwiththepreparationofyourhostservers,you needtobeginworkingwithvirtualizationtechnologiesinordertomastertheir controlbeforeyoubeginthephysicaltovirtual(P2V)processthatwilltransform your production workloads into virtual machines. The best place to start is with the laboratory.Laboratoriesconsistofworkloadsthatareinconstantflux.Machinesneedto bereprovisioned,systemsneedtobereconfigured,andentireenvironmentsneedtobe torndownandrebuiltonaregularbasis.Whilethisisanarduoustaskinthephysical world,itbecomesasnapinthevirtualworld.Vendorsevenprovidedifferenttechnologies thatfacilitatelabmanagementevenmorethanthevirtualizationenginedoes,lettingyou build,use,andteardownentirevirtualenvironmentsinonefellswoop. Youbeginwiththetestinglaboratorybecauseitisperhapsthemostimportantpartof anytechnicalimplementationproject.Testingandretestingsolutionsbeforetheyaredeployedistheonlywaytoensurehighqualityandavoidproblems.Afterall,youdonot wanttofindyourselfinasituationwhereyouaredeployinggarbageintoyournetwork. Garbageaside,you’llquicklyfindthatthelabenvironmentisoneofthemostexciting aspectsoftheproject.Thingsmovefast,you’replayingwithnewtechnologies,you’re thehubofalltechnologicalrequests;it’sjustfuntoworkinthelab.Thisisanotherreason whyyouwanttohaveeverythinginplacetherightway. Whetheritisfortraining,testing,ordevelopment,it’sreallyhandytohaveareadily availableworkingenvironmentyoucanjustjumpintowithinminutes.That’swhyyou needavirtuallaboratory.Thislaboratorywillthenbecomethesourceofallofyourvirtualizationeffortsandwillletyoumaintainacomprehensivetestingenvironmentwhen yourprojectisdone. But for virtual laboratories to provide this kind of support to any IT project, they needtobetreatedasofficialsystemsthathavetheirownplaceintheproductionnetwork.Thisiswhyyouneedastructuredandstandardapproachfortheircreation.That’s whatthissectionisallabout:howtobuildavirtuallaboratory,setitup,useandreuse it,andmanageitforlong-termoperation.Thestrategiesoutlinedinthispartstemfrom real-worldprojectsthatcoverallsortsofusagescenarios.Thesestrategieswillhelpyou obtainvaluefromyourlaboratoryandensureyougetasolidreturnoninvestment(ROI) fromyourefforts.Forexample,onecustomerwasabletobuildanentirecollaboration testingenvironmentinlessthan32hours.Thinkofit:lessthanfourdaystobuildthree physicalhostsandmorethantenvirtualmachinesplayingdifferentroles.Inaddition, thecustomerwasabletoreusethisenvironmentforothertestingpurposes.Andthiswas thefirsttimetheyusedavirtuallaboratory!Thereisnodoubt:thislevelofROIissimply notavailablewithphysicallaboratoryenvironments. Whenyou’rebuildingalaboratory,anylaboratory,youneedtofocusonfourdifferentareas.
▼ LaboratoryDescription Thefirstdealswiththeneedtooutlinethestrategy youwillusetocreateandimplementtheenvironment.
■ L aboratoryDeliverables Thesecondhelpsidentifyhowthedeliverablesfrom thelaboratorycanbeusedinsupportofothertestingordevelopmentscenarios.
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Withvirtuallaboratoriesinparticular,it’sreallyeasytoincludepreconstructed machinesasdeliverablestootherprojects.That’sbecausevirtualmachines (VMs)arereallyonlyconstructedofafewfilesonadisk—largefilesadmittedly, butfilesthatcanbetransported,copied,ordownloadedfromremotelocations.
■ L aboratoryManagementPractices Thethirdneedstofocusonthepractices you’regoingtouseforthemanagementandoperationofthelaboratory.Once again,filemanagementwillbeabigpartofthisactivity.
▲ FuturePlansandProjectedGrowth Thefourthlooksbeyondtheimmediate andcoversbothbestpracticesandrecommendationsforfuturelabusage, aswellasthecreationandmanagementofadistributedvirtuallaboratory structure,asmoreandmoremembersoftheorganizationrequireaccessto runningtechnologies.
Thesefourpillarswillhelpyoubuildandprepareavirtuallaboratorythatcanbeused tosupportanynumberofscenarios,suchas:
▼ EnterpriseDevelopmentEnvironment Developersneedtohaveacertain amountoffreedomonthemachinestheyworkwith,butsincethesemachines areenterprisesystems,theymustbecontrolled.Withinavirtualenvironment, theycanbegrantedthelevelofprivilegetheyneedwithoutcompromising productionsecurity.
■ T estEnvironment Newtechnologies,newproducts,newpatches,new hotfixes…allneedtobetestedbeforetheyareintroducedintheproduction environment.Avirtuallaboratorycanbeusedtocreatealow-costreproduction oftheproductionenvironmentinsupportofthesetests.Inthiscase,thislab willbeusefultohelpyoubecomefamiliarwithvirtualizationtechnologies andhowtheywork.Lateron,youcanrelyonittotesttheadditionofnew technologiestoyourVirtualServiceOfferings.
■ S upportEnvironment Helpdeskoperatorssupportinglevels1,2,or3can usethevirtualenvironmenttoreproduceanyproblem.Thisavoidshavingto givethemmultiplesystemsandletsthemtestoutmultiplescenarioswithout impactingtheproductionenvironment.
▲ TrainingEnvironment Avirtuallaboratoryistheidealenvironmentfor trainingpreparation.Youcaninstallanytechnologyandsimulatemostany situation,whichletsyougainpracticalexperienceonthetechnologiesyou wanttobecertifiedin.Infact,thevirtuallabwillletyoutestoutscenariosthat yousimplycouldn’treproduceinyourproductionnetwork.
YoumightalreadybeusingtechnologiessuchasVMwareorMicrosoftvirtualization, butthepracticesoutlinedherewillhelpyoumovefromanadhocusageofvirtualmachinestoanofficiallysupportedimplementation,fromwhichmultiplemembersofyour organizationcanprofit.
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WORKWITHDIFFERENTTESTINGLEVELS Testing is performed in a graduated process, which gradually evolves into more and more complicated testing levels. For virtualization and other IT integration projects, therearefivetestinglevels.
▼ Unit
■ Functional
■ Integration
■ Staging
▲ PilotProject
TheUnittestinglevelisdesignedforinformationdiscovery.Itspurposeistoletindividualtechnicalteammembersdiscoverhowthefeaturetheyaretaskedwithdesigning works.Forexample,theteamshouldusethistestingleveltodiscoverhowthecreation ofvirtualmachinesactuallyworks,playwiththevirtualfiles,discoverhowtheoptions ofthevirtualmachinescanbemodified,andgenerallyfamiliarizethemselveswiththe entirevirtualizationprocess. TheFunctionaltestinglevelisdesignedforinitialsolutiontesting.Here,thetechnical teamhasdeterminedjusthowafeatureworksandnowtheywanttotesttheautomation mechanismstheyarepreparing. TheIntegrationtestinglevelstartsbringingeachindividualcomponentofthetechnicalsolutiontogether. TheStagingtestinglevelisfocusedongettingeverythingright.Basically,thislevel willprovideanenvironmentthatissimilartoyourproductionenvironment.Whilein Integration,youblendedeveryaspectofthesolutiontogether;inStaging,youwantto makesureyoucanreproduceeverytechnologicalaspectfromAtoZwithoutahitch. You’llhavetorepeattheprocessuntilitisabsolutelyright.Thisway,you’llknowexactly whattodowhenyoumovetoproductionandyouwon’tmakeanymistakes.Technical implementationsare80percentpreparationand20percentimplementation,butyoucan onlygetthereifyou’vefullytestedeachaspect. ThefinaltestinglevelisthePilotProject.Whilealloftheothertestinglevelsfocused ontechnicaltesting,thePilotProjectfocusesonthecompletesolution,includinganyadministrativeaspectoftheprocess.Thistestwillvalidatethelogisticsofyoursolutionas wellasthetechnicalaspects.Makesureyou’vecompletelyevaluatedeachaspectbefore youmoveon. Thesetestinglevelsrequiregraduationfromonetotheother(seeFigure6-1).Each levelwillhavebothexitandentrycriteria.Forexample,toleavetheUnitlevel,techniciansmustprovethattheyhavecoveredalloftheactivitiesforthislevel.Toenterthe Functionallevel,techniciansmustmeetkeyrequirements,andsoon.You’llbuildyour exitandentrycriteriaasyoulearntoworkmorefullywiththelab;butbasically,they shouldaimtomakesurethattechnicalteamsarefullypreparedtomovefromonelevel toanother.Withthehighdemandyou’llhaveforlabresources,youdon’twantoneteam
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Figure6-1. Thefivedifferenttestinglevels
tohogresourcesbeforethey’rereadytoaccessthem.Also,youwanttomakesurethat nodamageisdonetoanyofthehigh-levelenvironments—forexample,Integrationand Staging—causing you to have to restore them from backup, or worse, re-create them fromscratch.Thelabisfortheuseofalltechnicalteammembersandshouldneverbe monopolizedforonesingleaspectofthetechnicalsolution. NOTE For a view into the integration architecture—the architecture that is used to build and managetestinglevels—aswellasasampleExitCriteriasheet,havealookat“Buildtheintegration architecture”atwww.reso-net.com/articles.asp?m=8#g.Thisarticleispartsixofaseven-partseries onenterprisearchitectures. Thistestingstructureisacceptedindustry-wideandhelpsmanagetheprogression ofasolutionfromstarttofinish.Whenyouperformthesetaskswithvirtualizationsoftware,youmovevirtualmachinesfromonestagetoanother,progressivelyimproving
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Figure6-2. VMwareStageManagerfullysupportsthefivetestinglevels.
thesolutionuntilitisreadyforproduction.Insupportofthisprocess,VMwareoffers StageManager,acoordinatorthatfullysupportsthisprocessthroughautomatedpolicies,providinganadditionalmeasureofcontrolovertheprocess(seeFigure6-2).This isonemoreadvantageofusingvirtualizationinsupportofnewsolutiondevelopment andpreparation.
RELYONVIRTUALMACHINESOFTWARE Virtualmachine(VM)softwareisanidealcomplementtothelaboratory.Therearelots ofreasonswhythisisthecase.Firstofall,youcanvirtualizemostanyserversinyour environment.You’llalsofindthatwhileyouneedtoallocateconsiderableamountsof RAMtoproductionworkloads,laboratoryworkloadscanoftengetbywithmuchless. Forexample,WindowsServer2003workloadscaneasilyrunwithaslittleas256megabytes(MB)ofRAMallocatedtotheVM,whereasWindowsServer2008requiresatleast 512MB.Ofcourse,youmayneedtoincreasetheamountofRAMwhenyouaddmore thanoneroletotheserver,butifyouhavetheappropriatehost,youshouldeasilybeable torunanyserverroleyouneed. WorkingwithbothclientPCsandserversthroughVMswillseriouslycutdownthe costofbuildingthelaboratory.YoucanrelyonvirtualtechnologyfromMicrosoft,Citrix, orVMware,asallofferfreecopiesoftheirtools,onceagainreducinglabcosts.Allthree offerfullsupportforrunningWindowsserversorPCsaswellasanynumberofoperatingsystems(seeChapter7).Youwillalsoneedtoobtaintoolsfortheconversionof physicalmachinestovirtualinstances(seeChapter7again).Thissavesalotoftime,as yousimplypointtothephysicalmachineyouwanttocaptureandeasilytransformit intoavirtualinstance.
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Inaddition,workingwithvirtualmachines,youcan“virtualize”thelaboratory.Many ofourclientsbuysomelargehostmachinestoruntheirlaboratories.Asyoulearnedin Chapter3,theidealmachinewillbeanx64serverrunningseveralmulticoreprocessors, lotsofRAM,andlotsofdiskspace.Inthelab,youmightnotneedsharedstorage.Itall dependsonyourservicelevelagreementsforlaboperations.Useanx64operatingsystem(OS)forthisserver,installthevirtualizationtechnologyyou’vechosen,andyou’re offandrunning.Whenyouconsiderthecostofthesemachinescomparedtothecostof havingacompletephysicallab,theyreallycutdownonyouroverallcosts. Thereareawholeseriesofoperationsyoucanperformwithvirtualmachinesthat you just can’t perform with physical machines. For example, you can easily create a sourcemachine.InstallafirstinstanceoftheOSintoaVM,customizeitsconfiguration, updateitsdefaultuserprofile,updateitintermsofpatches,andonceitisready,copy itanddepersonalizethecopy.Voila!Younowhaveasourcemachinethatcanbecopied andreusedtoseedanymachineroleyouneed.That’saloteasierthanworkingwitha physicalmachine. AnothermajorbenefitistheuseofVolumeShadowCopyService(VSS)onWindows Server 2003 (WS03) or Windows Server 2008 (WS08) if Windows Server is your host OS.Sincevirtualmachinesarenothingmorethanaseriesoffilesonaharddisk,you canenableautomaticbackupprotectionforthembyenablingVSSandthenrelyingon thePreviousVersionsclienttorestoreanydamagedmachinealmostinstantly.VSSautomaticallytakestwosnapshotsperdayandcanstoreupto64differentsnapshots(on WS03)or512snapshots(onWS08),whichprovidesanadequatelevelofprotectionfor yourVMs.Thisdoesn’treplaceproperbackups,butitisatleastafirstlineofdefensethat costslittle,ifanything. NOTE VMwarestartedshippingaVSSWriterinESX3.5Update2,givingESXsimilarsnapshot capabilitiestoHyper-V’s.
PHYSICALVERSUSLOGICALWORKSPACES Another advantage of virtual machine technology in the testing lab is that you don’t needthephysicalspaceaconventionallabusuallyrequires.Ifyoucreatethelabspace inadatacenterbyhostingaseriesofvirtualmachinesonagivensetofservers,thehost serverscaneasilybelocatedinthenormaldatacenterandprofitfromthestandardoperationsappliedtoanyproductionserver—backup,patchupdates,antivirusupdates, andsoon.Then,yourtechnicalteamcanconnecttotheVMstheseservershostthrough thenormalnetwork.Theremaybereasonforyoutoprovideyourteamswithaseparate networksegmenttoisolatetheirnetworktraffic,butifeverythinghappensinthedatacenteronthesameserverhosts,networktrafficisnotreallyanissue.
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DEFINELABREQUIREMENTS Nowthatyouunderstandthevariousneedsforthelab,youcanbegintopreparethe lab.Thismayrequiresomeinitialacquisitionsinordertoproperlypopulatethelab.Too manyorganizationspopulatelabsasafterthoughts,bringingintheoldestmachinesin thenetworkandleavinglabtechnicianswithhavingtocannibalizevariousmachinesto trytoputsomethingdecenttogether.Don’tmakethismistake!Thislabistheepicenter oftheproject,somakesureyoupopulateitappropriately.Here’sanexampleofwhat youmightneed.Thescaleoftherequirementswilldependonthescaleofyourproject. Keepinmindthatyoucanrunuptoeightvirtualmachinesperprocessorifallofthe otherrequirements—RAM,harddiskspace—aremet.
HostServerConfigurations Theminimalconfigurationsrequiredtosupportthelabshouldresemblethefollowing list:
▼ HostServer(s)
■ Dualx64quad-coreSMPServer
■ 512MBRAMforthehostOS
■ 256to512MBRAMforeachVMrunningonthehost
■ A tleasttwodisksforRandomArrayofIndependentDisks(RAID)1 (mirroring)
■ PreferablythreeormoredisksforRAID5(stripewithparity)
■ Usethelargestdisksizeyoucan—currentlyabout500gigabytes(GB)
■ Retainabout50GBforthesystemdrive
■ Assignthebulkofthespacetoadatadrive,whichwillstoretheVMs
■ R etainabout50GBforathirddrive,whichwillhosttheshadowcopies producedbyVSS
■ D ualnetworkinterfacecards(NICs)ataminimumspeedof100Mbpsto supportmultipleconnectionstothevirtualmachineshostedbytheserver; verifywiththevirtualizationmanufacturertoseeifyoucanteamtheNICs
■ TechnicianWorkstation(s)
■ 1-GHzprocessor(64-bit,ifpossible)
■ 2GBofRAM,minimum
■ DirectX9supportwithatleast128MBofdedicatedgraphicsmemory
■ DVD-ROMdrive
■ Audiooutput
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▲ ExternalHardDrive(s)
■ Externaldriveof250GBat7200RPMwithUSB2.0orFireWire(IEEE1394)
Thesesystemsshouldsupportlong-termlabrequirements.However,sinceyouareusingthislabasthestartofyourvirtualizationproject,you’llneedclusteredhostswith shared storage, as outlined earlier. These systems will then move out of the lab once you’rereadytomovevirtualizationintoproduction.
VirtualMachineConfigurations Virtualmachinesshouldbeconfiguredasfollows:
1. StandardServerVM RAM
512MBofRAM,minimum
OS
Yourorganizationalstandard
ServicePacks
Allapplicableservicepacksandhotfixesshouldbeinstalled
NumberofDisks
Dependsontherole;canbefromonetothree
DiskSize
DriveC:50-GBexpandabledisk(leavesroomforupgrades) DriveD:70-GBexpandabledisk(optionalbasedonserverrole) DriveE:20-GBexpandabledisk
NetworkCards
AtleastoneNICperVM
CD/DVDDrive
WhenprovidingVMsforuseeitherlocallyorremotely,you shouldincludeISOfilesfortheinstallationmedia;thislets techniciansaddrolestothemachineandgenerallycontrolits featureset
2. EnterpriseServerVM RAM
512MBofRAM,minimum
OS
Yourorganizationalstandardforclusteredservers
ServicePacks
Allapplicableservicepacksandhotfixesshouldbeinstalled
DiskSize
DriveC:50-GBexpandabledisk(leavesroomforupgrades) DriveD:70-GBexpandabledisk(optionalbasedonserverrole) DriveE:20-GBexpandabledisk Installvirtualdisksthatcanbesharedbetweenhosts
NetworkCards
AtleastoneNICperVM
CD/DVDDrive
WhenprovidingVMsforuseeitherlocallyorremotely,you shouldincludeISOfilesfortheinstallationmedia;thislets techniciansaddrolestothemachineandgenerallycontrolits featureset
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3. Bare-MetalVMs RAM
512MBofRAM,minimum
OS
NoOS
ServicePacks
Nofixesorservicepacks
DiskSize
DriveC:50-GBexpandabledisk(leavesroomforWindows Vistainstallation)
NetworkCards
AtleastoneNICperVM
CD/DVDDrive
WhenprovidingVMsforuseeitherlocallyorremotely,you shouldincludeISOfilesfortheinstallationmedia;thislets techniciansaddrolestothemachineandgenerallycontrolits featureset
4. VistaPCVMs RAM
512MBofRAM,minimum
OS
WindowsVistabasedontheeditionsyoudecidedtodeploy
ServicePacks
Allapplicableservicepacksandhotfixesshouldbeinstalled
DiskSize
DriveC:20-GBexpandabledisk
NetworkCards
AtleastoneNICperVM
CD/DVDDrive
WhenprovidingVMsforuseeitherlocallyorremotely,you shouldincludeISOfilesfortheinstallationmedia;thislets techniciansaddrolestothemachineandgenerallycontrolits featureset
5. WindowsXPPCVMs RAM
512MBofRAM,minimum
OS
WindowsXPbasedontheeditionsyouarecurrentlyrunning
ServicePacks
Allapplicableservicepacksandhotfixesshouldbeinstalled
DiskSize
DriveC:20-GBexpandabledisk(leavesroomfortheupgrade)
NetworkCards
AtleastoneNICperVM
CD/DVDDrive
WhenprovidingVMsforuseeitherlocallyorremotely,you shouldincludeISOfilesfortheinstallationmedia;thislets techniciansaddrolestothemachineandgenerallycontrolits featureset
ThesesystemsshouldbeusedassourceVMsforthereproductionofanysystemconfigurationinyournetwork.
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VMUserAccounts User accounts are also critical when setting up VMs for distribution to the technical team.WiththeUnitandFunctionaltestinglevels,itissafetogiveadministrativeaccess tothetechniciansonyourprojectteaminbothserverandworkstationVMsbecausethey arestand-aloneenvironments.Butasyouproceedthroughthetestinglevels,youneed totightendownchangecontrolandgrantaccesstohigh-privilegedaccountsonlytothe labadministrator.Afterall,capturingthechangesrequiredtotheinfrastructureisthe purposeoftheseenvironments. Whenyoudeliverstand-alonemachinesforeithertheUnitorFunctionalenvironment,youshouldendeavortomakeserversdomaincontrollers.Theirbehaviorwill bedifferentfrommemberservers,butitwillbeeasiertoassigndifferentrolestothe accountsthetechnicianswillrequire.Inmanycases,thesetestinglevelswillrequire eitherasinglePCVMoraPCVMcoupledwithaserverVM,wheretheserverisplayingaseriesofdifferentroles. WhenyougrantusersaccesstotheVMsthatmakeupeithertheIntegrationorStagingtestinglevel,yougivethemaccountswithappropriateaccessrights,asoutlinedby theinformationthetechnicalteamwillprovidetoyou.
RequiredServerandWorkstationRoles Withineachtestinglevel,you’llneedtoassignorcreateseveraldifferentmachineroles. Asmentionedpreviously,intheUnitandFunctionaltestinglevels,serverrolescanbe integrated into one single VM, but as you move up the testing ladder, you’ll want to separate different roles to represent the production environment you’re running. For example,yourIntegrationlevelmaystilljoinseveralrolestogetherintoafewmachines, butwhenyougettoStaging,itshouldbeassimilaraspossibletotheproductionenvironment.Stagingisthatlasttechnicaltestbeforeyoustartmakingchangesinproduction itself,soyouneedtogetitright(seeFigure6-3). TIP You can even useVMs to simulate remote sites. Server operating systems include routing capabilitiesthataresimilartothoseofCisco’sdevices.Forexample,inWindows,youcanenable RoutingandRemoteAccess(RRAS)ontwodifferentVMsandusethemtosimulatetheroutingof datafromalocaltoaremotesite.Thenyoucanaddbranchofficeserverrolestothesitelocated behindtheremoteroutingserver. There are also some good router VMs that you can pull down from the virtual appliance marketplace.Iflicensingisanissue,thesefreeappliancesareagoodalternative.Findthematwww .vmware.com/appliances. Intheend,yourlabwillneedtoprovisionseveraldifferenttypesoflevelsandseveraldifferentenvironments.Rememberthatwhenyoubuildthemorepermanenttesting levels or environments, you’ll want to build redundancy into the lab infrastructure.Forexample,theStagingtestinglevelshouldhaveatleasttwodomaincontrollers
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Figure6-3. Thedifferentrolesrequiredinavirtuallab
forredundancy.Andifyousimulateremotesites,you’llalsoneedtoincludereplication enginesinyoursolutiontoreplicateobjectsfromonelocationtothenext. Virtualmachinesoftwarealsohelpsinthisprocess.Oncethemachinesarebuiltand ready,youcanusecertaintoolstoautomaticallyprovisionthesemachinesforuserson eitheracontrolledorself-servicebasis.MicrosoftSystemCenterVirtualMachineManager(SCVMM)isavirtualenvironmentmanagementtoolthatletsyoumanagemultiple hostsandvirtualmachinesthroughafamiliarinterface.Italsooffersaself-serviceportal forthecreationandgenerationofvirtualmachines(seeFigure6-4).Thistool,however, onlysupportsthegenerationofasinglemachineatatime.Ifmorethanonemachine is required—for example, for the creation of an entire e-mail environment, including directoryservers,mailservers,andend-userdevices—youhavetobuilditforthetesters.However,thisisoneofthemajoradvantagesofvirtuallabs:Everymachine,every environmentiscompletelyreusable.
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Figure6-4. SCVMMcanallowend-usertesterstoprovisionandcontroltheirownvirtualmachines.
Becareful,however,ofthepoliciesyouputinplacefortheVMsend-usertesterscan create.Afterall,themajorreasonforthisprojectistoreducethenumberofmachinesin yourdatacenter,notproliferatethem.InordertocontroltheVMsuserscreate,youcan settime-limitpoliciestoautomaticallydestroythemoncetheuser’sworkiscomplete. VMwarealsooffersatoolforlaboratorymanagement.TheVMwareLabManager is a tool that is designed to manage and maintain complete environments, not just singleVMs(seeFigure6-5).Becauseofthis,itiscurrentlymuchmorepowerfulthan theMicrosoftcounterpart. TIP If you are not usingVMware, you might look up other lab management tools. For example, VMLogix(www.vmlogix.com)andSurgient(www.surgient.com)alsoofferthistypeoftool.
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Figure6-5. LabManagercanmanageentiresystemconfigurations.
RequirementsforEachTestingLevel Table6-1providesguidelinesfortherequirementsforeachtestinglevel.Adjustthem accordingtoyourownneeds. Each of the five environments has its own requirements, but fortunately, you can reusemanyoftherequirementsofapreviouslevelforthoseofthenext.Here’sthebreakdownofmachinereuse.
▼ Unitlevel Individualtechniciansworkwiththeirownmachinesstoredonan externaldiskandlinkedtotheirownPC.
■ F unctionallevel AsteammembersgraduatefromUnittoFunctional,they reusetheoriginalindividualmachinestheyhadinUnitsincetheyareno longerneededatthatlevel.
■ I ntegrationlevel Allteammembersbegintosharethesamesetofvirtualand physicalmachinesastheybegintointegratetheirpartofthesolutionintoa singleenvironment.Changecontrolisactivatedtocaptureallpractices.
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TestLevel
Objective
VirtualMachines
PhysicalMachines
Unit
Discoveryofnew featuresandfeature operation
Hostsoftwarewith None;usetheir severalvirtualmachines ownPC
Functional
Automatefeatures andobtainpeer review
SameasUnit
None;usetheir ownPC
Integration Linkallaspectsofthe Severalvirtualized solutiontogether serverswithattached clientsystems
Usetheirown PCtoaccess centralized environment
Staging
Finalizealltechnical proceduresand prepareforfinalacceptancetesting
Serversrepresent small-scaleproduction environmentplusa possibleremotesite
Sameas Integration
Pilot
Finalizealltechnical andadministrative procedures
Production-level machinesboth virtualandphysical environments
Productionhost serversand productionPCs
Table6-1. Requirementsforthefivetestinglevels
■ S taginglevel Alltechnicalteammembersshareanenvironmentthatis ascaled-downversionoftheproductionenvironment.Changecontrolis absolute,andnochangecanbeperformedwithoutbeingtracked.Procedures arecompletelyfinalizedandaretestedfromendtoend.
▲ Pilotlevel Allteammembers,includingadministrativestaff,useproduction systemstotargetadeploymenttoabout10percentofthepopulation.
CREATETHELABENVIRONMENT Theactualcreationofthelaboratoryenvironmentissimpleronceyouunderstandhow itshouldwork.Ifyouwanttogetyourtechnicalteammembersgoingearly,allyouneed todoispreparethevirtualmachinesthatarerequiredforUnitandFunctionaltesting. These are fairly quick to prepare, but you should still proceed with care. Ideally, you willalreadyhaveinitiatedtheacquisitionsrequiredfortheseVMs—externaldrivesand
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perhapshigh-performancePCs—andhavedeterminedwhichvirtualizationtechnology youwanttouseaswellasobtainedthevirtualizationsoftware.Thiswillbethefirstof manysourceinstallationfilesthatthelabwillberesponsibleformaintaining.Youwill alsoneedtoobtainsourceinstallationmediaforalloftheoperatingsystemsyouwillbe workingwith.Tomakethemeasiertoworkwith,transformtheinstallationmediainto ISOfilesbecausetheseactasCDdrivesinvirtualmachines. Onceyou’reready,preparethesetwoenvironmentsinthefollowingorder.Relyon anexistingworkstationwithsufficientcapabilitiestoperformthesesteps.
1. I nstallthevirtualizationtechnologyonaworkstationwithsufficient capabilitiestocreatevirtualmachines.
2. C reateyourfirstvirtualmachine,assigningRAM,diskspace,andnetwork interfacecards.Itisbesttocreateanewfolderwiththemachinenameand storeallVMcomponentfilesinthisfolder.
3. ConnecttheVM’sCD/DVDdrivetotheISOfilefortheOSyouwanttoinstall.
4. P erformtheinstallation,runningthroughyourstandardproceduresforOS installationinyourorganization. TIP Sinceyouwillbeusingaphysical-to-virtualconversiontoolfortheactualtransformationofyour datacenter,youcanalsocreatethismachinebyconvertinganexistingphysicalmachineintoaVM.
5. C ustomizethemachineasyounormallywould,updatethedefaultuser,and applyanyrequiredpatchesorupdates.
6. F oranycopyofWindowspriortoWindowsVista,copythefollowingfiles fromtheDeploy.cabfilelocatedontheappropriateWindowsinstallationCDto anewfoldercalledSysPreponthe%systemroot%drive—usuallytheC:drive:
■ Setupmgr.exe
■ SysPrep.exe
■ Factory.exe
■ Setupcl.exe
F orVistaandWindowsServer2008,usetheSysPreptoollocatedinthe Windows\System32\SysPrepfolder.
ForLinuxoperatingsystems,useacustomscripttopreparethemachine.
7. F orversionspriortoWindowsVista,runSetupmgr.exetogenerateaSysPrep .inffile.Useyourorganizationalstandardstoprovidetheanswersrequiredfor thisfile.CloseSetupmgr.exe.
F orVistaandWS08,runtheComputerImageManagerfromtheWindows InstallationAutomationKit(findtheWAIKatwww.microsoft.com/ downloads/details.aspx?FamilyID=C7D4BC6D-15F3-4284-9123-679830D629F2 &displaylang=en).Onceagain,forLinux,usecustomscripts.
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8. C opytheVM’sentirefolder,renamethefolderandtheVMfilesto“machinename SysPrepped,”andopenthenewmachineinyourvirtualmachinetool.
9. R unSysPrep.exeonthemachinetoselecttheResealoption,depersonalize it,andshutitdown.Younowhaveasourcemachinefromwhichyoucan generateanumberofcopies.
10. RepeatthisprocessuntileachOSinthedatacenterhasbeenreproduced.
11. D ocumenteachmachine,listinguseraccountsandcapabilities;copythemonto theexternaldisks;andprovidethediskstoyourtechnicalteammembers.
That’sit.Nowthatyourteammembersarereadytoproceedwiththeirownwork,you canmoveontocreateandpreparetheworkingenvironmentforthelab,aswellaspreparingtheintegrationandstagingenvironments.
VirtualMachinesandSoftwareLicensing Eventhoughyou’reworkingwithvirtualmachines,youstillhavetobeconscious oflicensingissues,especiallyifyou’rebuildingalaboratorytolast.Forthisreason, we don’t recommend using evaluation copies of software or operating systems. Herearesomegeneralguidelinesonhowyoushouldlicensevirtualmachines.You shouldverifywithyourvendortomakesuretheseguidelinesmeettheirlicensing requirements. ▼ S ysPrepmachine ASysPrepmachinedoesnotrequirealicense becauseitisamachinethatisusedonlytoseedothermachinesand doesn’tactuallygetusedas-is.Onceyou’vecopiedtheSysPrepmachine andstartpersonalizingit,youneedalicenseforthemachine. ■ R unningvirtualmachines Eachmachinethatisnamedandisrunning onaconstantbasisneedstohaveitsownlicense. ■ C opiedvirtualmachines Copiesofvirtualmachinesdonotneedtheir ownlicensesolongastheyarenotrunningatthesametime. ▲ C opiedandrenamedvirtualmachines Eachtimeyoucopyavirtual machineandrenameit,youneedtoassignalicensetoit.Arenamed machineistreatedasacompletelydifferentmachineand,therefore, needsalicense. ForMicrosoftproducts,usingeithertheMicrosoftDeveloperNetwork(MSDN) orTechNetPlussubscriptionswillgiveyouaccesstotenlicensesforeachproduct, thougheachlicenseneedsactivation.Bothsubscriptionssupportthelegalreuseof virtualmachines. IfthehostoperatingsystemisWS03orWS08EnterpriseEdition,youcanrunfour MicrosoftserverVMsatnoadditionalcost.Thismakesagoodargumentformakingthehost systemsrunthisOS.MoreinformationonvirtualmachinelicensingforMicrosoftWindows Servercanbefoundhere:www.microsoft.com/licensing/highlights/virtualization/faq.mspx.
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Whenyou’rereadytobuildthelabitself,aswellasIntegrationandStaging,you’ll needtoperformthefollowingactivities:
▼ Beginwiththebaseserverinstallation(s)forthehostservers.
■ Createfilesharesforthelabrepositories.
■ InstallVMsoftwareonhostservers.
▲ C reateorP2VtheVMsthatsimulateproductionserversandotheraspectsof theproductionenvironment.
You’llfindthatyouneedagreatdealofstoragespace.Youmustplanforstoragespace, keepinginmindthefollowingrequirements:
▼ Spaceforstoringalllabdata
■ S pacefortheinstallationmediaforalloperatingsystemsandforallrequired softwareproducts
■ S pacefortheimagesbuiltduringtesting—imagesofbothVMsand,ifyou’re notusingintegratedhypervisors,forhostsystems
▲ S paceforbackingupvirtualharddisksandduplicatingentirevirtual environments
Onaverage,aminimumof500GBofspaceisrequired,butthisnumberisaffectedby thenumberofdiskimages,VMs,andapplicationsyourprojectcoversanditdoesnot includethestoragespacerequiredonthehostserversthemselves. When you build the Integration and Staging test levels, remember that they need to be as similar to production as possible.Also remember that they don’t need to be identical.Forexample,thereisnoreasontousethesameActiveDirectory(AD)oridentitymanagementforestordomainnamessincetheydonotaffectthePCdeployment process.Ideally,you’llusepropernamesforADcomponents,namesthatmakesense andthatyoucankeeponapermanentbasis.Inouropinion,itisalwaysbesttoactually acquireproperdomainnamesforthispurposebecausetheyarepermanentandthislow costisnotaburdenontheproject’sbudget. Whenyouworkontheclientcomputerportionofthelab,designittotestthesame functions and features currently in use or planned for use in the production environment.Includethesametypesofhardware,applications,andnetworkconfigurations. NOTE With the use of the right hardware, the lab can also be transformed into a portable environment. Several manufacturers are now releasing powerful portable hardware. For example, NextComputing,LLCoffersaportablelabserverthroughitsNextDimensionsystem.Thissystemcan includemultipledual-coreCPUs,loadsofRAM,multipleserialATA(SATA)driveswithlotsofspace, andevenmultiplemonitors,allinatransportableformat.FormoreinformationonNextDimension,go towww.nextcomputing.com/.
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BuildCompleteEnvironments Nowthatyouhaveindividualmachinescreated,youcanusethemtobuildentireenvironments.Thegoalistobuildanenvironmentthatisreusableandeasytorepurpose, andthatfullysupportsthesimulationofanynetworkinfrastructureinyourdatacenter. Thismeansyourlabneedstoprovideseveralbaseservices.
▼ I dentitymanagement,forexample,throughMicrosoftActiveDirectory,witha singledomainforestrunningontwodomaincontrollers
■ E-mailcapability,forexample,throughMicrosoftExchangeServer
■ Databasestorage,forexample,throughMicrosoftSQLServer
■ Clusteringtechnologiestiedtoshareddatastorageusingvirtualharddrives
■ TerminalServicesforclientaccesstothevirtualenvironment
▲ Othertechnologiesasrequiredfortesting/proof-of-conceptpurposes
All virtual machines should be running on top of a free virtualization engine (see Chapter7).Oneofthebestwaystogiveusersandparticipantsaccesstothetesting environmentistocreateamachinetorunTerminalServices.Theadvantageofusing TerminalServicesisthatusershaveaccesstotheenvironmentasmembersofthedomain,givingthemasingle-sign-onexperience.Inaddition,nochangesarerequiredto theirproductionmachines,whichisabonus. Whenthisisdone,youshouldcreateagraphicalmapofwhereeachmachineislocatedandwhatroleitplaysintheinfrastructure(seeFigure6-6).Thistypeofmapwillbe useful,especiallyforthetechnicalstaffthatwillbeusingthelab.Itlaysoutthelocation ofeachmachine,itsname,function,andInternetProtocol(IP)address,aswellasprovidingaglobalviewofhowmachinesinteract. Thepossibilitiesforvirtuallaboratoriesarealmostlimitless.Forexample,alabmade ofVMscanalsocontainandsupportthefollowingtechnologies:
▼ NetworkLoadBalancing(NLB)servicesforthefront-endservers Thislets youtestanddeterminehowfailoverworks,aswellaswhichproceduresare requiredtobuildaduplicateserverfortheadditionofnodestoanNLBcluster.
■ W indowsServerFailoverClustersforback-endservers Thisletsyoutest howserverclusteringworksandhowitneedstobesetup,aswellastest failoverpolicies.
▲ IndependentidentitymanagementorActiveDirectoryforthelab Toensure minimalimpactonexistingnetworkservices,thelaboratoryshouldbesetup withanindependentidentitymanagementinfrastructure.
This is a great place to let your imagination run. If you have access to all of your organization’stechnology,youcantryanyscenarioyoucanthinkof.Whenthetechnical buildsofthetestlevelsarecomplete,theyshouldbefullytestedtoensurethattheydo indeedreproducetheproductionenvironmentandthattheywillsupporttestingofyour
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Figure6-6. Visualmapsoftheenvironmentmakeiteasiertouseandunderstand.
entire virtualization solution, including the creation of new VMs as well as the transformationofexistingphysicalworkloads.Then,oncethisiscomplete,yourlabwillbe readyforprimetimeandwillbeabletosupportallaspectsofthesolutionpreparation.
VirtualLaboratoryDeliverables AnotherareathatprovidesgreatROIwithvirtualmachinesisthedeliverablesyoucan extractfromthem.Sincepreparedmachinesarenomorethanaseriesoffilesinafolder on a disk, they can easily be transported and reused for other purposes than the one intendedduringtheircreation.Theverynatureofvirtualmachinesalsoallowstheuse ofspecialadministrativeandoperationalproceduresthataresimplynotavailableor,if theyareavailable,arealotmorecomplextoperformonphysicalmachines.Hereisan exampleofsomeofthedeliverablesyoucanexpectfromavirtuallab:
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▼ CoreMachines Thesemachinesareusedtogenerateallofthemachinesin thelab.You’llwanttomakesurethesemachinesincludethefollowing:
■ T hemachinesareupdatedwithallsecuritypatchesavailable,aswellasany componentupdatethatisrequired.
■ U pdatethedefaultuserenvironmentinordertofacilitatethecreationof newuserprofiles.Thisdefaultuserprofileshouldincludethecreationof specialadministrativeshortcutsintheQuickLaunchareaoftheWindows toolbar.
■ A ddtwovirtualnetworkinterfacecardstothesemachinesinorderto supportspecialfunctionssuchasclusteringsupport.
■ C reateasingledisk,diskC:,foreachmachine.Additionaldiskscanbe addedwhenthemachinesarepurposed. TIP Youmightliketocreatemultipledisksfromtheget-go.Forexample,forserverVMs,it’sgoodto putallofthetemporaryortransientdataonaseparatevirtualdisk.Thisishelpfulwhenasynchronous replicationisusedbetweensites.Thetemporaryvirtualdiskscanbeeasilyidentifiedandleftbehind. Thiscansaveatonofreplicationtraffic,andfilessuchastheVM’spagefilewillnotbereplicated betweensites.
■ Renametheadministratoraccount.
■ F inally,keepthesemachinesinthisstatetofacilitatetheirupdatewhen Microsoftreleasesnewsecuritypatchesoroperatingsystemupgrades.
■ T woSysPrepMachines Next,youkeepadepersonalizedcopyofthese machines.You’llusethesemachinestopopulateyourvirtuallaboratory.In ordertosupportthis,you’llalsoneedtoperformthefollowing:
■ M akeacopyofbothmachineimages(allfiles)toaspecialVirtualMachine\ Sourcefolderoneachphysicalhost.
■ E achtimeanewmachineisneeded,acopyoftheappropriateeditionof thelocaldepersonalizedmachineismade.Thenewmachineisplacedin afolderidentifyingitspurpose,andthefilesthatmakeituparerenamed. Therenamingprocedureincludesthenameoftheparentfolder,thenameof theconfigurationfile,andthenameofthevirtualharddiskdrive.
■ D ependingonthepurposeofthemachine,asecondorthirddiskcanbe added.Thiscouldbethecase,forexample,withanExchangeorSQLServer machinesinceitwillbeusedtorundatabasesandtransactionlogs.
■ O ncethemachineisready,itisopenedinyourvirtualtool.Becauseitisa depersonalizedmachine,itneedstobepersonalized.Thisincludesanew nameforthemachineandtheinscriptionoftheadministratorpassword.The OSthenproceedswiththepersonalizationofthemachineandrebootsit.
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■ O ncethemachineisrebooted,administratorsneedtoresetitsIPaddresses, determineifasecondnetworkinterfacecardisrequired,joinittoadomain (ifappropriate),andformattheadditionaldisks(ifrequired).
■ O ncethisisdone,themachinecanbepurposed—thatis,itcanhavespecial softwareloadedonittofulfillitspurposeintheenvironment.
■ T heBaseEnvironment Next,youcanconstructabaseenvironmentusing appropriateversionsoftheSysPrepmachines.Astandardnetworkshould includethefollowingmachinebuilds:
■ LDAPServerA Thisservesasthefirstdomaincontroller(DC)inthenew ADforest.
■ LDAPServerB ThisservesasthesecondDCinthenewADforest.You’ll alsoneedtobuildoutthebasicstructureoftheActiveDirectory.
■ E-mailServerA Thissupportse-mailinthenewdomain.
■ T erminalServerA Thisallowsuserinteractioninthedomain.This machinecanincludecomponentssuchasMicrosoftOffice,MicrosoftVisio, WindowsMessenger,andanintegrateddevelopmentenvironment(IDE) tool,suchasVisualStudio.
■ DatabaseServerA ThisisthefirstnodethatispartofaSQLServercluster.
■ DatabaseServerB ThisisthesecondnodethatispartofaSQLServercluster.
Thesemachineshavethefollowingcharacteristics:
■ A llmachinesareverifiedforadditionalpatchesandservicepacksrequired bythesoftwarethatsupportstheirnewpurpose.
■ G roupPolicyobjectsarecreatedinthedomaintofacilitatetheoperationof themachinesaswellasuseraccesstotheenvironment.
■ O ncethemachinesareready,abackupcopyofallmachinesistakento supportthereproductionoftheenvironmentforotherpurposes.
▲ TheCoreTestingEnvironment Usingtheappropriatedepersonalized machine,thecoretestingenvironmentisconstructed.Thisincludesthecreation ofthefollowingmachines:
■ W ebFront-EndServerA ThefirstnodeofanNLBclusterhosting collaborationservices.
■ WebFront-EndServerB ThesecondnodeoftheNLBcluster.
■ SearchServerA Aserverrunningbothindexingandotherjobs.
nceagain,thesemachinescanbecapturedassnapshotsanddeliveredto O otherprojectsfortestingintheirownenvironments.
Thesefourdeliverablescanbereusedatanytimebyanyothermemberofyourorganization(seeFigure6-7).Sinceeachmachinecanincludeseveralgigabytesofinformation,
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they’renoteasytotransport.Insomecases,youcancopythemtoDVDs,butthebest waytodeliverthesemachinesistouseportableUSBdisks.Hookthediskuptoyour server,copyallofthemachinesfordeliverytoit,andvoilà!,aready-madenetworking environment for delivery. You can also store them all centrally and give users access throughTerminalServices. There’salotyoucandowiththesemachines,andthere’salottobedonewiththem. Thefirsttwoareeasytoreusesincebytheirverynature,theywillproducenewandunnamedmachines,butthethirdandfourthrequiremorethought.Forexample,theLightweightDirectoryAccessProtocol(LDAP)environmentneedstoberenamedtoensure theprotectionofyourowntestingenvironmentaswellasrenamingmachines,modifyingtheirIPaddressestoavoidconflicts,andresettingallpasswordstomakesurenoone reusesyourown.
Figure6-7. Anexampleofthefourcoredeliverablesfromthelabandhowtheycanbeused
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REUSEOFTHELABDELIVERABLES Threekeyitemsarerequiredforanyonetobeabletoreuseyourdeliverables.
▼ T heyneedtohaveatleasttwophysicalhostswithsufficientmemoryandhard diskspacetohostthevirtualmachines.Youcanalsoprovidethemwithcentral VMstorageifyourlabhasenoughresources.Butyoumightconsiderachargebackprogramtogettesterstopayfortheenvironmentstheyneed.
■ T heappropriatenumberoflicensesforthevirtualengineyourun.Ifyouuse freevirtualizationtools,youdonotneedtoworryaboutthiselement.
▲ A ccesstothecoreimagesofthevirtualmachinestoreproducethemandcopy themtotheirnewenvironment.Notethatthesemachinesareatleast4GB insize—andsometimesconsiderablymore.Becauseofthis,copyingthese machinescanaffectnetworkbandwidth.Inmostcases,thebestapproachisto useremovabledisks,suchasUSBharddrives,forthecopy,ortostorethem onsharedstoragetousethesharedstorage’sduplicationcapabilities,which avoidsnetworkbandwidthandprovideshigh-speedduplication. Thereuseprocedurevaries,dependingonthedeliverableothertestersdecidetouse.
ReuseofDeliverable1:CoreMachines The first deliverable is the core machines you created. When someone requests these machinesforreuse,youshouldperformthefollowingstepsonthembeforedelivery:
1. Makeacopyofyouroriginalmachines.
2. R enamethemachinefiles;renamethefolder,theconfigurationfile,andthe virtualdiskfile.
3. Openeachofthenewmachinesinyourvirtualizationengine.
4. ModifytheIPaddressandthemachinenameforeachmachine.
5. Eachmachineshouldbeupdated.Allpatchesandupgradesshouldbeapplied.
6. Next,changetheadministrativeaccountpasswordtosecurethenewmachines.
7. Optionally,youcandepersonalizeeachmachinebeforedeliverytotherequestor.
ReuseofDeliverable2:DepersonalizedMachines Thefirstthingyouneedtokeepinmindisthevalidityofthesemachines.Youshoulduse thesemachinesonlyiftheyarerelativelycurrent.That’sbecauseyoudonotwanttohave toapplyseveralsecurityupdatestoallofthemachinesyoucreatefromtheseimages. Theuseofthedepersonalizedmachinesshouldbeperformedwiththefollowingsteps:
1.
hemachinesshouldbecopiedtoallphysicalhostsinthenewlaboratory(if T youaremovingthemtonewlocations).
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2. A ppropriatemachinesshouldbecopiedtonewfolders,andthebasefiles makingupthemachineshouldberenamed.
3. Thenewmachinesshouldbeopenedinthevirtualengineandpersonalized.
4. Thecorefunctionofthemachineshouldbeapplied.
5. Eachmachineshouldbeupdatedasneeded.
Anotherusefulitemyoumightprovidetorequestorsofthedepersonalizedorcoremachinesistheinstallationandconfigurationdocumentationyouusedtocreateyourvirtuallaboratory.Onethingtokeepinmindonthisdocumentationistokeepitshortand tothepoint,providingasummaryoftheinformationrequiredfortheinstallation,then providingcrucialdetails(seeFigure6-8).Thiswillmakeboththefirstandthesecond deliverablemuchmoreusefultoothergroupsinyourorganization.
Figure6-8. Anexampleofthebuilddocumentationtobeused
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ReuseofDeliverable3:TheBaseEnvironment Asyoucansurmise,useofthisenvironmentrequiressomespecialprocedurestoprotectotherexistingenvironments,includingyourownlaboratory,frompotentialdamage. Whenyouchoosetodeliverthebaseenvironmenttoothergroups,savingthemconsiderabletimeinpreparation,you’llneedtoprepareitaccordingtothefollowingsteps:
1. A formalrequesttothevirtuallabmanagermustbesent.Thisrequestmust include:
■ Thenameforthenewenvironment
■ TheDNSnameofthenewdomain
■ Thedown-levelnameforthenewdomain
■ Athree-characterprefixformachinenames
■ AlistofIPaddressestouseforeachmachine
2. A genericadministrativepasswordthatcanbeusedinthepreparationofthe machines.Thispasswordcanbechangedoncethemachinesaredelivered.
3. O ncethisrequesthasbeenreceived,thevirtuallabteamcanproceedtothe preparationofthedelivery.Allmachinesneedtoberenamed.Theadditionof thethree-letteracronymrepresentingthepurposeofthenewlabtotheexisting machinenameshouldbesufficient.
4. T hedomain/forest/securitycontextalsoneedstoberenamedtoavoid duplicationontheinternalnetwork.ForActiveDirectory,toolsand proceduresforperformingthisoperationcanbefoundatwww.microsoft .com/windowsserver2003/downloads/domainrename.mspx.
5. Alladministrativepasswordsneedtobechanged.
6. AllIPaddressesneedtobechanged.
Oncethisisdone,thenewenvironmentcanbedeliveredforuse.Theidealmechanism forthisdeliveryisaremovableUSBharddisksincetheenvironmentismadeupofseveralvirtualmachines,orcentralstorageifyouhaveit.
ReuseofDeliverable4:TheCoreEnvironment LikeDeliverable3,thisdeliverablerequiresspecialproceduresforreuse.Therearetwo waystoreusethissetofmachines.Thefirstconsistsofrenamingthesecuritycontextand allofthemachines,justlikeforthereuseofDeliverable3andusingthesamesteps.The secondistosimplyprovidethisentireenvironmentas-is.Theissuewiththissecondapproachistofindawaytoreusetheentiresetofmachineswithoutimpactinganyother existingenvironment.Thiscanbedoneifyousetupanisolatednetworktorunthisnew instanceofyourlab.Butsinceitiseasytomakemistakesandyoudon’twanttocause anydowntimetoyourownlab,thebestwaytoprovidethisdeliverableforreuseisto usethesameprocedureasforDeliverable3.
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Figure6-9. Anexampleofavirtuallaboratorybuildroadmap
Anotherusefultoolyoucanprovidewithbothofthesedeliverablesisthelaboratory buildroadmap(seeFigure6-9).Thisroadmapgraphicallyportrayswhatwasdoneto createboththesedeliverablesand,therefore,letsotherusersbetterunderstandthecomplexityofyourdeliverable. Oneofthekeyadvantagesyourorganizationwillgainwiththisapproachandthe reuseofyourlaboratorydeliverablesisasignificantreturnoninvestment(ROI)anda vastlyreducedtotalcostofownership(TCO)fortheselaboratories.Imagine,nowwith twophysicalmachinesyoucanruncomplextestingandtrainingenvironmentsthatused torequireonesinglephysicalmachineforeachrole.Before,youhadtoscroungearound tofindleftoverhardwarejustsoyoucouldcreatealaboratory.Now,youdon’tneedto usethisapproachbecauseyoucanjustifythelowcostoftwoproperlysizedmachines, especiallygiventheresultsyoucandeliverwiththem.
VIRTUALINFRASTRUCTURELABORATORY MANAGEMENTPRACTICES AnotherareathatcanprovideloweredTCOisinyourlaboratorymanagementpractices. Becausethisisaproductionlaboratorythatprovidesconstantservicelevels,you’llneed todesignproperprocessesforthemanagementandadministrationofthelab.Sincethe
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labrunsonfreevirtualizationtools,thereareseveralspecialpracticesthatcanandmust beperformedtoensurebothstabilityandsecurityoftheenvironment.Theseprocedures coverseveraldifferentareas:security,specialbuildprocedures,backupanddisasterrecovery,andfinally,maintenance.Eachoftheseneedstobeaddressedinordertomeet thegoalsofthelab.
SecurityPractices One key area of the virtual infrastructure is security. This applies at all levels of the environment.Forexample,becauseitisalaboratory,andbecauseitisbasedonvirtual machines,operatorsmayhavethetendencytoapplylaxsecurityrulesorevenapplyno securityatall—passwordsarefreelyexchanged,thesamepasswordisappliedtoallaccounts,andsoon.Butthisshouldnotbethecase.Sincealaboratoryenvironmentisdesignedtorepresentreality,itshouldbeassecureaspossible,justthewaytheproduction environmentis.Therefore,asastartingpoint,thefollowingsecuritypracticesshouldbe enforcedinthevirtuallaboratory:
▼ Alladministratoraccountsarerenamedfromthedefaults.
■ C riticalpasswords,suchasthoseforthelocaladministratoroneachmachine andthedomainadministratorinthesecuritycontext,areknownbyonlykey people:thelaboratorymanagerandthedesignatedsystemadministrator.Only thelaboratorymanagerisallowedtodivulgethispasswordtoothers,andthis onlyinanextremeemergency.
■ Wheneverapasswordiscompromised,itisresetimmediately.
■ A llserviceaccountsareassignedaspecialcomplexpassword,whichis distributedtoonlythecoreadministrators.Thispasswordiscompletely differentfromthatoftheadministrativeaccounts.
■ U seraccountsuseagenericpassword,whichisdistributedtotheuserthrough internale-mailbutrequiresanimmediateresetoncetheylogintothesystem.
■ A properdelegation-of-authoritystrategyisinuseintheenvironment,granting operatorsonlythoserightsthattheyabsolutelyneedtoperformtheirjob.
■ A properorganizationalunitstructureiscreatedintheLDAPenvironmentto supportthisdelegationmodel.
■ T hedeliveryofsecuritypatchesshouldbemanagedthroughproper infrastructures.Forexample,inWindowsenvironments,youcanuseWindows ServerUpdateServicesinordertokeepthemachinesup-to-dateatalltimes.
■ A corporateantivirustoolshouldbeinstalledandusedtoautomaticallyupdate allofthedefinitionsoneachmachineintheenvironment.
▲ T hephysicalhostsarepartofaworkgroupandarenotpartofthesecurity contextmanagedbythevirtuallaboratory.Specificoperatoraccountsneedto becreatedonthesemachinestoenableoperatorlogonwithouttheuseofthe localadministratoraccount.
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Thislastitemisveryimportantsincethesecurity-contextserversforthevirtuallabare virtual machines. Since the virtual machines cannot start until the host machines are started,joiningthemtothissecuritycontextcauseslogonissuesonthephysicalhosts. Thesehostmachinescanbepartofyourproductiondomaininsteadofaworkgroup,but practicehasfoundthatitisoftensimplerandeasiertosetthephysicalhoststobemembersofaworkgroupthathasthesamenameasthedown-levelnameofthelab’ssecurity context.ThiswaytheyallshowuptogetherintheNetworkNeighborhood. Thepracticesoutlinedherearebynomeansacompletelistoftheactivitiesrequired forsecuringanenvironment;theyneedtobesupplementedwiththenormalprofessional practicesyouusetoenforceasecureenvironment.Theyarebroughttoyourattentionto highlightsomeofthespecificitemsrequiredforvirtuallaboratories.
SpecialBuildProcedures Theverynatureofvirtualmachinesmakesiteasiertosupportcomplexsystembuild procedures.Thismeansthatateachtimeyouperformacriticaloperationduringacomplexbuildprocess,youcantakeabackupcopyofthefilesmakingupthismachineor, evenbetter,takeasnapshotofthemachine.Snapshotsletyoureturntoaspecificpoint intimeonaVM.So,forexample,whenyou’rebuildingacomplexsystem,youcantake severalbackupimagesorsnapshots. Theadvantageofthesetemporarybackupcopiesandsnapshotsisthatwheneveran operationfails,thebackupcopymakesiteasytosimplygobackonestepandstartover again.Thisissomethingthatisimpossibleonaphysicalserver—unlessyouuseadisk imagingtool,whichtakesmuchmoretimethanasimplediskcopyofavirtualmachine. Oncethecomplexinstallationoperationiscomplete,thesetemporarybackupscanbe discarded.Considerthisstrategyduringyourmachinebuilds.
BackupandDisasterRecovery Backupisalsoaplacewhereyoucantakeadvantageofvirtualtechnology.Oneofthe great advantages of working with virtual machines is that they are made up of files located within folders. This enables the ability to include several types of protection levels.
▼ T hefirstlevelofprotectionisprovidedbymanualmachinebackups.Each timeacriticaleventissettooccuronanygivenmachine,itispaused,its stateissaved,andacopyismadeofthefolderthatcontainsitsfiles.Then, themachineisrestarted,theoperationisperformed,andifallgoeswell,the manualbackupmachineisdeleted.Ifnot,operatorscanquicklyreturntothe previousversionofthemachine.
■ T hesecondlevelofprotectionisofferedbyapowerfulfeatureofWindows Server(ifyourhostisrunningWindows):VolumeShadowCopyService (VSS).VSSisadefaultservicethatautomaticallyprotectsdatastoredwithin asharedfolder.Snapshotsarecreatedtwiceadaybydefault,andmultiple snapshotscanbestoredforanydriveorvolumewheretheserviceisactivated
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(64forWS03or512forWS08).Torecoveradamagedmachine,yougotothe Propertiesofitsfolderandrestoreapreviousversion.Toensurethisservice appliestoallvirtualmachines,theirfoldersareallstoredwithinashared folder,andsincedisksaresharedbydefault,eachvolumeisautomatically consideredasharedfolderbyVSS.
■ T hethirdlevelofbackupisthedefaultbackuptechnologies,whichtake backupsoftheinternalcontentsoftheVMs.Theseareusedwheneveracritical eventhasoccurredonasystem.
■ A fourthlevelofbackupcanbeprovidedbyutilitiessuchasRobocopyfrom theWindowsServer2003ResourceKit.Ifyouhavetwohosts,youcreatea scheduledRobocopyjobthattakesallofthevirtualmachinesfromonehost andcopiesthemtotheotherandviceversa.SinceRobocopyisintelligent enoughtocopyonlychangedfiles,thisdoesnottakeuptoomuchoverhead.
▲ A fifthlevelofbackupcanbeprovidedbyyourenterprisebackuptool. Sincevirtualmachinesareonlyfiles,theuseofafilesystemagentshouldbe sufficienttoprotectthesemachinesontape.
Inproductionlabs,backupsareacrucialpartoftheoperationofthelabasawhole.
LabMaintenanceProcedures Specialmaintenancepracticesarealsorequiredforthevirtuallaboratorybecauseofits nature. These include many variations on traditional machine management practices, suchasthefollowing:
▼ WeeklySecurityScan ForWindowssystems,thesystemadministratormust performaMicrosoftBaselineSecurityAnalyzerscanontheentiredomainonce aweektoensureallmachinesaresecure.Thiscanbemitigatedbytheuseof WindowsServerUpdateServices,sincethisupdateserviceprotectsmorethan justtheoperatingsystem.Useappropriatetoolsfornon-Windowsenvironments.
■ W eeklyAntivirusVerification Onceaweek,thesystemadministrator shouldensurethatpropervirusdefinitionsareappliedtoallmachinesandthat nomachineremainsunprotected.Also,thescheduleinwhichantivirus(AV) scansrunshouldbestaggered.Thispreventsperformanceissuesonaphysical hostwhenallVMstrytorunAVscansatthesametime.
■ W eeklyMaintenanceWindow Onceaweek,ifrequired,aspecial maintenancewindowisreservedtoperformmajormaintenanceactivitieson theenvironment.
■ W eeklyFreeSpaceVerification Onceaweek,thesystemadministrator verifiesthatthereareappropriateamountsoffreespaceonthedisksofboth thephysicalhostsandthevirtualmachines.
■ W eeklyEventLogVerification Onceaweek,thesystemadministrator verifiesthattherearenountowardeventsintheeventlogsofthevarious machinesinthelaboratory.
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■ W eeklyBackupVerification Onceaweek,thebackupadministratorensures thatbackupsareproperlyperformedonallmachinesandreportstothesystem administrator.Inaddition,thesystemadministratorverifiesthatshadow copiesareworkingproperlyonbothphysicalandvirtualmachines.
■ C hangeLog Eachtimeamodificationisperformedontheenvironment,an entryiswrittentothelaboratorychangelog.Thishelpsensurethateventsare properlyrecorded.
▲ SpecialMachineDeletionProcedure Manualmachinebackupsare performedeverytimeasignificanteventoccursonamachine.Iftheevent ormodificationissuccessful,thisspecialbackupshouldbedeleted,but sometimesthisbackupisnotremoved.Therefore,regulardeletionevents musttakeplace.Becauseoftheconfusingnatureofworkinginthefilesystem withoutanyreallinktothevirtualengine,itmaybepossibletodeletethe wrongmachine.Toensurethisdoesnotoccur,machinesthatneedtobe deletedshouldbemovedtoaspecialTobedeletedfolderpriortodeletion. Thenanoverallsystemcheckshouldbeperformed.Ifallmachinesare operatingproperlyinyourvirtualengine,deletioncanproceed.Ifthewrong machineiscopiedtothisfolder,oneormoremachineswillnolongerbe availableinthevirtualengine.Thesameappliestosnapshots.Mostvirtual enginescanstoreupto512snapshotsofavirtualmachine.Youmustmanage thesesnapshotsinordertoretainonlyvalidcopies.
These procedures are added to normal maintenance procedures that apply to all IT environments.
VIRTUALLABBESTPRACTICESSUMMARY Oneofthemostimportantfindingsyoushouldcomeawaywithfromworkingwithvirtualtechnologiesisthatitispossibletobuildandtestalmostanyfunctionalityinanetwork environmentwithinamatterofafewweeks,sometimesevenafewdays.Nowthatyouhave corevirtualmachinestoworkwithaswellasacomprehensiveinstallationinstruction set,thetimerequiredtoprepareaworkingenvironmentshouldbegreatlyreduced.In addition,herearesomerecommendedbestpractices.
▼ T oincreasethespeedoftheimplementationofatestingenvironment,reusethe deliverablesfromthevirtuallaboratory.
■ T heprocessofacquiringhardwareinsupportofatestingenvironmentshould bestreamlined.Perhapsyoucouldconsiderhavingabankofmachines onhandatalltimes.Thisbankofmachinescanthenbeusedasapoolfor allocationtodifferenttestingenvironments.Tofacilitatethecreationofthis pool,youmayconsidermovingallofyourcurrenttestingenvironmentstoa virtualinfrastructure.Thisshouldfreeupseveralmachines.Youcanalsoadd moremachinestothispoolasyouvirtualizeyourproductionservers.
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■ P 2Vtools,whicharediscussedinChapter9,mustbepartoftheoveralllab toolkit.Theyalsowillberequiredfortheactualmigrationyouwillperform.
■ M achinesusedinsupportoftestingshouldbemultiprocessorsystemsthat includelotsofRAMandlargeamountsofdiskspacesothattheycansupport multiplevirtualmachines.
■ T rainingorfamiliaritywithvirtualmachinesisessentialtothesuccessofany virtuallab.Technicalstaffwithlittleornoexperiencewithvirtualmachine technologywillfinditconfusingatfirst.
■ A glossaryoftermsandterminologyisagoodideatoensurethateveryoneis onthesamepage.
■ K eepthehostmachinesoutofthesecuritycontextyoucreateinyourtesting environment.Otherwise,thismaybecomeaproblemsincethemachines managingthesecuritycontextarevirtualmachinesanddon’trununtilthe physicalhostisup;yet,tologintothephysicalhost,youneedaccesstothese machines.
■ I tisagoodideatohaveacommunicationplaninplace.Forexample,an introductorydocumentcouldbecraftedfromthesetwoarticles.Sucha documentisusefultobringnewtechnicalstaffquicklyuptospeedonvirtual technologies.
■ I tisagreatideatohaveagraphicalrepresentationofthevirtuallabtoprovide totechnicalstaff.Thisgraphicalmapisoftenthesinglemostimportantpieceof documentationoperatorsuse.
■ A lso,keepachangelogforallactivitywithinyourtestingenvironment.This logcanbeinvaluablewhentryingtotroubleshootyoursystems.
▲ F inally,youmightconsidergivingyourstaffsomehands-onexperience withvirtualmachines.ForWindowsenvironments,youcanaccessVMsthat MicrosoftiscurrentlyhostingthrougheitherMSDNorTechNet.Bothprovide theabilitytorunthroughspecificexercisesetsdirectlyonavirtualmachine, lettingyougainvaluableexperienceatnoothercostthanthetimeittakes. Thismightbethebestwayforyourtechnicalstafftogetuptospeedonthis technology,andit’scompletelyfree.FindoutmoreaboutTechNetVMsat http://technet.microsoft.com/en-us/bb738372.aspx.
Nowthatyou’reupandrunninginyourvirtuallab,youcanstarttoreapitsbenefits. This section outlines quite a few, but the one you’ll certainly appreciate the most, or rather,theonethatwillmakeyoursuperiorsappreciateyouthemostisthecostsavings you’llgainfrommovingalltestingenvironmentsfromphysicaltovirtualenvironments. That,coupledwiththeflexibilityofvirtualmachinescomparedtophysicalones,will greatlyenhancethewayyouworkwithandlearnnewtechnologiesfromnowon.
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MOVEONTOTHEVIRTUALDATACENTER Building a virtual lab is the best way to get used to virtualization technologies. You becomefamiliarwithVMcontents,VMbuilds,VMmanagementpractices,andmore. Practicewell.Thenextstepistomoveforwardwiththebuildofyourhostsystemsto createthestartofyourresourcepool.Inthiscase,you’llmostcertainlyusehypervisors andsharedstorage.Then,you’llbereadytotesttheP2Vmigrationsthatwilltransform yourdatacenterintoavirtualinfrastructure. Thenextchapterswilltakeyouthroughtheseprocesses.Chapters7and8outline how server virtualization works and help you choose your virtualization solution. Chapter9letsyoulearnhowtoworkwithP2V.Chapter10outlineshowdesktopvirtualizationworksandhowyoucanchooseyourownsolution.Chapters11and12outline howapplicationvirtualizationworksandhowitintegrateswiththeformertwotocreateacompletelydynamicdatacenter.
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S
ervervirtualizationtechnologiesarethedrivingforcebehindthemovetodynamic datacenters. While the concept of building a datacenter that could respond dynamically to business requirements has been around for decades, it was not until VMware introduced production-level server virtualization technologies that the truedynamicdatacenterbecamepossible. Foryears,theanalystfirmGartnerhasbeentoutingthefourstagesofITmaturity asbeing:
▼ Basic OrganizationsuseadhocITprocedures.Mostadministratorsdothings ontheirownandtherearefew,ifany,standardprocedures.
■ S tandardized Organizationsbegintheuseofstandardoperatingprocedures (SOP),andalladministratorsrelyonthemtorunthedatacenter.Issuesare easiertodealwithbecauseeveryoneknowsthestartingpointofaproblem.
■ R ationalized Organizationsbegintoremoveextraneousequipmentand servicesfromthenetwork.Whileorganizationsinpreviousstagessimplyhave atendencytoaddtotheinfrastructurewhentheneedarises,therationalized organizationputsrulesandguidelinesinplacetoavoidaddingtothe infrastructureunlessitisabsolutelynecessary.Forexample,insteadofadding morestoragespacetocentralfileshares,theorganizationwillreviewthefilesit hasinstorage,determinetheirvalidity,archiveoutdatedandunusedfiles,and thereforemakeadditionalspaceavailablefromexistingresources.
▲ Dynamic Organizationscanresponddynamicallytobusinessneeds.Volatile workloadscanbegeneratedasneededandremovedfromthedatacenter oncetheirrequirementhasbeenfulfilled.Workloadsautomaticallyrunwhen requiredbasedonestablishedpolicies.Alloperationsarestreamlined,and issuesarerarer,butoftenmorecomplexand,therefore,moreinterestingforIT personneltodealwith.
Eachofthefourstagesservesasthefoundationforthenext.Operationsarebasedon threekeyelements—People,PCs,andProcesses—orthethreePsofIT(seeFigure7-1).
▼ P eoplemakeupthecoreofanydatacenter.Theyarethedrivingforceofthe standardsthatareimplementedtostreamlineoperations.
■ P Csrepresentthetechnologyaspectofthedatacenter.Bychoosingtheright technologies,organizationsreduceoverheadandsimplifyITmanagement.
▲ P rocessesformthecoreoftheoperationspractice.Standardprocessesare basedonSOPstomakesureallpersonnelrespondinthesamemanner wheneverataskneedstobeperformed.
Whenyoumovetoservervirtualization,youimmediatelygaintheadvantagesofadynamicIT,butifyoudonothavetheotherelementsofthefoundationinplace,youwill simplyaddtothecomplexityofyouroperationsandmaywellfindyourselfinasituationwhereyouproliferatetechnologiesevenmorethaneverbefore.
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Figure7-1. ThefourstagesofITmaturityandtheirfoundation
NOTE Formoreinformationonhowtobuildadynamicdatacenterbasedonstandardoperating procedures,seeWindowsServer2008:TheCompleteReferencebyRuestandRuest(McGraw-Hill, 2008). As you decide how to implement the dynamic datacenter, you will find that you needtoaddressfourkeyaspectsofservervirtualizationbeforeyoucanrunthetechnologyinyourdatacenter.Theseinclude:
▼ Howtochooseaservervirtualizationtechnology
■ Howtoworkwithvirtualworkloads
■ Howtoprovisionnewvirtualmachines
▲ Howtoprovisionvirtualmachinesfromexistingphysicalworkloads
As you address each of these aspects, you become more and more familiar with how youwillneedtomanageyourdatacenteronceyourservervirtualizationtechnologyis inplace.
CHOOSEASERVERVIRTUALIZATIONTECHNOLOGY Theservervirtualizationtechnologyyouchoosemustmeetallofyourrequirements. Foryoutomaketherightchoice,youmustbeawareofandunderstandwhatthemajor choicesareandwhichtechnologiesofferthemostfeaturesbasedonyourownrequirements.Chapter2introducedtheconceptofservervirtualizationandoutlinedthemajor playersinthisfield.Whilethereareseveraldifferentmanufacturersofferingvirtualizationengines,therearereallyonlythreethatofferextensivefeaturesets:VMware,which was the founder of server virtualization on x86 technologies; Citrix, which, with its
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purchaseofXenSourcein2007,nowofferstheXenServerlineofproducts;andMicrosoft,whonowoffersvirtualizationthroughtheHyper-VcodeinWindowsServer2008. MostothervendorsoffertechnologiesthatarebasedontheXenopen-sourcecode.This means that vendors such as Oracle, Sun, Virtual Iron, and more, really offer nothing muchdifferentthanCitrix,sincealloftheiroffersarebasedonthesamecode. Butinorderforyoutochoosetherightproductforyourneeds,youmustfirstbe awareofwhatmakesupwhateachvendoroffers.Then,youwilllooktopricingand implementationcosts.Onceyoubegintounderstandwhichproductbestfitsyourbill, youmustlooktowhatyouneedtodoandhowbestitcanbeimplemented.Thisdecision processisbasedonthevirtualizationimplementationflowchartpresentedinChapter3, but this time, with a focus on server virtualization. Once again, looking to the offeringsofeachvendorwillassistyouintheprocess.Finally,yourdecisionwillbecrystallizedthroughtheanalysisofthemetricsforeachmajorhypervisor—howmanyvirtual machines can run on one host, how hosts are managed, which operating systems are supportedinthevirtuallayer,andsoon—whichwillhelppositioneachvendorinthe marketplaceandviewitslong-termvalue.
TECHNOLOGIESANDSCENARIOS Thethreemajorvirtualizationvendorsofferseveraldifferentsolutionsforvirtualization. Table7-1providesareviewofthedifferentofferingseachvendorhasandcategorizes themaseithersoftwarevirtualization(SoftV)orhardwarevirtualization(HardV). Two of these major vendors—VMware and Microsoft—also offer other desktopbasedproductsthatemulateSoftVandcanrunonavarietyofoperatingsystems.Forexample,VMwarefirstmadeitsnamethroughVMwareWorkstation,itsflagshipproduct andtheonetheyusetointroducemostnewfeaturesetsfortheirvirtualizationengine. Eachoftheseengines,SoftVandHardV,makesuppartofthevirtualizationsolutionyou implement.Forexample,inChapter6,youreliedmostlyonfreevirtualizationtechnologiestotransformyourlaboratoryintoavirtualdevelopmentandtestingground.Thisis theprocessmostorganizationsusetobeginworkingwithvirtualizationengines.Infact, mostorganizationsuseastandardprocessfortheimplementationofservervirtualizationtechnologies(seeFigure7-2). Theybeginwithtestinganddevelopmentenvironments.Then,whentheyhavebecomemorefamiliarwiththesetechnologies,theymoveontothevirtualizationoftheir productionworkloads.Almostallworkloadscanbevirtualized,anddoingthisgreatly reducesthephysicalfootprintofyourdatacentersolongasyougetthepreparationofthe hostsright(asperChapter5).Onceyourserverworkloadsarevirtualized,youcanthen looktobusinesscontinuitysolutions.Sinceallyourworkloadsarenothingbutfilesina folder,thesestrategiesaremuchsimplertoimplement.Finally,onceyourinfrastructure issecuredandprotected,youcanbegintoworkwithmoreadvancedvirtualizationstrategies, transforming your workloads into dynamic services that run based on policies. Thesepoliciesdictatewheretheworkloadmustbeplaced,howmanyresourcesmustbe allocatedtoit,andwhenitshouldrun.Atthisstage,youentertherealmofthedynamic datacenterandbegintotrulyprovideITasaservicetoyourend-usercustomers.
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Manufacturer Product
SoftwareVirtualization
HardwareVirtualization
VMware
VMware Server
Freesoftware-based virtualizationtool; version2includesitsown webserver(Apache)for management;runsx86or x64virtualmachines(VMs)
VMware
ESXServer
32-bithypervisor,but 64-bitmemorymanager; mostusedandmost provenonthemarket; runsx86orx64VMs
VMware
ESXi
Freeintegrated hypervisor;available withhardwareorasa separatedownload;runs x86orx64VMs
Citrix
XenServer allversions
64-bithypervisor;based onopensource;relieson MicrosoftVirtualHard Drive(VHD)format;also includesafreeversion (XenServerExpress); runsx86orx64VMs
Microsoft
Virtual Server
Microsoft
Hyper-V
Freesoftware-based virtualizationtool;relies onWebinterface;ifused withSystemCenter VirtualMachineManager (SCVMM),Internet InformationServices(IIS) isnotrequired;runsonly x86VMs
Table7-1. SoftVandHardVOfferingsfromtheThreeMajorVendors
64-bithypervisor; integratedwithWindows Server2008;runson eitherServerCoreor theFullInstallation; interoperateswithCitrix; runsx86orx64VMs
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Figure7-2. Thefourstagesofservervirtualizationimplementation
There are, however, several stages of implementation before you get to the point where your workloads are dynamically generated and managed, but each step is rewardinginitself,asyouwilldiscover.
ServerVirtualizationScenarios Asyoucansee,severalscenarioscanbesupportedthroughtheimplementationofserver virtualizationmachines.Theyrangeincostandcapabilities,buteachoffersfeaturesthat simplycannotbesupportedwhenusingphysicalmachines.
▼ SystemTesting EveryITorganizationhasputinplacesomeformoftesting laboratoryforthepurposeofexaminingandunderstandingnewtechnologies andhowtheycouldfitintotheirnetwork.Usually,thesetestingenvironments arescroungedtogetherfrombitsandpiecesthatareleftoverfromthe productionnetwork.Theresultisalow-cost,butnotveryfunctionaltesting environment.AsseeninChapter6,virtualizationcanhelpbyallowingIT tobuildcomprehensivelaboratoryenvironmentsusingonlyafewphysical devicestohostaplethoraofvirtualmachines.Usingundoabledisksandvirtual machineduplication,ITcanreproduceanyscenarioandcreatecomplexvirtual testingenvironments.Itisevenpossibletousephysical-to-virtualcapture enginestomakeavirtualduplicateofphysicalmachinesrunninginproduction.
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■ S oftwareDevelopment Everysoftwaredeveloperhasbeenfacedwiththe needforhighprivilegesontheirsystem.Thisiscompletelyunderstandable becausedevelopersneedtoinstallandtestsoftwareastheydevelopit.In locked-downenvironments,thiscanbecomeasignificantissue,butnotif youareusingvirtualmachinesinsupportofthedevelopmenteffort.Witha virtualmachinerunningonadeveloper’sworkstation,thedevelopercanbe freetohavecompleteaccessrightsinthevirtualmachinewhilethephysical workstationcanremaincompletelylockeddown.Bestofall,allyouneedtodo issupporttheoriginalvirtualmachine.Ifthedevelopersbreakit,youjustgive themanothercopyoftheoriginalmachine.
■ T raining Everytechnicianthatisresponsibleforthesupportofcomputer trainingcenterswillmostdefinitelyprofitfromvirtualization.That’sbecause normally,eachtimeacourseisrun,youhavetodeviseameanstoreturneach PCtothecoursestartingpoint.Inaddition,youneedthemeanstorepurpose thePCinsupportofothercourses.Virtualmachinesareidealforthisfor severalreasons.First,theyareeasytorepurpose—allyouneedtodoiscreate acopyofanoriginalmachineforthecourseandthensimplythrowitaway oncethecourseiscomplete.Second,virtualmachinescancontainanyx86 operatingsystem.Thismeansthatevenaclassroomthatwasoriginallycreated tosupportproductivitytrainingontoolssuchasofficeautomationsoftware canbecomeacompleteandcomprehensivetechnicaltrainingcenterthatcan eventeachadvancedoperatingsysteminstallationcourses.Allyouneedis theproperamountofRAMonthePCs,largerdiskdrivestocontainvirtual machineimages,andafastnetworktocopymachinesfromacentrallocation. Oncethisisdone,yourtrainingroomscansupportoperatingsystem,complex ITinfrastructure,andevendevelopmenttraining.Ofnote:Severalfirms offeringtechnicaltrainingcoursesnowrelyexclusivelyonvirtualmachines.
■ H elpDesk Inenvironmentsthatofferhelpdeskandsupportservices, virtualizationcanbringhugebenefits,especiallyifthetechnicianneedsto supportmultipleoperatingsystems.Formerly,techniciansneededtohave accesstomultiplePCswithkeyboard,screen,andmouseswitchestochange fromonetoanother.Today,eachsupporttechnicianonlyneedsonesinglePC withmultiplevirtualmachinesonittosupportanynumberofclients.Thisis especiallyusefulinoutsourcedsupportcentersthathavemultipleclients,each withtheirownparticulardesktopenvironment.
■ E nvironmentStandardization Oneadditionaluseofvirtualizationisin thecontrolanddeploymentofcustomapplications.Usingvirtualmachines, ITgroupscanprepareaworkingversionofanapplicationandinsteadof deployingtheapplicationonaphysicalmachine,deployacompletevirtual machinetoendusers.Thisensuresstandardscomplianceandcanhelpkeep supportcostsdown.MoreonthiswillbecoveredinChapter10aswediscuss virtualdesktopinfrastructures.
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▲ PhysicalServerConsolidation Overthepastdecade,organizationshave seenaproliferationofservermachinesforseveraldifferentreasons.In manycases,thesemachinesrunwithminimalutilizationoftheirresources. Virtualizationofferstheopportunitytoconsolidateserverhardware,reducing thenumberofphysicalhostsrunninginadatacenter,butmaintaining independentvirtualmachinesforeachfunctioncurrentlydeployedinthe organization.Inaddition,theavailabilityofphysical-to-virtualmachine migrationtoolsmakesthisscenarioattractiveandsimpletodeployinanydata center.Thisisthemostcost-effectivereasonfordeployingservervirtualization.
Themostimportantpointtorememberaboutvirtualizationisthateachvirtualmachine canbetreatedasaphysicalmachinewithinthenetwork—amachinethatcancommunicatewithothers,eithervirtualorphysical.ITcanmanagevirtualmachinesthesameway itmanagesallothermachines.Infact,ITcanevensendacommandtothephysicalhost machinetowakeupavirtualmachinebeforeinitiatinganoperation,suchasasoftware deployment.Andasyou’llsee,manyvirtualizationvendorshavetakenextrastepsto include comprehensive virtualization management tools to cover any situation you’ll runintowhenworkingwithbothphysicalandvirtualengines.
OtherVendorOfferings Chapter 1 outlined that it may well be that you end up having to run more than one hypervisorinyourdatacenter.Theimpactisnotsooverwhelmingwhenyourunhypervisorsfromthethreemajorvendors,sinceeachhasinvestedheavilyinmakingsure theirmanagementtoolssupporttheothers’products.Butissueswillariseifyouhaveto runhypervisorsthatarenotsupportedbythemanagementinterfacesyouhaveselected, becausethenyou’llhavetomaintainandrunmorethanonemanagementinterface.This willhaveanegativeimpactonthedynamicdatacentersinceyouwillnotbeabletocentrallymanagevirtualworkloadsthroughpolicies. Oracle,forexample,hasofficiallystatedthattheywillnotsupporttheirproducts onanyotherhypervisorthanOracleVM(seeOracleVMFrequentlyAskedQuestions at www.oracle.com/technologies/virtualization/docs/ovm-faq.pdf under “Support Details”).Infact,theyarenowofferingprepackagedversionsoftheirapplicationsin “templates,”whicharereadytorun(onlyonOracleVM)anddonotrequireinstallation.Thisisodd,sincetheyoffertheirproductsonavarietyofserverplatforms—IBM, HPUX, Microsoft Windows, varieties of Linux, and more—however, because of this policy,organizationschoosingtouseOracleapplicationswillhavetoseriouslyconsider iftheneedfortheseapplicationsjustifiestheintroductionofanother,non-mainstream hypervisoranditsaccompanyingmanagementtoolsintheirdatacenter.OracleVMis yetanotherversionofthefreeXen-basedopen-sourcehypervisor,butbecauseofthe changesOraclehasmadetothiscode,youmustrelyonthecustombrowser-basedmanagement utility Oracle offers with Oracle VM to control its operation. For enterprise Oraclecustomers,OracleoffersEnterpriseManager,whichhasbeenupdatedtoinclude OracleVMmanagement.
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NovellandRedHatalsoofferaXen-basedvirtualizationengineintheirLinuxdistributions. Once again, these are not versions that are managed by mainstream virtualization management engines and, because of this, will require the addition of other managementtools. Parallels(www.parallels.com)offersVirtuozzo,whichisapartitioningplatformthat supportsthedivisionofhardwareresourcesintoseparatecontainers,lettingseveraldifferentvirtualmachinesrunonthesamehardware.Originally,thisproductwasdesigned torunmultipleinstancesoftheircustomoperatingsystem.Parallels(formerlySWSoft) hasbeenworkingatdevelopingamoregeneral-purposevirtualizationenginetocompetewiththeVMwaresoftheworld.Withthisnewvirtualizationengine,Parallelshas partnered with other organizations—for example, Quest Software—to support virtual desktopinfrastructures.Theirrealvirtualizationengineisnewtothemarketthoughand seemsuntriedasofyet. Ofalltheothervendorsonthemarket,VirtualIron(www.virtualiron.com)offersthe mostadvancedselectionoffeaturesforitsvirtualizationplatform.Formanyyears,VirtualIronhasbeenmarketingitsproductsaslow-costdatacentervirtualizationsolutions, butwiththecompetitionheatingupbetweenthethreemajorvendors,VirtualIron’sofferingshavelostthisedgeinmanyrespects. Onethingissure:Largedatacenterswillendupmanagingmorethanonehypervisor foravarietyofreasons.Becauseofthis,itwillbeimportantfortheseorganizationsto makeacarefulselectionwhentheychoosewhichvirtualizationmanagementsystemto use.MoreonthistopiciscoveredinChapter16.
VMwareTechnologyComponents VMwareoffersitsvirtualizationtechnologiesthroughtheVMwareVirtualInfrastructure (VI), which builds on its free hypervisor product (ESXi) or its paid hypervisor product (ESXServer)tocreateacompletecomplementofmanagementtoolsforthedynamicdatacenter.Infact,VMwareisthevendorthatcurrentlyoffersthemostcompleteselectionof virtualizationmanagementtools,coveringthemostimportantmanagementactivitiesany datacenterrunningvirtualworkloadsrequires.Thesefunctionsincludethefollowing:
▼ Centralmanagementconsole
■ Updatemanagementforboththehypervisorandthevirtualworkloads
■ Backuptechnologiesforboththehostandthevirtualworkloads
■ Disk-sharingtechnologyforhostserversinsupportofhighavailability
■ High-availabilitycomponentstomanagehostandsitefailovers
■ L ivemigrationcomponentstomoveaworkingvirtualmachinefromonehost toanother
■ L ivestoragemigrationcomponentstomoveaworkingvirtualmachinefrom onestoragecontainertoanother
■ H ostresourcemanagementcomponentstomoveresource-intensivevirtual machinestohostswithavailablecapabilities
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■ Powermanagementcomponentstopoweronoroffhostserversasneeded
■ L abmanagementcomponentstosupportthegenerationandmanagementof entireworkingenvironmentsaswellasindividualvirtualmachines
■ S tagemanagementcomponentstomoveITsolutionsthroughvarioustesting anddevelopmentstages
▲ ScriptingcomponentstomanageandautomateVMandhostmanagement
Thisselectionoftoolsiscurrentlythemostcomprehensiveonthemarket.VMwarehas beeninthevirtualizationmarketforoveradecadeandbecauseofthis,theirofferingis stillthemostmaturethatisavailable. Inaddition,VMwareofferingsscalewithuserrequirements(seeFigure7-3).Organizationscanbeginwithfreevirtualizationtechnologies,relyingonESXiasafreeintegratedhypervisor.TheESXidownloaddiscussedinChapter5givesorganizationsaccess totheVMwareInfrastructureClient(seeFigure7-4),whichallowsthemtomanagehost serversonanindividualbasis.However,ESXiisatruehypervisorthatisdesignedto maintainasmallfootprintandyetactasanorchestratortoexposehardwareresourcesto virtualmachines(seeFigure7-5).OrganizationsworkingwithESXiwillautomatically gainaccesstotheVirtualMachineFileSystem(VMFS)discussedinChapter2tocreate sharedstoragecontainers,aswellastheVirtualSymmetricMultiprocessing(SMP)enginetoallowVMstoaccessmorethanoneprocessorcore.Together,thesetoolsmakeup agoodstartingpointforanyorganization,especiallyconsideringthattheyarefree. NotethatsupportincidentsarechargedseparatelywhenusingtheESXicomponents. Organizations can purchase them on an incident-by-incident basis, purchase incident packsinthreeorfivebundles,oracquireGoldorPlatinumSupportforeachhostserver.
Figure7-3. ThebaseofferingsfromVMware
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Figure7-4. ManaginghostsandVMsthroughtheVMwareInfrastructureClient
ThedifferencebetweenVMwareESXiandESXisthattheESXiimageonlyincludes thehypervisor,whiletheESXimagecontainsboththehypervisorandthemanagement partitionfortheserver.WhenyourunESXi,youmustusearemotemachine—physical orvirtual—tomanagethehost.WhenyouuseESX,youcanrelyonthemanagement partitiontomanageandmaintainthehostlocally. OneofthemostpowerfulfeaturesofbothVMwareESXandESXiisthesupportfor keymemorymanagementfeatures.Theseinclude:
▼ Min/MaxMemorySettingsonVMs Thisfeatureletsyouassignaminimum andamaximummemorysettingtoaVM.WhentheVMisrunning,ESX willbeginbyassigningtheminimumamountofRAMtotheVM.IftheVM requiresit,ESXwillincreasetheamountofRAMfortheVMuntilitreachesthe maximumsetting.
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Figure7-5. TheVMwareESXandESXiarchitecture
■ R AMOvercommitment ThisfeatureletsyouallocatemorememorytoVMs thanexistsonahost.WhenyoubuildaVMortransferaVMtoanESXhost, youcanassignminimumandmaximummemoryvaluestotheVMthroughthe Min/MaxMemorySettings.Themaximummemoryvalueletsyouevenassign morememorythanisavailableonthehost.Then,ESXwillrelyonpolicy-based VMmanagementtomovetheVMtoanotherhostwithappropriateresources shouldtheVMrequireallofthememoryyouallocatedtoit.
■ T ransparentPageSharing Thisfeaturestoresonlyonecopyofaduplicate fileinhostRAM.ThisfeatureispowerfulandisthereasonwhyVMwarehosts canrunmassivenumbersofVMsonhostswithsignificantlylessmemorythan otherhypervisors.Forexample,ifyoursystemishostingtenWindowsServer 2008VMs,eachVMwillstoreonlyonecopyofthefilesthatmakeupitscore processesduringoperationinRAM.Thiscansaveasmuchas40percentofthe RAMrequiredtorunVMsinsomescenarios.
▲ MemoryBallooning ThisfeatureletsyourecovermemoryfromVMsthatare notusingitandallocateittoothers.ThisletsESXmanagemoreworkloadsby dynamicallymodifyingmemoryallocationstotheVMsitmanages.
ThesefeaturesmakeESXandESXithepowerfulhypervisorsthattheyaretoday.
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Figure7-6. TheVMwareVirtualCentermanagementinterface
OnceorganizationsaremorefamiliarwithESXi,theycanmoveuptotheVirtualInfrastructureFoundation,whichincludesthreeadditionaltools.ThefirstisVirtualCenter (nowvCenter),thehubofallVMwareVImanagement(seeFigure7-6).VirtualCenteris designedinsuchamannerthatitgrowswithanorganization’sneeds,addingfeatures andfunctionalityasnewtoolsareaddedtotheinfrastructure.Becauseofthis,administratorsneverneedtolearnanothertool,onlybecomefamiliarwiththeadditionalfunctionsitcanhost. Inaddition,FoundationincludesbothUpdateManagerandConsolidatedBackup, options that also are made available as additional features within VirtualCenter (see Figure7-7).UpdateManagercanmanageupdatesforbothhostcomponentsandvirtual machines(seeFigure7-8).Forexample,whenchangingorupdatingESXi,itreplacesthe entirefirmwareimage,butalsoprovidesarollbackpathshouldsomethinggowrong withtheupdate.Whenworkingwithvirtualworkloads,itreliesontheinternalupdate enginewithintheclient,suchasWindowsUpdatewithinWindowsVMs.
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Figure7-7. VMwareVirtualCentersupportsadditionalfeatureplug-ins.
ForbackupofVMs,youcanrelyonVMwareConsolidatedBackup(seeFigure7-9). Consolidatedbackupworkswithsharedstoragetechnologiestosupportthecreationof snapshots,thenthegenerationofbackupsfromthesnapshots,havinglittleornoimpact ontheoperationoftheVMsandthehoststhatmanagethem. VIStandardEditionmovesupthescaletoofferadditionalservices.ThemostsignificantadditionavailablethroughtheStandardEditionisHighAvailability,which, asdiscussedinChapter5,combineswiththeVMFStoprovidecluster-likeservicesfor hostmachines.Ifonehostfails,alloftheVMsitwasmanagingareautomaticallyfailed overandrestartedonanotherhostinthecluster.VMsarerestartedbecausewhenthe originalhostfails,theyalsofailuntiltheyaremovedtoanotherhost.Notethatthis doesnotworklikethelivemigrationfeatureofVMware,whichmovestheVMwhile itisinoperation.
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Figure7-8. VMwareUpdateManagercanmanagehostsandVMs.
VI Enterprise provides organizations with the most advanced tools in support of thedynamicdatacenter.First,thiseditionaddsVMotion,thelivemigrationfeaturethat VMwarefirstmadefamous(seeFigure7-10).VMotionmovesVMcontentsfromone hosttoanotherwhilethemachineisinoperation.Forthistowork,yourhostsystems mustusethesameprocessorswiththesamesteppingorrelyontheEnhancedVMotion CompatibilityfeatureofESXServer,asdiscussedinChapter5. Inaddition,theEnterpriseEditionaddsStorageVMotion,whichissimilartoVMotion andwillworkinconjunctionwithittomoveaworkingVMfromonestoragecontainerto another(seeFigure7-11).Thecapabilitytomovevirtualmachinefilesfromonelocation totheotherinanondisruptivefashionliberatesadministratorsfromtraditionalshared storage constraints. This means that if you need to add additional shared storage to yourhostservers,youcanaddthenewcontainerswithoutimpairingVMoperation.
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Figure7-9. VMwareConsolidatedBackupcanbackuphosts,VMs,andinternaloperatingsystems.
Then, when you are ready to begin running VMs with this new storage, you can simplyuseStorageVMotiontomovetheirfilestothenewstorage.Thisletsorganizationsmanagestoragewithoutimpactingactualend-useroperations.Notethatunlike VMotion,StorageVMotiondoesnotrequireidenticalstoragecontainerstowork.
Figure7-10. VMwareVMotionatwork
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Figure7-11. VMwareStorageVMotionatwork
With these VMotion technologies, the Enterprise Edition of VI adds two powerful tools.DistributedResourceScheduler(DRS)letsyouassignresourcemanagementpoliciestoyourvirtualworkloads.BecauseVMwaresupportstheabilitytoassignresources toaVMthroughminimumandmaximumvalues,itcanconstantlymonitortherequirementsofaVMand,shouldtheVMrequiremoreresourcesthanareavailableonthehost, moveitthroughVMotiontoanotherhostserver.DRSregularlyscansVMsandhostserverstomaintaintheoptimumperformanceforeach(seeFigure7-12).DistributedPower Management(DPM)worksalongwithDRStomonitorhostserverrequirements.Should a host server not be required, it will automatically be moved to a power-saving state.
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Figure7-12. VMwareDistributedResourceScheduler
Then, when workloads increase and the system is needed to support them, DPM will poweritupandindicatetoDRSthatthenewhostserverisavailable.Thesetoolsintelligentlymonitordatacenterresourcesanddynamicallyturnthemonandoffinconjunction withbusinesscycles.Theyareatthecoreoftheconceptofadynamicdatacenter. WhilethethreepaidVIeditionsofferacomplementoftools,eachtoolisalsoavailableonastand-alonebasisandsomeareonlyavailableonastand-alonebasis.Forexample, Stage Manager and Lab Manager, two tools discussed in Chapter 6, are only availableasstand-alones.Youmust,however,havesomeversionofVIinplacetomake themostoftheseadditionaltools. VMwarealsooffersbundlesforsmalltomediumorganizations(seeTable7-2).These bundlescombineaseriesofdifferentcomponentsandprovidesupportforaminimum number of host servers. In addition, you can use VMware’s Total Cost of Operations (TCO)Calculator,mentionedinChapter5,toquantifythepotentialcostsavingsthatcan beobtainedthroughthepurchaseofVMwaresolutions. NOTE For more information onVMware’s scalable solutions, go to www.vmware.com/solutions/ smb/whats_new.html.ForaccesstotheVMwareTCOCalculator,gotowww.vmware.com/products/ vi/calculator.html.
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VMware Infrastructure Foundation
VMware Infrastructure StandardHA
VMware Infrastructure Midsize
VMware Infrastructure Enterprise
VirtualCenter Foundation+ 3VMware Infrastructure Foundation
VirtualCenter Foundation+ 2VMware Infrastructure Standard
VirtualCenter Foundation+ 3VMware Infrastructure Enterprise
VirtualCenter Management Server+ 4VMware Infrastructure Enterprise
Management VirtualCenter VirtualCenter VirtualCenter Solution Foundation Foundation Foundation
VirtualCenter Management Server
Description
VirtualCenter Foundation
✓ ®
✓ ®
✓ ®
✓ ®
ESXorESXi
✓ ®
✓ ®
✓ ®
✓ ®
VirtualSMP
✓ ®
✓ ®
✓ ®
✓ ®
VMFS
✓ ®
✓ ®
✓ ®
✓ ®
VirtualCenter Agent
✓ ®
✓ ®
✓ ®
✓ ®
Update Manager
✓ ®
✓ ®
✓ ®
✓ ®
Consolidated Backup
✓ ®
✓ ®
✓ ®
✓ ®
✓ ®
✓ ®
✓ ®
Storage VMotion
✓ ®
✓ ®
VMotion
✓ ®
✓ ®
Distributed Power Management
✓ ®
✓ ®
Distributed Resource Scheduler
✓ ®
✓ ®
High Availability
Table7-2. VMwareInfrastructureAccelerationKitsforSmallandMediumBusinesses
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Onceagain,eachbundleoffersavarietyofchoicesandtoolstoorganizationsofall sizes.Table7-3providesasummaryofthecapabilitiesofVMware’sVirtualInfrastructure components. NOTE FormoreinformationonVMwareInfrastructure,seewww.vmware.com/solutions/consolidation.
Tools
Description
VMwareConsolidated Backup
Performsvirtualandhostmachinebackups.
VMwareDPM
Dynamicallymanageshostserversbypowering themonoroffasneeded.
VMwareDRS
Monitorsutilizationacrossresourcepoolsand allocatesavailableresourcesamongthevirtual machinesonpre-definedrulesthatreflectbusiness needsandchangingpriorities.
VMwareESX
Hypervisorthatabstractsserverprocessor, memory,storage,andnetworkingresourcesinto multiplemachines.
VMwareESXi
Freehypervisorthatoffersthesamefunctionality asVMwareESX,butwithathin32-megabyte(MB) footprintdesignedforserverintegration.
VMwareHA
Provideshighavailabilityforanyapplication runninginavirtualmachine,regardlessofits operatingsystem(OS)orunderlyinghardware configuration.
VMwareLabManager
ManageseithersingleVMsorentireenvironments forthepurposeoftestingordevelopment.
VMwareLifecycle Manager
Managesvirtualmachineprovisioningfromstart toend.SupportssingleVMsorcompleteVM environments.
VMwareDistributed PowerManagement
Managespowerstatesforhostmachinesbasedon VMworkloadlowsandpeaks.
VMwareSiteRecovery Manager
Managesdisasterrecoveryscenariosfromsiteto siteintheeventofafullsitedisaster.
Table7-3. VMwareVirtualInfrastructureTools
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Tools
Description
VMwareStageManager
Managessolutionsastheyaredevelopedor preparedfromonestagingleveltoanother throughoutthesolutiongraduationprocessuntil solutionsarethoroughlytestedbeforeentering production.
VMwareStorageVMotion Enableslivemigrationofvirtualmachinedisk filesacrossstoragearrays.Allowsyoutorelocate VMdiskfilesbetweenandacrosssharedstorage locationswhilemaintainingcontinuousservice availabilityandcompletetransactionintegrity. VMwareUpdateManager ManagespatchesandupdatesofVMwareESX hosts,aswellasselectWindowsandLinuxvirtual machines. VMwareVirtualSMP
AllowsasingleVMtouseuptofourphysical processorsorprocessorcoressimultaneously.
VMwareVMotion
Movesrunningvirtualmachinesfromonephysical servertoanotherwithnoimpacttoendusers.
VMwareVMFS
SimplifiesVMprovisioningandadministration withahigh-performanceclusterfilesystem optimizedforVMs.Thisisthedefaultstorage systemforvirtualmachinefilesonphysicaldisks andpartitions.
VIToolkitforWindows
Providessupportfortaskautomationthrough theuseoftheWindowsPowerShellcommand language.Requiresthe.NETFrameworkto operate.
Table7-3. VMwareVirtualInfrastructureTools(continued)
Asyoucansee,VMwareoffersquiteafewtoolsinsupportofdynamicdatacenters. Itisnowonderthatmostofthedatacentersthathavealreadyimplementedservervirtualizationhavecometorelyonthistechnology.
CitrixVirtualizationTechnologies Citrixalsooffersseveraldifferenttoolsforitsvirtualizationengine.CitrixacquiredXenSource,themakersofXenServer,inlate2007andreliedonthisacquisitiontocreatethe basis of its virtualization offerings. XenSource was created as a company by bringing together several of the developers that worked on developing the Xen extensions for
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Linuxthroughanopen-sourceproject.ThesedeveloperswantedtotakeXentothenext levelbybringingadditionaltechnologiestotheforeandenhancingthecapabilitiesof theXenhypervisor. Terminal Services vendor Citrix bought into the hypervisor game by purchasing XenSourceandrebrandingitasitsown.ThisenabledCitrixtoenterthevirtualization fraywithfourkeyvirtualizationofferings.
▼ XenServerisitslineofhypervisorofferings.
■ XenDesktopisitssolutionforcentralizedvirtualdesktopmanagement.
■ XenApp(formerlyPresentationServer)isitssolutionforvirtualizingapplications.
▲ X enAppalsosupportsTerminalServicesandapplicationsharing,supporting itsPresentationVirtualizationofferings.
WhileitoffersafreeversionofXenServer,theExpressEdition,Citrixdoesnotofferany SoftV products, as all of its server virtualization offerings rely on HardV to operate. Therefore,itdiffersfrombothMicrosoftandVMwareinthisregard.Table7-4outlines theCitrixXenServerofferings.
Feature
Express
Standard
Enterprise
Platinum
Native64-bitXen hypervisor
X
X
X
X
WindowsandLinux guests
X
X
X
X
XenAPImanagementand controlscriptinginterface
X
X
X
X
XenCenterunified virtualization managementconsole
X
X
X
X
Multiservermanagement
X
X
X
SubscriptionAdvantage— firstyearincluded
X
X
X
VirtualLAN(VLAN) configuration
X
X
X
Resourcepools
X
X
XenMotionlivemigration
X
X
Table7-4. CitrixXenServerEditions
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Standard
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Enterprise
Platinum
SharedInternetProtocol (IP)-basedstorage
X
X
ResourceQualityof Service(QoS)controls
X
X
Dynamicprovisioning ofvirtualandphysical servers
X
Administrativemodel
Single server
Multiple servers
Multiple servers and resource pools
Multiple physicaland virtualservers andresource pools
Maximumphysical memory
128GB
128GB
128GB
128GB
CPUsockets
2
Unlimited Unlimited Unlimited
Guestsactive simultaneously
Unlimited Unlimited Unlimited Unlimited
MaximumRAMper virtualmachine
32GB
32GB
32GB
32GB
Table7-4. CitrixXenServerEditions(continued)
UnlikeVMware,Citrixdoesnotofferadditionalmanagementoroperationaltools alongwithitshypervisor(atleastnotatthetimeofthiswriting).However,Citrixhas announcedthatitwouldbeworkingonadditionaltools,especiallytoolsthatwouldsupporttheinteroperationandmanagementofvirtualmachinesacrossmultiplehypervisor platforms through known standards. It also announced that it intends to make these tools available for free. This is definitely something that you should look into as you reviewthecapabilitiesofdifferentvirtualizationengines. OnesignificantadvantageCitrixXenServerhadoverbothMicrosoftandVMware offerings was the ability to generate virtual machines as differentials from a core VM image.ThismeansthatinsteadofgeneratingVMs,whicharemultiplegigabytesinsize, youcanrelyonXenServertogeneratemachinesfromonesingleVMandonlycapture thedifferencesineachVMfile.Thissoftware-basedfeaturecansaveupto50percentof thestoragespaceyourequireforVMsandcanhaveapositiveimpactonyourstorage bottomline.VMwareaddedthisfeaturetoitslatestversionofESXServer.Microsoft, however,stilldoesnotsupportthisfeature.
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NOTE CitrixXenServerinformationisavailableatwww.citrix.com/xenserver.
MicrosoftVirtualizationTechnologies MicrosofthasbeenintheservervirtualizationbusinesseversinceitacquiredConnectix in2003.Atthetime,MicrosoftwaslookingtobuyVMware,butthedealwasnixedby itslegalteamonthegroundsthatifMicrosoftboughtVMware,itwouldbecomethe largestsingleownerofWindowslicensesintheworldbecause,atthetime,VMware sold virtual machines containing Windows operating systems as part of its product line.VMwarehassincestoppedreleasingvirtualappliancesprebundledwithWindows operatingsystems,butthatstillleftMicrosoftwiththeneedtoobtainavirtualization technologytobringitintoitssoftwareportfolio.ThisleftConnectix,theoriginalmakers ofVirtualPC. Connectix made the papers through the original release of virtualization software thatwouldletMacintoshusersrunWindowsapplicationsontheirsystems.Later,ConnectixportedtheirvirtualizationsoftwaretothePC.WhenMicrosoftacquiredConnectix,itfocusedonthePCversionofVirtualPCandquicklyturneditintotwoproducts: VirtualPCandVirtualServer.BothwereoftheSoftVvariety.Inaddition,VirtualServer requiredtheinstallationofInternetInformationServices(IIS)tooperatesinceitsmanagementinterfacewasWeb-based(seeFigure7-13).
Figure7-13. MicrosoftVirtualServercanrunmultiple32-bitVMs.
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Figure7-14. MicrosoftVirtualMachineManagerispartofSystemCenter.
MicrosoftlaterreleasedanintegratedversionofVirtualServeralongwithitsSystem CenterVirtualMachineManager(SCVMM),whichcouldbeusedtodeployVirtualServer withouttheIISrequirement(seeFigure7-14).In2008,aboutfour-and-a-halfmonthsafter releasingWindowsServer2008(WS08),MicrosoftreleasedHyper-V,aHardVhypervisor thatwasintegratedtotheWS08OS.ThisisMicrosoft’sflagshipvirtualizationtechnology (seeFigure7-15).Hyper-VcanrunoneithertheServerCore(recommended)ortheFull InstallationversionofWS08.Inaddition,theHyper-Vmanagementtoolscanbedeployed asstandalonetoolstomanagemultipleHyper-Vhosts.
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Figure7-15. MicrosoftWindowsServer2008canrunHyper-VineitherFullInstallation(shownhere) orServerCoremode.
Microsoft then adapted several of its existing management tools to interact and operatewithHyper-Vanditsothervirtualizationtechnologies.Table7-5outlinesthe Microsoftvirtualizationtoolset.
Tool
Purpose
MicrosoftApplication Virtualization (MSApp-V)
Virtualizesapplicationsanddeliversthemason-demand, streamingservicestodesktopusersandTerminalServices servers.Applicationsareavailablebothonlineandoffline. FormerlySoftGrid.
MicrosoftDesktop OptimizationPack (MDOP)forSoftware Assurance
LicensingschemethatprovidesadditionalresourcestoIT administratorsforthemanagementanddeploymentof desktopssolongastheyobtainSoftwareAssurancefortheir Microsoftproducts.IncludesMSApp-Vamongothertools.
Table7-5. MicrosoftVirtualizationToolset
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Purpose
OfflineVirtualMachine Supportstheconfigurationofupdatesonvirtual ServicingTool machinesthatarekeptinanofflinestate. SystemCenter Supportssystemdeployment,taskautomation,compliance ConfigurationManager management,andpolicy-basedsecuritymanagement. SystemCenterData ProtectionManager
LetsITadministratorsandendusersrecoverdataby deliveringcontinuousdataprotectionforMicrosoft applicationandfileservers.
SystemCenter Essentials
LetsITadministratorsmonitorandmanagesmaller environments.Managesbothvirtualandphysical machines.Managesupto500clientsand30servers.
SystemCenter OperationsManager
Monitorsenvironments,applications,andclients toprovideacompleteviewofthehealthofyourIT environmentandtoenablerapidresponsetoevents.
SystemCenterVirtual MachineManager
Enablestheincreaseofphysicalserverutilization;provisions andcentralizesmanagementofvirtualmachines.Supports themanagementofHyper-V,VirtualServer,andVMware ESX.CitrixXenServersupportisintheworks.Canalso convertphysicalserverstovirtualmachines.
TerminalServices
Virtualizesthepresentationofentiredesktopsorspecific applications(onlyinWS08).Localandremoteusersmust beonlinetoaccessTerminalServices.
VirtualPC
Designedtohostlegacyline-of-business(LOB) applicationsandapplicationsthatarenotcompatible withagivendesktopOS.
VirtualServer
SoftVenginethatcanbeusedtovirtualize32-bit workloads.Runsonboth32-bitand64-bithardware.
WindowsServer2008 Hyper-V
HardVenginethatisintegratedtotheWS08OS.Runsboth 32-bitand64-bitworkloads,butrunsonlyonx64hardware.
WindowsUnifiedData Networkattachedstorageenginethatcaneitherbeused StorageServer toprovidestorageservicesorasafront-endvirtual storagemanagerforstorageareanetworks.Alsosupports virtualharddrivesasiSCSItargets,lettingyoucluster virtualmachines. WindowsVista EnterpriseCentralized Desktop
Licensingschemethatsupportsthecentralizationof Windowsdesktops.LicenseisforVista,butsupportsany WindowsdesktopOS.Usersareallowedtorunuptofour virtualmachineseachwiththesameVistalicense.
Table7-5. MicrosoftVirtualizationToolset(continued)
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NOTE Microsoft virtualization information can be found at www.microsoft.com/virtualization/ products.mspx. Microsofthasbeenworkingatintegratingitsmanagementstrategiesforsometime andbecauseofthis,hasbeenabletorampuprapidlytoprovideextensivevirtualization managementtools.Assuch,itprovidesacomprehensiveapproachtovirtualizationfor bothitsownandotherhypervisors(seeFigure7-16).
VirtualMachineFormats OneofthechallengesITadministratorsfacewhentheyareimplementingvirtualization, especiallyiftheyimplementmorethanonehypervisor,isthevirtualmachineformat.As outlined in Chapter 2, several different files make up virtual machines—configuration, disks,in-memorycontents,logfiles,andmore.However,eachvirtualizationenginehasa tendencytoincludeitsownformatforthesefiles.Forexample,MicrosoftusestheVHDformatforharddiskdrives,whileVMwareusestheVirtualMachineDisk(VMDK)format. Inordertofosterasinglestandardforvirtualmachines,VMwareworkedwiththeIT industrytointroducetheOpenVirtualizationFormat(OVF).OVFhasbeenacceptedby theDesktopManagementTaskForce(DMTF),andseveralvendorsaremovingforward withthisformat.Forexample,asmentionedpreviously,Citrixisoneofthefirstvendors todevelopanOVFmanagementtool.VMwarealsohasavirtualmachineconversion tool,VMwareStudio,thatletsyoubundleavirtualmachineintoOVFformat. NOTE For more information on OVF and to access VMware’s OVF conversion tool, go to www.vmware.com/appliances/learn/ovf.html.
Figure7-16. Microsoft’svirtualizationstrategy
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OVFisasinglefileformatthatcanbeusedtobundleallofthefilesthatmakeupa virtualmachineintoasingle,transportableentity.Itcanalsobeusedtobundleaseriesof virtualmachinesintoasinglefile.Thismakesitusefulforthecreationnotonlyofsingle virtual machines containing virtual appliances, but also for the creation of entire computingenvironments,allbundledassinglefiles.OVFisbasedontheExtensibleMarkup Language(XML)standard.NotethatvirtualharddiskdrivesareconvertedduringthecreationofanOVFfileandconvertedbackwhentheOVFfileisimportedintoahypervisor. TheadvantagesofOVFare:
▼ I tsimplifiesdistributionofVMs.Itreliesonpublickeyinfrastructuresto providecontentverificationandintegrity.Inaddition,itprovidesabasic schemeforthemanagementofsoftwarelicenseswithinVMs.
■ D uringinstallation,OVFpackagecontentsarevalidated.Inaddition,theOVF standardcanincludeuser-orienteddocumentation,whichcanbeaccessed throughthevirtualizationengineimportingthefiletoprovideadditional implementationinstructionsforthepackagedcontent.
■ CanbeusedtopackagesingleormultipleVMsintoonesinglecontainer.
■ O VFishypervisor-neutral,supportingallcurrentvirtualdiskformats,making ittheidealformatformachinetransportation.Itisalsoextensibleandcan supportadditionalvirtualdiskformatsshouldtheyariseinthefuture.
■ V irtualappliances(VAP)—preconfiguredvirtualmachinescontaininga specificapplication—canbeconfiguredasOVFfilestomakethemavailableto anyhypervisor.VendorsonlyneedtoconfiguretheVAPonce.
■ T hedesignofOVFwasintentionallymadeextensibletosupportfutureusage ofVAPsandnewhypervisortechnologies.
■ O VFsupportslocalization,lettingvendorscreatelanguage-specificVAPsfor worldwidemarkets.
▲ O VFisanopenstandard,havingbeencreatedjointlybyvirtualization marketleadersand,assuch,itisnowundertheresponsibilityoftheDMTF, astandards-basedbody.
Inshort,OVFissimilartotheMicrosoftInstaller(MSI)formatMicrosoftusesforWindowsInstallerinstallationfiles.Ofcourse,theMSIformatisnotanopenstandard,but itisaspecialpackagingformatthatvendorsusetoprovidetheirapplicationstousersof Windows.WithOVF,vendorswilluseasimilarprocesstopackageready-to-runapplicationsintoastandardformat. Today,bothVMwareandCitrixoffersupportforOVF,whileMicrosoftintendsto addsupportforthisformatinfutureversionsofHyper-V.MachinesinOVFformatcan eitherbeimportedintoahypervisor,convertingthemtothehypervisorformat,orrun as-is.However,sinceOVFisaformatthatisdesignedtosupporttransportabilityandthe integrityofVMcontents,ifyourunamachineasanOVF,thesetwopurposesareinvalidated.OnceanOVFfilehasbeenmodifiedbyrunningitas-is,itcannolongerbeconsideredagoldenimageoftheVAPitincludes.Asyoucansee,OVFisonceagainsimilarto anMSI,sinceyoumustinstalltheMSIinordertousetheapplicationitcontains.
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NOTE The OVF specification is available at www.vmware.com/pdf/ovf_whitepaper_specification .pdf.ThisspecificationswhitepaperwaspublishedjointlybyVMwareandXenSource.
VMDiskTypes SinceOVFisbestusedtotransportVMs,youwillneedtounderstandandworkwiththe actualdiskformatssupportedbythehypervisoryouimplement.Table7-6outlinesthe differenttypesofdisksyoucanuseinservervirtualizationtechnologies. On high-performance storage volumes, you should aim to use dynamically expandingdisksasmuchaspossible;howevercertainworkloadswilloperatebetterwith fixed-sizedisks.AndasmentionedinChapter5,tyingadynamicallyexpandingdisk to virtualized storage using thin provisioning can save you considerable amounts of physicalharddrivespace.
VMDiskType
Format
Impact
Raw,Linkedor Pass-through
PhysicalDiskor Machineistiedtoa VMware, SANLUN physicaldiskdriveand Citrix, cannotbemovedfrom Microsoft sitetositeorclusterto cluster;however,tying themachinetoRAWdisks letsyoueasilyclusterit.
Dynamically Expanding
VHDorVMDK Diskexpandsasmachine needsmorespace. Diskfileonlycontains existinginformationand nothingmore.
Fixed-SizeDisk
VHDorVMDK Diskiscreatedwithaset VMware, sizewhenyoucreatethe Citrix, machine.Filemaycontain Microsoft considerableemptyspace.
Differencing Disk
VHD
Diskistiedtoanother parentorsourcedisk. Onlychangesarestored inthisdisktype(the child).Hassignificant performanceimpacts.
Table7-6. DiskFormatsSupportedbyVariousHypervisors
Manufacturer
VMware, Citrix, Microsoft
Citrix, Microsoft
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Virtualmachinedisksuseaflatfileformat,whichprovidesfastaccesstocontents. VMdisksareverymuchlikedatabasefilesandwilladdtothecontainerasnewdatais addedintheVM;however,theywillnotautomaticallyrecoverunusedspacewhenthe contentsaredeleted.Inordertorecoverunusedspace,youmustcompressanddefragmentthediskthroughspecialinterfaceswithintheVMmanagementtoolyouuse.For example,inWS08Hyper-V,diskmanagementisperformedbyeditingthepropertiesof adisk(seeFigure7-17),whileinVMware,itisperformedbyeditingthepropertiesofa virtualmachine(seeFigure7-18).Inbothcases,themachinemustbestoppedtobeable tocontroladisk’sproperties. Notethefollowingwhenworkingwithvirtualdiskdrives:
▼ V irtualharddiskscanalsobesettoundoabledisks.Inthiscase,theyareeither persistentornonpersistent.
■ U ndoabledisksaskifthechangesaretobesavedwhentheVMisclosed.If youwanttocommitthechanges,replyyes;ifnot,replynoandthemachine willreverttoitslastsavedstate.
Figure7-17. Hyper-Vdiskmanagement
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Figure7-18. VMwarediskmanagement
■ U ndoabledisksareanoldertechnology.Virtualizationenginesnowusedisk snapshotsinsteadofundoabledisks.
■ Snapshotscanbetakenatanytime,evenwhenthemachineisrunning.
■ Snapshotstakeanimageofthediskatthetimethesnapshotistaken.
■ S napshotsincludethein-memoryprocessesofthemachineaswellasthe settingsofthemachineatthetimeofthesnapshot.
■ W hensnapshotsaretaken,changesarestoredinlogfiles;thesefilescantake upalotofspacesincemosthypervisorssupportupto512snapshots.
▲ Y oucannottakeasnapshotofaphysicaldiskunlessyouhaveaccesstobuiltinsnapshottechnologies,suchastheVolumeShadowCopyService(VSS)in WindowsServerorthesimilarcapabilitiesofsharedstorage.
Snapshotsaremuchmoreusefulthanundoabledisks.Theyarealsousefulinlaboratory environments.Butinproductionenvironments,youmayprefertorelyonsnapshotsas aprotectionmechanismforthemachinesyouworkwith.Forexample,makeahabit oftakingasnapshotofamachinebeforeyouapplyupdatestoit.Iftheupdatesdonot work,reverttothesnapshotimageofthemachine.
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You’lllearnthatbecauseofthesefeatures,virtualharddiskdrivesaremuchmore practicalthanphysicaldrives.
VIRTUALIZATIONTECHNOLOGYPRICING Pricingisalwayssubjecttochange,andbecauseofthetypeofmarketvirtualizationvendorsarein,thecompetitionisfierce.Butasyoumakeyourchoicesforyourdatacenter, youmustatleastgainanideaofthecostsofeachtechnology.Table7-7listsasampleof thepricingforvariousproductsatthetimeofthiswriting.Whilethepriceswillmost likelybeconsiderablydifferentbythetimeyouhavethisbookinhand,thistablestillcan serveasaguidelineforwhattoexpectfromthethreemarketleaders.
Technology
Citrix
Microsoft
VMware
Hypervisor
CitrixXenServer EnterpriseEdition $2,000
Windows Server2008
ESXEnterprise EditionLicense $5,750
CitrixXenServer PerpetualServerwith Subscription$3,000 CitrixXenServer ExpressEditionfree download
Enterprise EditionLicense VMwareESXifree $2,500 download Microsoft VirtualServer freedownload
LiveMigration XenMotionLive Notapplicable; VMotionincluded Migrationonlywith usefailover intheEnterprise EnterpriseorPlatinum clustering Editionor$1,400 editions VirtualCenter ManagementServer onitsown$5,000 High Availability/ Clustering
Thirdparty,suchas SteelEyeProtection SuiteorMarathon Technologies
Included
Additionalcharges forDAS$2,000; includedinVI Standard
Dynamic Resource Management
Thirdparty,such asPlatformVM Orchestrator(VMO)
See Management
Additionalcharges forDRS$2,000; includedinVI Enterprise
Table7-7. Citrix,Microsoft,andVMwarePricingComparison
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Technology
Citrix
Management
Microsoft
VMware
SystemCenter Enterprise Edition$860
Additionalcharges $3,750;includedin VIFoundation
VMManager
VIEnterprise Configuration is$5,750plus VirtualCenter Manager Management DataProtection Server$5,000 Manager Operations Manager Capacity Planning
XenConvert
Includedin SCVMM
Additionalcharges forVMware CapacityPlanner
P2V/V2V
XenConvert
Includedin SCVMM
VMwareConverter included
Library
Included
Included
Included
Windows ServerGuest Licenses
WindowsServer EnterpriseEdition License$2,500
Included
WindowsServer EnterpriseEdition License$2,500
Windows Desktop
VistaEnterprise CentralizedDesktops (VECD)licensing required
VECDlicensing VECDlicensing required required
Table7-7. Citrix,Microsoft,andVMwarePricingComparison(continued)
Asyoucansee,eachofthevendorsrequiresdifferentcomponentstoprovideacompletevirtualandphysicalinfrastructuremanagementenvironment.Citrixreliesheavily onthird-partyproducts.Microsoftreliesheavilyonitsexistingmanagementtoolsfor Windowsenvironments.VMwarehasbeenworkingatcreatingacompleteVMmanagementsuiteforsometime. Inallcases,youwillneedMicrosoftWindowsServerlicensesifyoudecidetoruna Windowsinfrastructure.OneadvantageMicrosofthasisthatbybuyingtheWindows Serverlicense,youobtainalicensebothforthehostandforthevirtualmachines.Note, however,thattheVMlicensessupportedbytheWindowsServereditionarealsoavailableshouldyoudecidetouseanon-Microsofthypervisor(seeTable7-8).
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MicrosoftEdition
NumberofVM
WindowsServer2003R2/2008 StandardEdition
Rightstorunoneinstance
WindowsServer2003R2/2008 EnterpriseEdition
Rightstorunfourinstancesunderone physicallicense
WindowsServer2003R2/2008 DatacenterEdition
Unlimitedinstances Anyvirtualizationtechnologyorhost operatingsystem Perprocessorlicensing
Table7-8. NumberofVMsSupportedbytheWindowsServerLicense
Ifyouwantedalow-costenvironment,youcouldrelyonanyofthefreetechnologies fromCitrix,VMware,orMicrosoft.CitrixXenServerExpresswillonlysupportfourVMs perhost.VMwareESXiwillgiveyouallofthecapabilitiesoftheVMwarehypervisorfor free.AndMicrosoftVirtualServerwillalsorunseveralvirtualmachinesoneachhost, butitonlysupports32-bitvirtualmachines.Ineachcase,thefreetechnologiesonlyprovidetoolstomanageonesinglehostatatime.Whileitispossibletorunsmallshopsin thismanner,itiscumbersomeandwillnotbeefficientinthelongtermforanyonewith asignificantnumberofVMs.Inaddition,usingfreetechnologiesdoesnotprovideyou withsupport. But price alone is not enough to determine which technology you should rely on. Make sure you fully understand the capabilities of each environment and each toolbeforeyoumakethedecision.Forthisreason,thenextsection,“Market-Leader HypervisorMetrics,”willprovidevaluableinputtoyourdecisionsinceitcompares thefeaturesetsofeachhypervisorandoutlinesjustwhateachcandointermsofvirtualmachinesupport.
MARKET-LEADERHYPERVISORMETRICS Allhypervisorsarenotcreatedequal.Somearenativex64hypervisors,whileothersmay be32-bitbutincludex64componentsforimportanttasks,suchasmemorymanagement. Table7-9outlinessomeofthecoremetricsforeachofthethreemajorvendors.Usethis tabletodeterminehowmanyVMstorunperhostandhowtoconfigureyourhosts.Rely onthesevaluestomakeaninformeddecisiononhoweachhypervisorstacksupand whichoneyoushoulduseinyourownnetwork.
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Metric
VMware
Microsoft
Citrix
HypervisorOperationOverhead
Negligible OneCPUcore
OneCPU core
MaximumMemory(Host)
256GB
32GBto2 terabytes(TB)
128GB
RAMforHypervisor
32MB+
512MB+
256to 512MB+
MaximumCPUSockets(Host)
32cores
24cores
Unlimited
MaximumCPUSockets(Guest)
4
4
8
RequiredManagementNIC(s)
1
1
1
Maximumnumberofserversina poolorcluster
32
16
16
NumberofVMsperCPUCore
8to11
8
2to8
MaximumMemory(Guest)
64GB
64GB
32GB
SimultaneousActiveGuests/Host
192
192
Unlimited
Table7-9. Market-LeaderHypervisorMetrics
Table7-9requiressomecaveats.
▼ B ecauseVMwareusesanintegratedhypervisor,ESXi,whichhasaverysmall footprint,itsoverheadisnegligible.BothHyper-VandXenServerrequire 1CPUcoretooperatebecausetheyalsoincludeaparentpartitionwiththe hypervisor.
■ O fthethree,Hyper-Vsupportsthemosthostmemorybecauseitisbased onWindowsServercode.However,nophysicalhostwith2TBofRAM currentlyexists.
■ E achhostrequiressomeRAMforthehypervisoraswellassomeoverhead RAMforeachvirtualmachine.InthecaseofVMware,VMoverheadis30MB plus15%oftheRAMallocatedtoaVMforeachVM.Microsoftrequires32MB ofRAMforeachVM.CitrixcalculatesoverheadasapercentageofRAM.And, inordertolimitthehostserverRAMoverheadinHyper-V,youwouldwant tomakesureyouarerunningitonServerCoreonly,notthefullinstallationof WindowsServer2008.
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■ T hemaximumnumberofCPUsocketssupportedinhostserversiscalculated innumberoflogicalcores—normallyaphysicalcore—andaddressesthe maximumnumberofcoresincertainserverconfigurations.Notethat MicrosoftupdatedHyper-VonOctober24,2008tosupportupto24coresin supportofIntel’snewsix-coreprocessors.AndwhileXenServerstatesthatit supports‘unlimited’cores,thisisonlyafactoroftheEnterpriselicenseforthe product.Theactualnumberislimitedtophysicalboxconfigurations.
■ T hemaximumnumberofvirtualCPUcoresperguestisoftenafactorof theguestoperatingsystem.InVMware,mostguestoperatingsystemsthat supportmulti-processingwillsupportupto4virtualcores.Thesameapplies toXenServer,butitsguestoperatingsystemscanrunwithupto8virtualcores. InHyper-V,theonlymulti-processingOSthatwillrunwith4virtualcoresis WindowsServer2008.OthersupportedversionsofWindowsServerwillonly access2virtualcores.
■ EachhypervisorrequiresatleastonemanagementNIC.
■ P oolorclusternumbersarelimitedbythefunctionalityofthehypervisor. VMwaresupportspoolsthroughitsHighAvailability(HA)andVirtual MachineFileSystem(VMFS)features.Citrixhasabuilt-inresourcepool feature.MicrosoftreliesontheFailoverClusteringfeatureofWindowsServer 2008whichislimitedto16nodesinacluster,however,thesenodescaneither bewithinthesamesiteorinseparatesites.
■ E achhypervisorsupportsamaximumamountofRAMforguests,however,it israrethatorganizationsallocatethemaximumtoaguestOSsinceitdoesnot leavealotofmemoryforthehost.Allocatingthemaximumoftencreateswhat iscalleda‘single-VM’host—ahostthatrunsonlyonesingleVM—andthisis oftencostprohibitive.
▲ T henumberofvirtualprocessorcoresperlogical(readphysical)processorcore usuallyequatestothenumberofsinglevirtualprocessorcoreVMsyoucanrun onahost.Thisnumberisoftenlinkedtothefollowingvalue:SimultaneousActive Guests/Hosts.However,otherfactorssuchasavailableRAMlimitthepossible numberofVMsyoucanrun.CitrixXenServerhasbeenconfiguredwith32cores and50VMsinthepast.MicrosoftandVMwarehavenotannouncedhardlimits forthenumberofVMstheycanrun,butVMwarehasanedgeoverbothHyper-V andXenServerbecauseofitsmemorymanagementfeatureswhichneither oftheothertwohave.Becauseofthesefeatures,itispossibletoover-commit resourcestoVMsonanESXhostserver,assigningmoreresourcestotheVMs thanareactuallyavailableonthehost.VMwaresupportsVariableResourceVMs, whiletheothertwosupportonlyFixedResourceVMs.IntheFixedResourceVM model,thehardlimitfornumberofVMsismemory,notCPUcores.
Inactualfact,eachhypervisorhassimilarfeaturesasfarasthenumbersareconcerned. Butinreallife,organizationswillhaveatendencytorunmoreVMsinVMwarethanin theothertwoonsimilarhardwareconfigurations.Thisisbecauseoftheresourceovercommitmentfeaturesitsupports.Afterall,themainreasonwhyorganizationsmoveto virtualizationinthefirstplaceisbecausetheirphysicalserverresourcesareunderused
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mostofthetime.Socreatingavirtualmachinewithaminimumandmaximumresource settingmakesalotofsense—itrunswithminimalresourcesatlowloadsandusesmaximumresourcesduringpeakloads.However,forthistowork,youmustrunapoolof serverswithroomtospare.ThiswillletyoumoveaVMtoanotherhostserverwhenitrequiresmoreresourcesthanareavailableonthecurrenthost.Youwouldneedanadditional hostinyourresourcepoolanywaytosupporthighavailabilityforallofyourVMs. Inaddition,hostsupportfordifferentoperatingsystemswithinguestmachinesis notthesame.Table7-10liststheguestOSsupportforeachhypervisor.
Metric
VMware
GuestOS MicrosoftWindows Support 3.1/3.11/95/98/Me/ NT/2000/2003/2008/ XP/Vistax86orx64 MS-DOS6.x RedHatEnterprise Linux2.1/3/4/5 RedHatAdvanced Server2.1
Microsoft
Citrix
Microsoft Windows 2000/2003/ 2008/XPPro/ Vistax86andx64
MicrosoftWindows 2003SP2x64
SUSEEnterprise LinuxServer 10SP1
RedHatLinux 7.2/7.3/8.0/9.0
RedHatEnterprise Linux3.5/3.6/3.7/ 4.1/4.2/4.3/4.4/5 x86and5.0/5.1x64
SUSELinux 8.2/9.0/9.1/9.2/9.3 FreeBSD4.9/4.10/4.11/5.0 TurboLinux7.0,Enterprise Server/Workstation8
SUSEEnterprise LinuxServer9 SP2/9SP3/10SP1 32-bit
NovellLinuxDesktop9 SunJavaDesktop System2
DebianSarge3.1/ Etch4.032-bit
NetWare6.5/6.0/5.1 Solaris9/10forx86 Mostx64operating systems
CentOS 4.1/4.2/4.3/ 4.4/4.5/5.0/5.1x86 and5.0/5.1x64 OracleEnterprise Linux5.0/5.1x86 andx64
SUSELinuxEnterprise Server8/9/10
64-Bit Guest Support
MicrosoftWindows 2000SP4/2003/SBS 2003/2008/XP SP2/Vistax86
Windows64-bit operating systems
Table7-10. Market-LeaderHypervisorGuestOSSupport
Windows64-bit operatingsystems
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Onceagain,VMwaresupportsmanymoreguestoperatingsystemsthaneitherofthe other two 64-bit hypervisors. It also supports more x64 guest operating systems than theothertwo.Whilethismaynotbeimportanttoyou,youmustbeawareofthesefacts beforeyoucanmakeadecisiononwhichhypervisortoimplement.
Market-LeaderHypervisorPositioning Giventhefeaturesetofeachhypervisor,itisobviousthateachvendorhassomething tooffer.Microsoftoffersvirtualizationdemocratization.ByputtingtheirhypervisordirectlywithintheirOS,Microsoftgivesitscustomersaccesstoservervirtualization.Many shopswilloptforthistoolsimplybecauseitiseasytoaccess.Citrix,ontheotherhand, focuses on low-cost enterprise virtualization. However, shops using Citrix will often havetorelyonthird-partytoolstocreateacompletelydynamicdatacenter.Currently, VMwareisstillthemarketleader.Theirofferingsmayappeartobethemostexpensive, but their hypervisor offers more physical server density. If greening the datacenter is foremostonyourmind,VMwaremaybeyouronlychoicesinceitoffershighernumbers intermsofphysicalserverconsolidation. Thethreearethereforepositionedtogainsomelevelofmarketshareandcontinueto dosointhenearfuture.
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owthatyouunderstandthebasicfeaturesetsofeachhypervisor,you’reready to move on to working with the virtual machines themselves. To do so, you needtofirstunderstandhowthevirtualizationdecisionprocessshouldwork. Basically,thisprocessmatchesbusinessrequirementswiththetypeofvirtualizationthat meetsthembest.TheoverallvirtualizationdecisionprocesswasintroducedinChapter3, buthere,you’llfocusontheservervirtualizationcontentsofthisprocess. In addition, you need to understand the structure of the Virtual Service Offerings you will be running in the virtualization layer. How will you structure these virtual machines?HowwillyouassignVMpriorities,andwhichtypesofpoliciesshouldyou attachtoeachVM?Thesearedecisionsyoumustconsidernowbeforeyoubegintorun fullworkloadswithinthevirtuallayer. Finally,youneedtoconsiderhowyouallocateresourcestoyourVMs.Willacertain VMcontendforthesameresourcesasanother?Howwillyourhostserversdetermine howtoassignresourcestoeachVM,andhowwilltheydecidewheretoplaceaVM? Finally,howdoyouconfigurethehostsandjusthowmanyVMsshouldeachhostrun? Theanswerstothesequestionshelpyouunderstandhowvirtualworkloadsoperate andhowtobestusethephysicalresourcesyoumakeavailabletothem.
THESERVERVIRTUALIZATIONDECISIONPROCESS Thereasonwhyyouengageinvirtualizationis,ofcourse,tosaveonpower,cooling,space, and, of course, money. But even if you gain such powerful advantages by moving to a virtual infrastructure, your purpose is to continue and perhaps improve the way your datacenterrespondstobusinessrequirements.Asyou’veseensofar,workingwithvirtual machinesismuchfasterthanworkingwithphysicalmachines,yetyoumustbecarefulof VMsprawland,assuch,eachVMyoucreatemustmeetaspecificpurpose,and,ifpossible, betime-basedsothatitcanberemovedfromthedatacenteronceitspurposeiscomplete. Thebestwaytomanagethisprocessistorelyonagivendecisionprocess.Inthis case,itistheservervirtualizationdecisionprocess(seeFigure8-1).Youbeginbyfirst
Figure8-1. Theservervirtualizationdecisionprocess
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identifying the business requirement; then you determine if you will fulfill this businessrequirementontheserveroronthedesktop.Sinceyouarecurrentlyconsidering servervirtualizationrequirements,youknowthatinthiscase,youwillfulfillthebusinessneedsthatarisethroughservervirtualizationtechnologies. Next,youneedtodetermineiftherequirementisforatest,development,orproductionenvironment.Bothtestanddevelopmentrequirementswillbeaddressedinoneof threeways:
▼ W illyoubeusingadistributedsolution,onethatcouldberunningeitheron therequestor’sdesktoporonserverhardwarethatismanagedoutsideofthe datacenter?Ifso,youshouldrelyonfreevirtualizationtechnologiesand,most often,onsoftwarevirtualization(SoftV)products.Forexample,dependingon yourchoiceofhypervisor,youcoulduseVMwareServer,MicrosoftVirtual PC,orMicrosoftVirtualServertorespondtothisneed.Keepinmindthatthe Microsoftproductswill,ofcourse,producemachinesinthevirtualharddisks (VHD)format,butwillalsoonlysupport32-bitVMs.TheVMwaresolution, however,caneasilyruneither32-or64-bitVMssolongasithasbeeninstalled ontopofanx64operatingsystem.
achinesofthistypearebestpreparedcentrally,possiblythroughthevirtual M labyoucreatedinChapter6,anddistributedtoenduserswithaspecific servicelevel:Themachineisavailableas-isandwillbeprovidedagainas-is shouldanythinghappentoit.
nd,asdiscussedinChapter6,theidealconfigurationfortheworkstations A yourtestersanddeveloperswillworkonshouldbe:
■ Anadvancedworkstationwith4GBormoreofRAM
■ A separateexternalUSBdiskor,evenbetter,aseparateexternalserialadvanced technologyassessment(SATA)disk.RunningtheVMsonadiskthatisseparate fromthesystemvolumegivesmuchbetterperformance(seeFigure8-2).
Figure8-2. RunningVMsonaseparatediskgivesmuchbetterperformancefortestersanddevelopers.
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■ I fyourcustomerrequiresmoreadvancedfeaturesthanthefreeSoftVproducts offer,youmightconsiderprovidingthemwithapaidvirtualizationengine. VMwareWorkstation,forexample,istheflagshipSoftVproductfromVMware andincludespowerfulfeaturesthatarenotfoundinthefreeVMwareServer. Forexample,youcanuseVMwareWorkstationtorecordbothpictures andmoviesfromwithinvirtualmachinesdirectlythroughtheWorkstation interface(seeFigure8-3).ScreensarecapturedasBMPfiles,andmoviesare capturedasAVI.Moviecapturingwillevenomitblankscreensduringthe capture.Inaddition,usingtheTeamfeatureinWorkstationmakesitmuch easiertocreatecollectionsofVMsthatmaybelinkedtogetherformultitier applications.Forthesereasons,providingyourcustomerwithapaidcopy ofVMwareWorkstationwouldbestmeettheiradvancedrequirements.You should,ofcourse,useachargebacksystemtomakesuretheirproject’sbudget willpayforthisservice.
Figure8-3. CapturingamoviewithinVMwareWorkstation
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▲ I ftherequirementisforacomplextestingordevelopmentenvironment,such astheIntegrationorStaginglevelsdiscussedinChapter6,theonlysolution istoprovidethemwithremoteaccesstoahostedVMenvironment.Inthis case,youmayalsocalluponeitherVMwareLabManagerorVMwareStage Managertofurtherrefinetheserviceofferingyouaremakingavailable.
If the requirement is for a production solution, the answer is much simpler:You will providethecustomerwithacentrallyhostedVMorVMsthatwillbemanagedasproductionworkloadsonyourdatacenter’shypervisor.
VIRTUALSERVICEOFFERINGSSTRUCTURE Inproduction,you’llwanttoobtainthetopmostperformancefrombothhostsandvirtualmachines.Afterall,evenifyouwanttoimprovephysicalresourceutilization,you’ll stillwanttomakesureallsystemsperformattheirbest.Forthisreason,youneedtolook attheVirtualServiceOfferingsyouwillberunning.Thebestwaytodothisistotakea structuredapproach.BeginbycategorizingtheserverworkloadsinyourVirtualService Offerings.You’llfindthattherearegenerallyeightmainproductionservercategories (seeFigure8-4).You’llalsoneedtestsystemsanddevelopmentsystems,whichshould berunninginyourlaboratory,buteventhesefitintotheeightmaincategories. Asyoucansee,theeightcategoriesarebroughttogetherbygroupingservicetypes byserviceaffinity.Certaintypesofservicesorfunctionsdonotbelongtogether,while othersnaturallytendtofitinthesamecategory.Asaresult,youwillhaverolesthatare
Figure8-4. Theeightservercategories
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definedbythetypeofsoftwareserversrunandthetypeofservicetheydeliver.The resultingcategoriesinclude:
▼ Networkinfrastructureandphysicalservers Theseserversprovidecore networkingfunctions,suchasInternetProtocol(IP)addressing,forexample DynamicHostConfigurationProtocol(DHCP),ornameresolution,especially forlegacysystemssuchastheWindowsInternetNamingSystem(WINS). However,thisisnolongerreallyrequiredsincesingle-labelnamingisnow availablethroughtheDomainNameSystem(DNS)inWindowsServer2008. Theseserversalsoprovidevirtualprivatenetwork(VPN)andRoutingand RemoteAccessServices(RRAS).And,becausetheyareabase-levelservice, theyrunthevirtualizationroleonphysicalmachinesthroughtechnologies likehypervisors.
■ I dentitymanagementservers Theseserversarethecoreidentitymanagersfor thenetwork.Theycontainandmaintaintheentirecorporateidentitydatabase forallusersanduseraccess.ForWindowsServer2008(WS08),thesewouldbe serversrunningActiveDirectoryDomainServices(ADDS).Thisfunctionshould notbesharedwithanyotherasmuchaspossible,unlessitisacorenetworking function,suchasnameresolution—inthiscase,DNS.
■ F ileandprintservers Theseserversfocusontheprovisionofstorageand structureddocumentservicestothenetwork.TheyincludeboththeNetwork FileSystem(NFS)andtheCommonInternetFileSystem(CIFS).Theyalso includestandardandInternetprintservers.
■ A pplicationservers Theseserversprovideapplicationservicestotheuser community.WS08exampleswouldbee-mailsystemssuchasExchange Server,back-enddatabasessuchasSQLServer,andsoon—infact,any servicefromtheWindowsServersystem,includingmiddle-tiersystemsand failoverclusters.
■ T erminalservers Theseserversprovideacentralapplicationexecution environmenttousersthroughpresentationvirtualization.Usersneedonly haveaminimalinfrastructuretoaccesstheseserversbecausetheirentire executionenvironmentresidesontheserveritself.NotethattheRemote DesktopProtocolistheprotocolusedtoaccessallvirtualmachines.
■ D edicatedwebservers Theseserversfocusontheprovisionofwebservicesto usercommunities.TheyalsoincludeNetworkLoadBalancing(NLB)systems.
■ C ollaborationservers Theseserversprovidetheinfrastructurefor collaborationwithintheenterprise.Theirservicesincludecollaboration technologies,suchastheWindowsSharePointServices(WSS)ortheOffice SharePointServer,streamingmediaservices,andreal-timecommunications, suchasOfficeCommunicationsServer.
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▲ Failsafeservers Thiseighthrolefocusesonredundancyandprovides businesscontinuitybyhavingidenticalimagesofproductionservers instandbymode.Whenaproductionserverfails,thefailsafeversion automaticallycomesonline.Themostimportantaspectofthisserver constructionisreplicationtechnologies,ensuringthatfailsafeserversare alwaysup-to-dateandthatnodataislost.Thiscategoryisnowextremelyeasy tocreate,sincevirtualserversarenothingbutfilesthatneedtobereplicated inanotherlocation.Physicalserversarealsoeasytoreproduce,sincetheyrun onlyasingleroleandcancomewithanintegratedhypervisor.
Inaddition,serverplacementcomesintoplay.Placementreferstothearchitecturalproximityorpositionoftheserverinanend-to-enddistributedsystem.Threepositionsare possible:
▼ Insidetheintranet
■ I nthesecurityperimeter—oftenreferredtoasthedemilitarizedzone(DMZ), thoughforlargeorganizations,theperimeteroftenincludesmorethanjust aDMZ
▲ Outsidetheenterprise
Withthecomingofvirtualization,serverplacementtendstoblur,asvirtualmachineson aphysicalhostmaybeinonezone,whileothersonthesamehostareinanother.Make sureyoukeepserverplacementinmindwhenyoupositionthevirtualserversforeach zoneinyournetwork. NOTE For those running Windows workloads, Microsoft offers a Windows ServerVirtualization ValidationProgram.ThisprogramenablesvendorstovalidatevariousconfigurationssothatWindows Servercustomerscanreceivetechnicalsupportinvirtualizedenvironments.Customerswithvalidated solutionsbenefitfromMicrosoftsupportasapartoftheregularWindowsServertechnicalsupport framework.Tolearnmore,gotowww.windowsservercatalog.com/svvp. Ifyouplanwell,youshouldbeabletovirtualize100percentofyourworkloads.Today, virtualizationinfrastructurescanrunalmostanyworkload.InasurveyofVMwarecustomersconductedinJuly2007,VMwarefoundthatoutof361polledcustomers,mostof themranadvancedworkloadsontheirvirtualizationengine(seeFigure8-5). Thereshouldbefewreasonswhyyoucannotvirtualizeaserviceoffering.Forexample,youmaydecidetocontinuerunningsomeserviceofferingsonolder32-bithardware justbecauseyou’renotreadytomoveoffofthosesystems.Butconsidertheadvantages ofrunningvirtualmachines.Becausetheyarevirtual,theycanbeloadedonanyhardwaresystem.Inaddition,theyareeasytodeployandprotect—justcopythediskfilesto anotherlocation.
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Figure8-5. Commonvirtualworkloads
Anotherreasonformaintainingphysicalserviceofferingsmaybetouseolder32-bit hardwareinregions.Onceagain,youshouldruntheseasvirtualinstancesasmuchas possible.Ifyoudofindthatyouneedtomaintainolderhardwareandrunitinyour datacenter,whynotmakethemhostsystemsanyway?It’struethatHyper-Vdoesnot runon32-bitplatforms,butyoucanstillrelyontoolssuchasMicrosoftVirtualServer, SystemCenterVirtualMachineManager,orVMwareServer.Allwillrunon32-bitsystems,givingthemmorelifeasphysicalhostsinsteadofactuallydeliveringserviceofferingstousers.Thisway,allofyourphysicalmachines—32-and64-bit—arehosts,and allyourserviceofferingsarevirtualized.
VIRTUALRESOURCEALLOCATIONRULES Nowthatyouhavecategorizedthevariousserverworkloads,youneedtoconsiderhow youwillassignthemtohosts.Ifahostserverisgoingtorunupto20VMs,theVMscannotorshouldnotcontendforthesameresourcesatthesametime.Infact,youwantto configureheterogeneousvirtualworkloadsasmuchaspossibleandavoidconfiguring homogeneousworkloadsonhostservers.Todothis,youmustlookattheworkloads andidentifywhichprocessesandresourcestheyneedandwhentheyrequirethem.
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Forexample,ifyou’rerunningWindowsservicesinyournetwork,youcanexpect themtobehaveasfollows(seeFigure8-6):
▼ D omaincontrollers(DCs)requirenetworkandprocessorresourcesatpeak times(earlymorning,afterlunch).
■ F ileandprintserversrequireprocessorandnetworkresourcesatoff-peak times(mid-morning,mid-afternoon).
■ W ebserversfocusonnetworkresourcesand,ifproperlyconstructed,will requireasteadystreamofresources.
■ S QLServerandExchangeServerbothrequireasteadyamountofresources throughoutthedayandfocusmostlyondiskandprocessorresources.
■ Testanddevelopmentsystemsareoftenusedduringoff-hours.
▲ C orporateapplicationsoftenhavescheduledresourcerequirements.For example,apayrollapplicationwillrunonbimonthlyorbiweeklyschedules.
You’ll notice that not all workloads are busy at all times. In fact, some workloads are “parked”andrarelyrun.Thesearegoodcandidatesforrationalization. Becauseserverworkloadsrequiredifferentresourcesatdifferenttimes,youshould configureyourworkloadsinaheterogeneousmanner(seeFigure8-7).Thismeansone hostservercouldrunaDC,anetworkinfrastructureserver,afileserver,oneormore
Figure8-6. Serverresourcerequirementsovertime
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Figure8-7. Assigningheterogeneousworkloadstohostservers
webservers,testanddevelopmentservers,andperhapsevenacorporateapplication. Thekeyistofocusonworkloadsthatrequiredifferentresourcesatdifferenttimes. Ofcourse,ifyourunamonitoringtool,suchasVMware’sDistributedResource Scheduler(DRS),andassignappropriatepoliciestoyourVMs,thesystemwillautomaticallymovetheworkloadsfromonehosttoanotherinordertoguaranteethe required resource levels. Similarly, using a combination of System Center Virtual MachineManager(SCVMM),OperationsManager,andHyper-V,youcanrelyonthe Performance&ResourceOptimizationfeatureofSCVMMtooptimizetheplacement ofyourvirtualmachines.
RelyonPlacementRules Whenassigningworkloads,youneedtorelyonhostserverplacementrules.Forexample,eachtimeyoucreateavirtualmachineinMicrosoft’sSystemCenterVirtualMachine Manager,itreliesonplacementrulestoassignthenewVMtoahost(seeFigure8-8).
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Figure8-8. UsingmachineplacementrulesinVirtualMachineManager
Todoso,itassignsastarratingtoeachhostserver.Hostserverswithavailableresources aregranteduptofivestars,whilehostserverswithexistingworkloadsorwithfewer availableresourcesaregrantedfewerstars. Theseratingscanbecustomized.Bydefault,SCVMMreliesonloadbalancing,makingsureeachhostserverrunsapproximatelythesameamountofworkloadsor,atleast, usesupthesameamountofresources.Resourcesfocusonprocessor,memory,network, anddiskinputandoutput(seeFigure8-9).Youcanalsofocusonasecondplacement goal:resourcemaximization.Inthiscase,SCVMMwillcontinuetoassignVMstoahost untilallofahost’sresourcesareconsumed.
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Figure8-9. WorkingwithplacementoptionsinVirtualMachineManager
SCVMM also lets you customize host ratings by controlling just how much you expecttodrawfromahostserver’sCPU,diskI/O,andnetworkusage(seeFigure8-10). Usingtheseresourceassignmentsletsyoumaximizehowhostresourcesareconsumed byyoursystems.Thisishowyouguaranteethatyourphysicalserversrunworkloads thatuseupto80percentoftheircapabilities. Eachvirtualizationengineletsyoumanageresourcesinthismanner.Makesureyou work with your hypervisor management tool to properly configure and assign these resources.
SingleVersusMulti-VMHosts Whenorganizationsfirstbegantorunvirtualworkloads,theywantedtomaximizehardwareusage.Inaddition,inthefirstdaysofservervirtualization,hypervisortechnologies
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Figure8-10. CustomizinghostratingsinVirtualMachineManager
werevery,veryexpensive.Infact,manyvendors,suchasVirtualIronandXenSource (nowCitrix),madetheirentryintothehypervisormarketbyprovidinglessexpensive solutions.Now,withmanyhypervisorsavailableforfreeorforamerepittance,organizationsarelookingatservervirtualizationinadifferentlight. Before2007,organizationsonlyvirtualizedworkloadsthathadlow-resourcerequirementssothattheycouldloadupasmanyVMsaspossibleonahostservertomaximize theirinvestment.Today,withtheadventoflow-costvirtualization,youcanvirtualize anyworkload,evenworkloadsthatarehighlyresource-intensive.Whilepre-2007virtualizationfocusedonmulti-VMhostservers,today,youcanalsoconsiderthesingle-VM host(seeFigure8-11).Byvirtualizingworkloads,theybecomeliberatedfromthephysicalserver.Theycanthenbemoreeasilyprovisioned,protected,andmanaged.
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Figure8-11. Multi-VMversussingle-VMhosts
As a best practice, you should use the single-VM host to begin hosting resourceintensiveVMsandcloselymonitorhostresources.Ifresourceusageislessthananticipated,youcanaddmoreworkloadstothehost,maximizinghostusage.Inmanycases, server workloads will operate better and faster when virtualized, compared to their physicalcounterparts.VMwarewasthefirsttodemonstratethisatVMWorldEurope 2007whentheyshowedthatavirtualizedExchange2007Serverperformedbetterthan whenitwasphysicallyinstalledonthesamehardware.Forthisreason,therearevery few,ifany,workloadsthatyoucannotvirtualize.
WorkwiththeNetworkLayer As mentioned in Chapter 5, you can provision multiple virtual networks through the properties of the hypervisor. Three networks can be provisioned: public, private, and host-only.VMscanusethesedifferentnetworksinavarietyofwaysand,therefore,you shouldprovisioneachofthesenetworkswithinthehostsystemsyouprepare. Forexample,eachVMthatisdesignedtoprovideserviceofferingstoendusersmust do so through the public network. Therefore, these VMs must have at least one connection to the public virtual network interfaces you create on the host servers. Public networksalsoallowvirtualmachinesthatarelocatedondifferenthoststocommunicate witheachother.Itisagoodpracticetocreatemultiplepublicnetworkpathsoneachhost toprovideredundancyintheservices. Host-only virtual network cards are used to provision the VMs through the host. Forexample,ifyouneedtoupdatetheVM,youcandosothroughthehost-onlycommunicationchannel,avoidingadditionaltrafficonthepublicinterfaces.Host-onlycommunicationsareperformeddirectlyfromthehosttotheVMsandusethehost’sinternal communicationchannelstooperate.
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Privatevirtualnetworkcardscanalsobeusedtoavoidtrafficonthepublicinterface. Forexample,whenyoubuildafailovercluster,youmustcreateaprivatecommunicationchannelbetweenallofthenodesofthecluster.Thisprivatelinkisusedtoexchange heartbeatinformationbetweeneachnodeoftheclustertoensurethatthenodesdonot failoverunnecessarily.Byusingaprivatevirtualnetworkinterfacecard(NIC)forthis channel,yourelyontheinternalcapabilitiesofthehypervisortosupportthecommunication.Notethatwhenyouhostclusternodesontwodifferenthosts,youmustusea publicchannelforthiscommunication. AnotherexampleofprivatecommunicationsbetweenVMsisthecommunications betweenExchangeTransportServersanddomaincontrollers.AlloftheExchangeconfiguration is stored withinAD and is queried on a regular basis to provide Exchange with topology information. Directing this communication onto private networks will freeupthepublicnetworkforothertraffic. Forthisreason,youshouldprovisioneachhostwitheachnetworktypeandthenlink variousVMcomponentstotheappropriatevirtualNIC.
BESTPRACTICESINSERVERVIRTUALIZATION Asyoucansee,thereisalottoservervirtualization.You’llquicklylearnthatitisapowerfuloperationalmodelandthatthereturnoninvestmentisextremelyworthwhile.In addition,theadministrativeworkloadwilldecreaseandbecomemoreinteresting.There issomuchyoucandowithaVMthatyoujustcan’tdowithaphysicalserver. Remembertostandardizeallofyourhostserversasmuchaspossible.ChooseserversthatwillmeetandgrowwiththeneedsofyourVMs.Youmightconsiderputting yourvirtualizationmanagementsystemonaphysicalservertoensureconstantavailability.Ifnot,makesuretheVMthatincludesthistoolissettoautostartwiththehost serversothatyoucanquicklyandeasilygetintothemanagementenvironment. Configure your VMs with appropriate policies. For example, if you are running VMware,assignahighDistributedResourceSchedulingprioritytoapplicationsthat arehithardatspecifictimes.Also,makesureyourISOfilesareeasytoaccess.Itmight bebesttocreateacentrallibraryonafilesharetomakethemavailabletoanydevice andanymachine. Finally, pay close attention to Microsoft licensing. Virtual machines require fewer licensesthanphysicalmachines,andthisisoneofthereasonswhyitissorewardingto movetoadynamicdatacenter,butvirtualmachinesarealsoeasytogenerate.Keepthis inmindwheneveryoucreateanewVM.Youdon’twanttocauseproblemswithvirtualization;youaimtosolvethem.
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llmachineshavealifecycle,whethertheyarephysicalorvirtual.Thislifecycle ismadeupoffourphases,whichdifferslightlybetweenphysicalandvirtual machines.Inthedynamicdatacenter,physicalmachinesarehostserversonly,so theirlifecycleisgreatlyshortenedandsimplified.ButVirtualServiceOfferingscontinue torequireamoreextensivelifecycle(seeFigure9-1).
Figure9-1. Thefourphasesoftheservicelifecycle:planning,preparationanddeployment, production,andretirement
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Thislifecycleincludesfourdifferentstages,asfollows:
▼ Planning Identifyingandpreparingsolutionsfordeployment
■ P reparationandDeployment Acquiring,packaging,configuring,installing, andtestingdeploymentstrategies
■ P roduction Problem,change,optimization,andadministrationmanagement withintheproductionnetwork
▲ Retirement Replacement/upgradeplanningandremovalofobsolete technologiesandprocesses
Theplanningphaseisfocusedonidentifyingthebusinessrequirementandwhichtechnologieswillhelpfulfillit.Forvirtualmachines,thereisnoneedtopurchaseaphysical server,unless,ofcourse,therearenoexistinghostsforthisnewvirtualmachine(VM). Thisiswherehostserversmustbetransformedintosharedinfrastructurecosts.Because younolongerneedtopurchaseVMs,thepurchasingprocessturnsintoarequirements analysisprocess.Sincevirtualmachinesincludereducedlicensingcosts,provisioninga virtualinstanceofanoperatingsystem(OS)issimplerandeasierthanaphysicalinstance. Here,youneedtofocusonsystemrequirements—numberofprocessorcores,random accessmemory(RAM),diskspace,andnetworkinterfacesrequiredbytheVM—before youcreatetheinstanceoftheOS.Youmay,however,havetoobtainseparatelicensesfor theactualworkloadthemachinewillrun. NOTE This service-offering life cycle was originally presented in Windows Server 2003: Best PracticesforEnterprisesDeploymentsbyDanielleRuestandNelsonRuest(McGraw-Hill,2003).The modelwasderivedfromanoriginalmodelpresentedbyMicrosoftinawhitepaperentitled“Planning, Deploying,andManagingHighlyAvailableSolutions”releasedinMay1999.TheoriginalMicrosoft ITservicelifecyclemodelcanbefoundatwww.microsoft.com/technet/archive/ittasks/plan/sysplan/ availsol.mspx?mfr=true. Thepreparationanddeploymentphasefocusesonthetechnicalarchitectureprocess, whicheitherfollowsorcanoccuratthesametimeastheplanningprocess.Thetechnical architectureprovidesthespecifictechnicalparametersthatwillbeappliedtotheservice offeringduringitsinstallationandduringtherestofitslifecyclewithinthenetwork.It isbasedontheorientationsoutlinedinyourenterprisearchitectureandshoulddetailthe specificsoftheimplementation. Thelifecyclethenmovesontoinstallationandinitialconfigurationandpackaging/ staging.Packagingisusediftheserviceofferingreliesonasoftwareproductoranadditiontothecurrentnetwork.Stagingisusediftheservicereliesonafeatureofthenew operatingsystem.Forexample,withWindowsServer2008,youwillneedtorelyonboth packagingandstaging,sinceyouwillhaveatendencytobeginwithinitialinstallationor stagingofyourserversandthenfollowwiththeapplicationofthespecificfunctionorrole theserverwillplayinyournetwork.Packagingisoftenusedtoautomatethesoftwareor service-offeringinstallationprocess,oreventoturntheVMintoavirtualappliancethat canbeusedasasourceforother,similarrequirements.
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Testingisthenextstage,anditisvitalbecauseitensuresthestabilityofanynew serviceofferingintroducedintoyourproductionnetwork.Finally,theserviceofferingis readyfordeployment.Thisdeploymentcanbedoneinseveralstages.Anotherproofof concept(POC)canbeusedtoperformafinalvalidationoftheserviceofferinginoperation.ThetargetaudienceforthisPOCusuallyconsistsoftheprojectteamandsomeofits closestassociates.Thisisfollowedbyapilotprojectthattestsallaspectsofthedeploymentmethodology,includingtechnicalandadministrativeprocedures.Massivedeploymentfollowsasuccessfulpilotproject.Inaddition,theVMmustbeproperlypositioned onahostthathassufficientresourcestoruntheworkload.Atleastoneadditionalserver shouldbeearmarkedtoprovidefailoverforthisworkloadshouldeithermaintenanceor mishapsoccurontheoriginalhost. Oncetheserviceofferingisdeployed,itenterstheproductionphaseofitslifecycle. Here,youmanageandmaintainacompleteinventoryoftheservice,controlchanges, deal with problems, and support its users.You must implement and manage service level agreements (SLAs) for each service offering you deploy. SLAs focus on performance and capacity analysis, redundancy planning (backup, clustering, failsafe, and recoveryprocedures),availability,reliability,andresponsivenessoftheservice. ThefinalphaseoftheITservice-offeringlifecycleisretirement.Whentheservice reachesacertaindegreeofobsolescence,itmustberetiredfromthenetworkbecauseits operationcostsoftenoutweighitsbenefits.WithVMs,thisprocessiseasytoimplement andcanevenbeautomatedinsomeinstances. Workflowproductsareoftengoodtoolstousetoimplementthistypeofprovisioningprocess.Forexample,youcouldbuildsuchaprocessthroughtheWindowsWorkflowFoundationthatispartoftheMicrosoftOfficeSharePointSystem;oryoucould rely on VMware’s Lifecycle Manager, which includes built-in workflows for VM life cyclemanagement(seeFigure9-2).Asyoucansee,ittrackstheoriginalVMrequest
Figure9-2. VMwareLifecycleManagercanhelpmanagetheVMprovisioningprocess.
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frombeginningtoendandthenreliesontheplacementrulesyouhavedefinedtointelligentlyplacethemachineonthemostappropriatehost. YourelyonVMlifecyclestomakesurethatyoudonotproliferateserverVMs.Itis easytofallintotheVMsprawltrapsinceVMsaresoeasytocreate.Withastandardlife cycleprocess,youwillcontroltheurgetocreateVMsasneeded,oratleastgivethem time-basedpoliciessothattheywillautomaticallyberemovedfromthenetworkonce theyarenolongerrequired. CAUTION Inenvironmentswhereusershaveadministrativerightsontheirsystems,itiseasyfor themtodownloadandinstallafreeSoftVproductandbegintocreatetheirownVMs.Theproblemwith thisisnotsomuchthattheseusershaveaccesstoVMs,butmorethefactthattheyarenottrainedto properlyconfigurecomplexoperatingsystems.Inthiscase,itisbestforyoutocreatestandardVMs thatyoumakeavailabletothemonanas-neededandjustifiedbasis.Thisway,youwon’tfindoutthat youhaveroguesystemsrunninginunpatchedmodeinyournetwork. Oneofthemostimportantpartsofthefour-phaseVMlifecycleismachineprovisioning.Therearetwowaystoprovisionmachines.
▼ Provisionmachinesfromnewsourcetemplates
▲ Provisionmachinesthroughthephysicaltovirtual(P2V)conversionprocess
Eachprocesshasitsownparticularities.
BEFOREYOUBEGIN Yourgoalistotransformthephysicalmachinesinyourdatacenterintovirtualservice offerings.Buttoachievethisgoal,youneedtoknowwheretostart.Onegoodwayto dothisistorelyonSCOPE,aconceptualclassificationtool(seeFigure9-3).SCOPElets youquicklyidentifywhichworkloadstostartwith.SCOPEissimpletouse;itbegins withtheeasiestworkloadstoconvert,thenmovesupwardthroughthemostcomplex andcriticaltoyourbusiness. SCOPEdividesworkloadsasfollows:
▼ E asyworkloadsincludelabmachinesormachinesusedfortestand development.Trainingmachinesalsofitintothiscategory,aswellassystems runningWebservices,domaincontrollersinWindowsnetworks,andnetwork infrastructuresystemssuchasDHCPservers.Webserversareidealinthis categorybecausetheyoftenrunstatelessworkloadsorworkloadsthatare read-only.
■ P roductivityworkloadsincludesystemsthatrunprinters,fileshares, collaborationservicessuchasOfficeSharePointServerandotherserversthat actasfrontendston-tierapplications.Alsoincludedareanysystemsusedto shareapplicationscentrally,suchasTerminalServers.
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Figure9-3. TheSCOPECurvehelpsdeterminewhichserverstovirtualizefirst.
■ O perationalworkloadsincludeanysystemdesignedtomanageyour infrastructure.Theseareoftencompleximplementations,butarestillrelatively easytomigratebecausetheyoftenincludethecapabilityoftransferringarole fromoneservertoanother,makingthetransitionfromphysicaltovirtual— knownasP2V—simpler.
■ C omplexworkloadsincludesystemsthatrunhigh-availabilityorloadbalancingservices,aswellasthosethathavehighI/Othroughputs,suchas databases.Ifasystemisloadbalanced,migrationissimplifiedsinceyoucan addnewVMswiththeroleandintegratethemintotheloadbalancingcluster. Whenenoughmachineshavebeenvirtualized,youcandecommissionthe physicalnodes.
lusteredmachinesalsousethismodel.Forexample,withWindowsServer C 2008,youmustmigrateclustersfrompreviousversionsofWindowsServer. MigratingtoaclustermadeofVMsisjustaseasyasmigratingtoaphysical cluster.HighI/Oworkloadspresentatrickiermigration,butbythetimeyou gettotheseworkloads,youshouldbeveryfamiliarwiththecapabilityofyour virtualizationinfrastructureandwithVMsingeneral.
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▲ S pecialworkloadsarereservedforlast,givingyoutheopportunitytogain experienceintheprocess.Theseworkloadsareusuallyfewerinnumber andwillincludeitemssuchasbusinesscritical,manufacturingandlegacy applications.Hereyouhavetolooktospecialproceduresforvirtualizingthe workloadtomakesureitstillrunsproperlyonceconverted.
Atsomepointintime,you’llhittheValuetoBusinessBarometer—thepointatwhich conversiontakesmoreeffortthannormalandyoubegintowonderifit’sworthwhile. Wewouldarguethatconversionof100percentofyourinfrastructureisthegoal.Onceall systemsareconverted,you’llhaveatrulydynamicdatacenter;onewhereallenduserfacingworkloadsarevirtualized,andtheonlyrolehardwarehasinyournetworkisto actashostserversrunningvirtualworkloads. Nowyou’rereadytomoveontoprovisioningyourvirtualworkloads.
PROVISIONNEWVIRTUALMACHINES Whenyouprovisionvirtualmachines,youshouldcreatecustomtemplatesthatyoucan reuseoverandoveronanas-neededbasis.Inthephysicalworld,organizationsrelyon systemimagestosimplifymachineprovisioning.Inthevirtualworld,yourelyonaVM template.UsingVMtemplatesmakeslifesomuchsimplerbecauseallyouneedtodo tocreateanewVMiscopythefilesthatmakeitupandbootitup.Youmust,however, createstandardvirtualmachineconfigurations.Theseconfigurationsmustidentifythe followingitemsforeachVM:
▼ NumberofprocessorsorprocessorcoresperVM
■ AmountofRAMperVM
■ NumberofdisksanddiskspaceperVM
▲ Numberofnetworkinterfacecards(NICs)perVM
Overtime,youwillbeabletoextendthesestandardconfigurationstodifferentworkloads,knowingexactlyjusthowmanyresourcesyouneedtoassigntoeachservercategorytoprovideadequateservice—servicethatwillmeettheservicelevelagreements youhavesetwithyourusers. You must also identify how VMs are provisioned. If you don’t use a life cycle, as recommendedearlier,youhavetoimplementastandardrequestprocess.Thisprocess shouldhavetwoaspects:
▼ Administrative Requestorsofvirtualmachinesmustgothroughaprocess similartotherequestofaphysicalmachine.ThenewVMmustbecostedoutto theclient.Andyoumusthaveastipulationwithregardtoinfrastructurecosts. Whenanewhostoranewbladeenclosureisrequired,thecostmustbeborne bytheentireorganization,butsharedbyeachclient.
▲ Technical Youmustuseastandardmachinecreationprocess.Ideally,you willrelyonprecreatedvirtualmachinesasaseedfornewVMs.
ThisprocesswillhelpyoucontrolinternalVMsprawl.
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CreateSeedVirtualMachines Seed machines may not be simple to create, but in the virtual world, you only need to createthemonce.Whileyoureliedonsystemimagesinthephysicalworld,yourelyon virtualdiskdrivecopyinginthevirtualworldtoseednewmachines.Therefore,youmust createtherightsourcevirtualmachinesinordertoavoidpropagatinggarbageintothe network.Basically,yourseedmachineshouldbecreatedwiththesameprocessyouwould normallyusetocreateareferenceserverpriortogeneratingadiskimageoftheserver. Forexample,inaWindowsnetwork,youmightneedsourcesforseveraldifferent operatingsystemsand/orOSeditions,suchasthefollowing:
▼ WindowsServer2008(WS08)Standard,WS08Enterprise,WS08Web
■ WindowsServer2003(WS03)Standard,WS03Enterprise,WS03Web
■ Windows2000Server(W2K)Standard,Advanced
▲ WindowsNTServer(hopefullynot)
Ifyoucreatedasourcemachineforeachoftheseserveroperatingsystems,youwould need nine different seed machines, and this doesn’t even include any of the various Linuxdistributions.Forthisreason,itisagoodideatostandardizetheinfrastructure OSforVMs,reducingthenumberofserveroperatingsystemsthatarefoundinyour network.Onceagain,standardizationandrationalizationaretwocoreprocessesfound inanydynamicdatacenter. Youwillneedtwocopiesofeachsourcevirtualmachineyoucreate.Inthephysical world,youcreateareferencesystem,prepareitforduplication,andthencaptureasystem imagefromthereferencesystem.However,eachtimeyouneedtoupdatethereference system,youneedtoreapplythesystemimage,personalizethemachine,updateit,and repeattheentirepreparationprocessonceagain.Withvirtualmachines,yousimplykeep twoversionsofeachmachine:onethatisthereferencesystemandonethatisreadyfor duplication.ThesourceVMisusedtosupportmonthlypatchingandupdates,andthe SysPrepped,ordepersonalized,machineisusedtosupportmultimachineprovisioning. Makesureyouinjectvirtualmachinedriversintothemachine.Insomecases,theoperatingsystemshavebeen“enlightened”—thatis,theyhavebeenmadeawarethatthey are running in a virtual environment. These operating systems are intelligent enough tosharecoreresourcesandwillalreadyincludemanyoftherequireddriverstorun.In others,theyarestillstandardoperatingsystemsandmustbeinjectedwiththeappropriatedrivers.Duringthepreparationprocess,youwouldinstallcomponentssuchas VMware Tools, Hyper-V Integration Components, or other hypervisor components basedonwhichhypervisoryourun.
ProvisionUsingSeedMachines Whenyoursourceserversareready,youcanuseastandardprocesstoseednewVMs (seeFigure9-4).
1. KeepthereferenceVMsonstandbyuntilpatchesareneeded.
2. UpdatethesourcemachineeachPatchTuesday(monthly).
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Figure9-4. ManagingreferenceVMs
3. Inspectandcompressthevirtualdisk(s)thatmakeupthemachine.
4. R eapplySysPrepasneeded,suchaseachtimepatchesareappliedtothe referenceVMs.
5. CopyandrepersonalizetheSysPreppedVMtoprovisionanewsystem.
YoucanstandardizethisprocessanduseamonthlycycletoupdateyoursourceVMs12 timesperyear. Several tools will automatically update the source VMs. For example, Microsoft’s OfflineVirtualMachineServicingToolwillautomaticallylaunchshutdownVMs,patch them,andthenturnthemoffagainonaschedule.VMware’sUpdateManagerperforms asimilartaskusingasimilarprocess.LooktoyourhypervisortoolkittoreducetheoverheadofhavingtomanagemultipleVMimages.
PhysicalVersusVirtualProvisioning Asyoucansee,provisioningavirtualmachineismuchfasterthanworkingwithaphysicalmachine.Inthepast,youhadtobeginbyobtainingthehardwareforthenewserver, configureitonceitcamein,installtheOS,andtheninstallandconfiguretheapplication designedtoprovidetheexpectedworkload.Oncethiswasdone,youwouldtestthesystem,assignanInternetProtocol(IP)addresstoit,andpossiblyconfigurethenetworkto supportit.Thiscouldeasilytakeuptosixweeksbeforeasystemwouldbeready.Today, withtheproperseedmachines,youcanprovisionaservermuchfaster,sometimesinas littleas20minutes(seeFigure9-5). Thishasaseriousimpactontheamountofworkrequiredtocreatenewserviceofferings.Thisworkloadisreducedevenfurtherwhenyourelyonvirtualappliances.
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Figure9-5. Comparingthephysicaltothevirtualprovisioningprocess
RelyonVirtualAppliances Virtualappliances(VAPs)arevirtualmachinetemplates,sometimesintheOpenVirtualizationFormat(OVF),thatcontainpreconfiguredoperatingsystemsandapplications. SinceVMsareself-containedandtransportable,theycanbedeliveredinapreconfigured stateasvirtualappliances.VAPsaremostoftendesignedtorunonLinuxoperatingsystemsbecauseofthelicensingcost.FewvendorshavecreatedVAPsbasedonMicrosoft technologiesbecausetheyhavetobecomeWindowsresellerstodoso. However,VAPSfurtherdecreasethetimetoproductionofanewapplicationbecause theyarepreconfiguredandreadytorun.Giventhis,youmayneverneedtoinstallanotherproductagain;justgetitinaVAPandrunit. Virtualappliancesofferseveralbenefits.PhysicalITapplianceshavebeenaroundfor quitesometime.Severaldifferenttypesofappliancesareavailable:networkintrusion detectionsystems,searchengines,firewalls,storageservers,configurationmanagement servers,NetworkLoadBalancingservers,andmuchmore.What’sgreataboutthesedevicesisthattheyarereallyeasytodeployanduse;mountitinarack,giveitanIPaddress,andthenlogintoittoconfigureit—aprocessthatismuchlikethatofahostserver with an integrated hypervisor. Configuration is usually performed in a web interface throughabrowser:UsetheIPaddressyouassignedthedevicetogototheconfiguration page,changeorassignanadministrativepassword,andmoveontotheconfigurationof thefeaturesincludedinthedevice. Virtualappliancesareeveneasiertosetupthanphysicalappliances.Copythefiles thatmakeuptheVAPintoafilefolderonaserver,orimportthemiftheyareinOVF form,andthenlaunchthevirtualmachinethatmakesuptheappliancetofinalizethe
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configuration.Buteveniftheyareeasytosetupandinstall,yourvirtualappliancesstill needtobepreparedcarefully.Inthephysicalworld,yourmainconcernisiftheappliance willfitintoyourracks.Butinthevirtualworld,youmustensurethevirtualappliance youobtainreliesonthevirtualizationtechnologyyouhavedecidedtodeployinyour network.Forexample,ifyouchosetostandardizewithVMwareasyourvirtualization providerandthevirtualapplianceyouselectcomesinanotherformat,you’llmostlikely choosenottoobtainit.Afterall,youdon’twanttorunmultiplevirtualizationengines ifyoucanhelpit.Ofcourse,youcouldalwaysconverttheappliance,butdoingsomay wellvoidanywarrantiesprovidedbythemanufacturerbecauseyou’llbechangingthe verynatureoftheVM,unless,ofcourse,itispackagedwithOVF,whichisdesignedto supportthecreationofVAPsforanyhypervisor. In addition, when you rely on an appliance that is provided to you through a trustedmanufacturer,youwon’thavetoworryaboutlicensingissuessincetheseconcernsarepartofthewarrantythemanufacturerprovideswiththeproduct.Youknow youcansafelydeploytheapplianceanduseitrisk-freebecausethemanufacturerwill havetakenanypotentiallicensingissuesintoconsiderationinthefabricationofthe appliance. Anotherissueyoufacewithanyproduct,serverornot,istheupdatingprocess. Whenyouobtainandinstallyourowntools,youalsohavetodeviseastrategyofyour owntokeepthemup-to-dateintermsofpatchesandservicepacks.Withacommercial appliance,youdon’tneedtoworryabouttheseupdatesbecausetheyarepartandparceloftheapplianceitselfandthesupportprogramthatcomeswithit.Ofcourse,you havetomakesureyoucansupporttheupdateprocess,butyoudon’thavetodevise ityourself. KeepthefollowingconsiderationsinmindwhenyouselectacommercialVAP:
1. Isthevirtualappliancefullyconfiguredandsecured?
■ D oesitincludeaminimalistversionoftheoperatingsystem,includingonly thosecomponentsrequiredtosupporttheapplication,ordoesitinclude additional,unusedcomponents?
■ I stheoperatingsystemhardenedand,ifso,howisthishardening documented?
■ I stheoperatingsystemup-to-dateanddoesitincludethelatestpatchesand updates?
■ W hatothersecuritymeasureshasthemanufacturerappliedtothe appliance?
2. Whatarethevendor’supdateandupgradepolicies?
■ Doesthevendorhaveadocumentedupdateandupgradepolicy?
■ D ovendorupdatesaddressonlytheapplicationwithintheappliance,ordo theyalsoaddresstheunderlyingoperatingsystem?
■ Whatisthevendor’supdatescheduleandhowareupdatenotificationssent?
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■ A reupdatesincludedaspartofthesupportcostsfortheappliance,oris thereanadditionalcost?
■ A rethereanyimpacts,licensingoroperational,whentheVAPismoved fromonehosttotheother?
■ W hatistheimpact,costorotherwise,ofcreatingvirtualmachinesnapshots oftheVAP?
■ IstheVAPcertifiedbythevirtualizationvendoryouhaveselectedtouse?
■ I sitpossibletorecoverexistingconfigurationandmanagementdataduring theupgradeprocess?
■ W hatistheupgradeprocess?Canitbeassimpleasimplementinganew VAP,synchronizingdata,anddeletingtheoldVAP?
3. Whatisthevendor’spreferreddeploymentprocess?
■ WhichoptionsdoesthevendorofferforVAPevaluation?
■ WhataretherequirementsforanevaluationandtestoftheVAP?
■ Whatisthedurationofanevaluationperiodfortheproduct?
■ I sitpossibletoretaindatageneratedduringtheevaluationperiodwhen youmovetheVAPtoproduction?
■ H owdoyoumovefromevaluationtoproduction?Canitbeassimpleas enteringavalidlicensekeyintotheVAP?
4. Whatifyouneedtoscaleyourdeployment?
■ W hichoptionsdoesthevendorofferfortheimplementationofadditional VAPs?CanitbeassimpleasdeployingthesameVAPwithadifferent licensekey?
■ D oesthevendorofferasinglecentralizedconsolethatletsyouconfigure multipleVAPsinoneplace?
■ Isitpossibletosynchronizemultipleconfigurationswiththesamesettings?
■ Howdoesascaleddeploymentaffectlicensingandsupportcosts?
5. HoweasyisittomanageandmaintaintheVAP?
■ C anallVAPfeaturesbeaccessedviaasingleweb-basedinterface,oris consoleaccessrequired?
■ D oestheVAPhelpautomatecommonmaintenancetasks,suchasbackup anddiskdefragmentation?
■ DoestheVAPprovidealertsandnotificationsregardingitsstatus?
RelyingontheseconsiderationswillensurethatyouselecttheverybestVAP,aVAPthat willprovideoperationalsupportforaslongasyouneedit.
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VirtualApplianceBenefits Appliancesthatmeettheconsiderationsthathavebeenoutlinedearlierwillensurethat organizationscanquicklyrealizethemanybenefitsofVAPs.
▼ RapidDeployment Oneofthebiggestbenefitsofanapplianceisthatyou donotneedtorunthroughtheinstallationprocessforthesoftwareitcontains. Justcompareanyappliancewithanyproductthatisavailablethrough traditionaldistributionmeans.Inaddition,virtualappliancesworkjustthe samewayasaphysicalappliance.Themajordifferenceisthattheycomeina softwareversioninsteadofasaphysicaldevice,makingthemeveneasierto deploy.Foradministratorswhowanttoreducethephysicalfootprintoftheir datacenter,thevirtualappliancemightmakemoresense.
■ E aseofUse Anothermajorbenefitofvirtualappliances,orappliancesin general,isthattheysaveenormousamountsoftime.Formid-marketIT professionals,systemmanagementappliances—physicalorvirtual—areamajor boonbecausetheyletyoucontrolchangeinyournetworkwithoutadding anysignificantworkload.Infact,theyoftenreduceyourworkloadsincethe appliancecanhelpcentralizeallmanagementandadministrativetasks.
■ B estPracticesandSecureConfigurations Inaddition,appliancesprovide youwithasecureimplementationbydefault.That’sbecauseappliancesare builtandconfiguredbythemanufactureroftheproduct.Whocoulddoit better?Themanufacturerknowstheinsandoutsoftheirproductandcan ensurethatallpreconfigurationsareperformedusingbestpractices.Ifthe manufacturercaninstallandconfiguretheproductandthendeliveritina preconfiguredstate,whyshouldyoubotherwiththehassleoftryingtofigure itoutyourself?Byrelyingonappliances,youmayneverhavetoinstallaserver productagain.Preconfigurationbythemanufactureralsoensuresasecureand bulletproofinstallationthatisreadytorunassoonasyouconnectit.
■ S upportability Sincethemanufacturercreatesandcontrolstheconfiguration oftheproduct,youcanbesurethateveryaspectofitwillbecompletely supported.Manufacturerscanprovidethislevelofsupportfortheirproducts becausetheyknowitwassetuprightinthefirstplace.
■ S calability Becauseoftheirvirtualnature,itbecomeseasytoupgradethe resourcesforavirtualappliance.Juststopthemachine;addmoreprocessors, moreRAMoradditionaldisks,andnetworkcards;andrestartitagain. Itwillautomaticallytakeadvantageofthenewresources.Justaddafew configurationchanges,suchasmappinganIPaddresstoanetworkinterface card,andit’sreadytogo.Insomecases,youdon’tevenneedtostopthe virtualappliancetoaddnewresources.Italldependsonthevirtualization engineyouuseandthetypeofresourceyouneedtoadd.
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■ T ransportability Virtualappliances,likevirtualmachines,runonphysical hostservers.Becauseofthis,theyaretransportableandcanbemovedfrom onehardwareresourcetoanother.Pausethemachine,moveit,andthenstartit upagain.Thismakesiteasytoprovidethevirtualappliancewiththeresources itrequiresduringpeakloads.Somevirtualizationinfrastructureswilleven movethevirtualmachineautomaticallybasedonasetofpolicies.
■ B usinessContinuity Hardwareresourcescanbelinkedtosharedstorage, andvirtualappliancescanbecontainedwithinthissharedstorage.When problemsarisewithahardwarehost,thevirtualapplianceisautomatically movedfromonehosttoanotherinaprocessthatistransparenttoendusers. SomevirtualizationinfrastructureswillevenmovetheVAPwithoutanyservice interruptions.Youcanalsousereplicationtechnologiestoreplicatethevirtual appliance’sdiskfilestoaremotelocationforlonger-termbusinesscontinuity.
■ D isasterRecovery Becauseofthenatureofvirtualmachines,VAPscanbe backeduponaconstantbasisthroughsnapshots,ortheabilitytocapturethe stateofavirtualmachineatagivenpointintime.Youcanthenreturntothese snapshotsifsomethinggoesawrywiththevirtualapplianceduringcritical maintenance,update,andpatchingprocesses.Thiscanimprovethereliability oftheVAP.
▲ Affordability Becausetheydonotrequirededicatedhardware,VAPscan bemuchmoreaffordable.Inaddition,itbecomessimpletodeployadditional versionsoftheVAP,providingscalabilitywhenworkloadsincrease.
VAPsarethewayofthefuture.Inashorttime,allapplicationswillbeprovidedasVAPs andyouwillnolongerhavetoworryaboutinstallingandconfiguringacomplexapplicationagain.
CreateVirtualAppliancesofYourOwn Asyousawearlier,VAPsaredownloadablewhenitcomestoopen-sourcesystems.But when it comes to Windows, few VAPs are available. Because of this, you must create yourownMicrosoftVAPs.TheprocessforcreatingyourownVAPsisverymuchlike thatofcreatingaseedmachinefornewVMs,exceptthatinadditiontoinstallingtheOS andconfiguringitforuse,youinstalltheapplicationbeforeyoudepersonalizethemachine.Withthisprocess,youcancreatequiteafewdifferenttypesofMicrosoftVAPs.
▼ WebserversrunningInternetInformationServer(IIS)
■ SQLServerback-enddatabaseservers
■ WindowsSharePointServicesfront-endservers
■ Streamingmediaservers
▲ DHCPserversandmore
Once the VAP is prepared, you use the same depersonalization process as with seed VMs;thenyoucopyandpersonalizetheVAPasneededwhenyoureuseit.
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NOTE Look up how to create a SQL Server VAP at http://itmanagement.earthweb.com/article .php/31771_3718566_2. KeepinmindthatyoucannotcreateaVAPforanythingthatmustbeinadomain first,forexample,domaincontrollers,someExchangeserverroles,andsoon.Because of the domain association, these workloads cannot be depersonalized and copied. Youshould,therefore,documentandautomatetheinstallationoftheserolesasmuch aspossible.
PERFORMPHYSICAL-TO-VIRTUALCONVERSIONS Thesecondmethodforthecreationofvirtualmachinesisthephysical-to-virtualconversion process. The P2V conversion process decouples and migrates a physical server’s operatingsystem,applications,anddatafromitsphysicalcontainertoavirtualmachine guest hosted on a virtualization platform. During the conversion process, drivers are convertedfromphysicaltovirtualandthemachineisadaptedtothehypervisor. TherearethreeP2Vmethods.
▼ ManualP2V Manuallycreateavirtualmachineandcopyallthefilesfrom theoperatingsystem,applications,anddatafromthesourcemachinetothe VM.ThisprocesshastheadvantageofrunningonanOSthatisoptimizedfor VMoperation.
■ S emi-automatedP2V Useatooltomovetheserversfromthephysical statetoavirtualmachine,suchasMicrosoft’sSystemCenterVirtualMachine ManagerorVMware’sfreeConverter.
▲ FullyautomatedP2V Useatoolthatmigratestheserveroverthenetwork withoutuserinteraction.Thereareseveralsuchtoolsonthemarket,suchas PlateSpinorVizioncore,whichallsupportVMware,Citrix,andMicrosoft platformsinadditiontothetoolsfromthevendor.
Ineachcase,youmustcarefullypreparethephysicalmachinebeforethetransformation.
P2VPreparationTasks AsmentionedinChapters1through5,youneedtofullyunderstandyourenvironment beforeyoubegintotransformitintoavirtualdatacenter.Then,youneedtoperforma cleanupoftheenvironmentasmuchaspossible.Forexample,youdon’twanttofind yourselfinthemidstofamassivefileserverconversiononlytodiscoverthat90percent ofthefilesontheserverhaven’tbeenaccessedinmonthsandarereadyforarchiving. UsethetheSCOPEcurvetobestdeterminewhichmachinesshouldbemigratedfirst. Alsorelyonmetricssuchashardwarerequirements,softwaredependencies,licensing requirements,andcurrentresourceutilizationratiostodoso. Migrationreliesheavilyonthenetworktomovethedatafromonemachinetothe other.Basically,themigrationprocesscopiesthecontentsofthephysicaldiskdrivesto virtualdiskdrives,buttodoso,allofthiscontentneedstomovethroughthenetwork.
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This may cause some downtime. While several technologies support live conversion fromP2V,inmostcases,youwillperformtheseconversionsofflineduringmaintenance periods.Youmayevenneedtoputinarequestforaspecialmigrationperiod,whichwill allowyoutomoveallofthetargetmachinestoVMs. Whenmachineshaveredundantservices,theriskofdowntimewillbeconsiderably less. For example, if you migrate a domain controller with its accompanying Domain NameSystem(DNS)service,youshouldnotexperienceanydowntimesinceyouwill mostlikelyhaveanotherDCinproductionthatcantaketheloadinthemeantime.Keep inmindthatthisstrategydoesnotworkfororganizationsthatuseall-in-oneservers, such as Microsoft Small Business Server (SBS). Since all server roles run on the same machine,virtualizingSBSwillmostcertainlycausesomedowntime. Alsomakesureyouarepreparedforthemigration.Doyouhaveenoughstorageto virtualizeallofthemachinesyouaretargeting?Youshouldbeusingstoragevirtualization with thin provisioning and target the creation of dynamically expanding virtual disksinordertominimizetherequiredamountofstorage.Willyournetworkbeable totaketheloadduringtheconversion?Ifyouareatpeakperformancetoday,addinga conversionworkloadmayoverlystressyournetwork. Finally,itisagoodideatocheckwithvendorstoseeiftheysupportvirtualizingtheir applications.Vendorsthatdonotsupportvirtualizationarebecomingrareindeed,unlike tenyearsago,butitisalwaysgoodtocheck.Forexample,vendorssuchasOraclesupportthevirtualizationoftheirapplications,butonlyontheirownvirtualizationplatform. Inothercases,somevendorswillofferabest-effortsupportpolicy.Microsoft,forexample,offersabest-effortpolicyforthesupportoftheirapplicationswithinnon-Microsoft virtualization environments. Other vendors may actually request that you convert the workloadbacktoaphysicalplatforminordertoprovideyouwithsupportforspecial problems.KeepthisinmindwhenyouchoosetheP2Vtoolyouwilluse.Becauseofthis, youshouldalsoconsiderthebenefitsofintegratingthebackuptoolyouselectwiththe abilitytoconvertmachinesfromonestatetoanother. NOTE Microsoft’s support policy is documented in Knowledge Base article number 897615 at http://support.microsoft.com/kb/897615. Physical-to-virtualconversionsareusuallystraightforward:Pointtoaphysicalserver andtransformitintoavirtualmachine.Ofcourse,thetoolyouusetocarryoutaP2V conversion must support the transformation of the drivers that were included in the physicalinstallationoftheoperatingsystemtothoserequiredforthevirtualmachine engineorhypervisoryouarerelyingon.Thisisusuallythemostdifficultaspectofaconversion.Youshouldalsoaimtobeabletoperformreverseconversions;insteadofgoing fromphysicaltovirtual,yougofromvirtualtophysical.Whiletheneedforthesereverse conversions will disappear with time, it may still be a necessity in the early stages of yourdynamicdatacenterimplementation. Because of this, you may need a tool that can not only perform P2V conversions, butalsoV2Pconversions.Then,perhapsthebeststrategyyoucanuseistocombinethe requirements for backup and restore with the requirements for machine conversions.
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Figure9-6. UsingbackuporimagingtoolsforP2V
When you think of it, a P2V conversion is really nothing more than a backup of the physical drives. Ideally, you can use a tool that backs up any machine—physical or virtual—thenstoresthisbackupinacentrallocation.Inthiscase,diskimagebackups areoftenthebest.Whenthetimecomestorestorethemachine,youcanmovetheimage fromthiscentralbackuplocationtoanypotentialtarget,onceagainphysicalorvirtual. ThekeyfeatureyouneedtoidentifyistheabilitytoupdateOSdriverswhentherestorationprocessisrun.Manysuchtoolswillbeabletopointtoacentraldriverstoretofirst obtainthemandtheninjectthemintotheimageasitisbeingrestored(seeFigure9-6). Fromthenon,thistoolwillcontinuetosupportbackups,restores,andconversionsfrom anymachine,whetheritbeintheresourcepoolorintheVirtualServiceOfferings. Severaltoolsonthemarketoffersupportforthis.Looktodisk-imagingvendorssuch asAcronis,whichofferstheTrueImagelineofproducts,orSymantec,whichoffersthe Ghostlineofproducts,toevaluatethebesttoolforyourneeds.
PerformtheP2V Whenyou’rereadytoperformtheactualP2Voperation,usethefollowingapproach:
1. Determinethevalidityofthecandidateformigration.
2. Clarifyvendorsupportforthevirtualworkload.
3. Considerlicensingcostsandmakeadjustmentsifnecessary.
4. IdentifytheappropriatehostfortheVM.
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5. IdentifyCPUandmemoryrequirementsfortheVM.
6. IdentifythestoragelocationfortheVM’sfiles.
7. I dentifynetworkrequirementsandmakesuretheappropriatevirtualNICsare availableonthehost.
8. IdentifythefailoverstrategyforthisVM.
9. U seastandardnamingstrategytodifferentiatethenewVirtualService Offeringfromthephysicalhostthatusedtoruntheworkload.
10. Scheduledowntimeinsupportofthemigration.
11. PrepareyourtestingplanforthenewVM.
12. Prepareago-liveplanfortheVMonceithaspassedalltests.
Select the appropriate candidates in order of importance. Begin with low-risk, nonbusiness-criticalworkloads,suchasthetestanddevelopmentenvironmentsyourun. ThiswillletyoulearntheinsandoutsoftheP2Vprocesswithoutanynegativeimpact tothebusiness.Webserversarealsooftengoodcandidatesforinitialconversions.If yourWebsiteisproperlysetup,youmayalreadyhaveredundantwebserversrunningthroughNetworkLoadBalancing.Havingredundantservicesreducestherisk, especially for your first P2V experiments. Then, move on to low-utilization systems that host less critical applications. Next, work on higher-utilization systems that are notcritical.Thiscouldincludeapplication-specificserversorrouting/virtualprivate network(VPN)servers. Migrateserversrunningcriticalworkloadslast.Bythen,youshouldbequitefamiliar withtheprocessandbereadyforanyeventuality.Thiswouldincludeapplicationssuch asExchange,SQLServer,andbusiness-criticalapplications. You’ll find that there are several products, both free and paid, that support the physical-to-virtualmoveprocess.Selecttheonethatbestfitsyourneeds.Someofthe mostpopularwaystoperformaP2Vconversioninclude:
▼ VMwareConverter
■ PlateSpinPowerConvert
■ Ultimate-P2Vplug-inforBartPE
▲ Microsoftconversiontools
Eachprovidesitsownfeaturesandperformancelevel.
WorkwithVMwareConverter VMwareConvertercomesintwoflavors:ConverterStarterandConverterEnterprise. Starterisafreeversionthatletsyouperformsingleconversionsonaone-by-onebasis. ConverterEnterprisesupportsbothonlinereal-timeandofflineconversions.ThedifferencesbetweenthetwotoolsareoutlinedinTable9-1. Thistoolcanberunonavarietyofhardwareandsupportsmostcommonlyused versionsofMicrosoftWindowsoperatingsystems.VMwareConvertercanconvertlocal
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Feature
VMwareConverterStarter
VMwareConverterEnterprise
Description
Freeproducttoconvert physicalmachinesinto virtualmachines
Enterprise-classproduct tomanageandautomate large-scaleconversions
Support
Tobepurchasedona per-incidentbasis
Includedinsupport forVirtualCenter ManagementServer
Target
Small-scale,single-server conversions
Large-scaleserver consolidationprojects
Quickbackup/clonesofa smallnumberofservers
Centralizedmanagement ofmultiplesimultaneous conversions
Hotcloning Included (convertphysical machineswhilethey arestillrunning)
Included
Coldcloning (usingabootCD)
Notapplicable
Included
Multiple simultaneous conversions
Notapplicable
Included
Localconversions
Included
Included
Remoteconversions
Includedfordestinations under:
Includedforall destinations,including VMwareESXandESXi
■ VMwareWorkstation ■ VMwareServer ■ VMwarePlayer ■ VMwareGSXServer Licensing
Nolicenserequired
Licensefileisrequiredfor Enterprisefeatures
Table9-1. AComparisonofVMwareConverterEditions
andremotephysicalmachinesintovirtualmachineswithoutanydisruptionordowntime(seeFigure9-7).Thistoolcanalsocompletemultipleconversionssimultaneously throughacentralizedmanagementconsoleandaconversionwizard.Notethatperformingseveralconversionsatonceputsaheavystrainonthenetwork.
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Figure9-7. VMwareConverterEnterpriseEdition
Convertercanalsobeusedtoconvertothervirtualmachineformats,suchasMicrosoft Virtual PC and Microsoft Virtual Server, or backup images of physical machines, suchasSymantecBackupExecSystemRecoveryorNortonGhost12,toVMwarevirtual machines.Thisprocessiscalledavirtualtovirtual(V2V)conversion.Moreover,itcan restoreVMwareConsolidatedBackup(VCB)imagesofvirtualmachinestorunningvirtualmachines,orcloneandbackupphysicalmachinestovirtualmachinesaspartofa disasterrecoveryplan. NOTE For more information on VMware Converter, see www.vmware.com/products/converter/ overview.html.
WorkwithPlateSpinPowerConvert For more comprehensive environments that may even be using multiple hypervisors, looktotoolssuchasPlateSpinPowerConvert.Thistoolcanmigrateandprotectworkloadsoverthenetworkbetweenphysicalservers,regardlessofplatformorvirtualhosts
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and image archives. It can remotely decouple workloads from the underlying server hardwareandstreamthemtoandfromanyphysicalandvirtualhostwithasimpledragand-dropoperation. Themovecanbedoneinanydirectionbetweenphysicalandvirtualhosts:physicalto-virtual(P2V),virtual-to-physical(V2P),virtualtovirtual(V2V),physical-to-physical (P2P),inandoutofimagingformat,andsoon.Thistoolsupportsanyvirtualengines: Citrix,Microsoft,orVMware.ItcanconvertMicrosoftWindowsserverandclientoperatingsystemsaswellasLinux.ItcaneventargetimagearchivesfromAcronisorSymantec, orbackupsolutionssuchasDouble-Take. NOTE For more information on PowerConvert, see www.platespin.com/products/powerconvert/ overview.aspx.
RelyontheUltimate-P2VPlug-inforBartPE BartPEisafreepre-executionenvironmentthatiscommonlyusedbyITadministrators andtechnicianstoreplaceDOSwhenworkingwithmachinesthathavenooperatingsysteminstalled.Ultimate-P2Visafreeplug-increatedbyQuiHong,ChrisHuss,andMike Laverick.Thisplug-inallowsyoutocloneaphysicalmachineintoavirtualmachineand performthesystemreconfigurationtasksrequiredtomakeitbootable.Itcomeswithtwo userguides.Thefirstoneexplainsthemanualcreationoftheplug-insanddrivers,and thesecondgivesyoualltheplug-insanddriversyoucandownload.Unzipthesedrivers andplug-instotheBartPEinstallationandbuildaCDreadytoworkwithUltimate-P2V. ThistoolsupportsbothVMwareandMicrosoftvirtualdiskformatsastargets,letting youconvertmachinesforusewithVMware,Citrix,orMicrosofthypervisors. NOTE FormoreinformationonUltimate-P2V,seewww.rtfm-ed.co.uk/?page_id=174.
MicrosoftConversionTools Microsoftalsooffersconversiontools.TheMicrosoftVirtualServer2005MigrationToolkit(VSMT)isafreedownloadthatallowsyoutoconvertphysicalmachinestoMicrosoft’svirtualmachineformat,VHD(virtualharddisks).Butyoucanimportthisformat intoVMwareServerorVMwareWorkstationsincebothtoolscanconvertVHDfilesto theVMwarevirtualmachinedisks(VMDK)format. InordertobeabletousetheVSMT,youneedaccesstotheWindowsServer2003 AutomatedDeploymentServices(ADS),whichisalsofreebutcanberunonlyonWindowsServer2003EnterpriseEdition.Ofcourse,thistoolisdesignedtoconvertMicrosoft workloadsintovirtualmachines. NOTE For more information on the VSMT tool, see www.microsoft.com/technet/virtualserver/ downloads/default.mspx.
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MicrosoftalsosupportsP2VconversionswithSystemCenterVirtualMachineManager(SCVMM)throughawizardinterface(seeFigure9-8).However,foryoutobeable toperformconversionswithSCVMM,youmustalsohaveaccesstotheWindowsAutomatedInstallationKit(WAIK)becauseSCVMMreliesonWindowsPE—includedinthe WAIK—toboottoanalternateOSbeforecopyingtheservercontentstoavirtualhard drive.SCVMMconversiondoesnotworkwithallversionsofWindows.Inaddition,the machinemustbereachablethroughDNSoryoumustuseitsIPaddressforSCVMMto locateit.Basically,thewizardlocatesthemachine,gathersinformationaboutit,letsyou renametheVMifneedbe,letsyouconfigurevirtualdiskvolumes,letsyouselectthe targethostandpathforthenewVM,andfinallyletsyouassignadditionalproperties totheVM.NotethatSCVMMisnotfreeandmustbeacquiredaspartofyourvirtual infrastructure. NOTE FormoreinformationonP2VwithSCVMM,gotohttp://technet.microsoft.com/en-us/library/ bb963740.aspx.
Figure9-8. ConvertingmachineswithSCVMM
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PROVISIONINGBESTPRACTICES Asyoucansee,therearealotofdifferentmethodsandtoolsyoucanuseforP2Vconversions.OneofthebestistocreateanewVMandeitherrestorethecontentsofaphysical serverintotheVMor,evenbetter,migratetheVM’sworkloadintothenewmachine. Migratingcontentsfromaphysicalservertoavirtualmachinemaybebestbecauseit letsyoubuildpristinemachinesthatarebasedonstandardconfigurationsandthenload themwiththeappropriateworkload.Severaltoolsexisttomigrateanythingfromfile serverstoExchangeworkloads. NOTE For a step-by-step guide outlining how to convert enterprise network workloads from thephysicaltothevirtualthroughworkloadmigrations,seeWindowsServer2008:TheComplete ReferencebyRuestandRuest(McGraw-Hill,2008). ConsideryourP2Vstrategycarefullybecauseyoudonotwanttoconvertmachines thatarenotrunningattheirverybest.WhentheVMsareinproduction,theywillbe sharingresources.ThereisnothingworsethanaVMthatisimproperlyconfiguredand beginstohogallofthehostserver’sresources.Youdon’twanttotransferproblemsfrom thephysicaltothevirtualworld.Inaddition,considerthefollowingbestpracticesbefore youperformaP2Vconversion:
▼ M akesureyoucanconverttothetargetmachine.Forexample,ifyouare runningMicrosoftVirtualServer,youcannotconvert64-bitmachines.
■ D etermineifyoucanperformanonlinemigrationbeforeyoubegin.Some workloadsdonotlendthemselvestoonlinemigrations.Insomeinstances, youmustperformthemigrationwhilethesource(physical)serverisoffline.
■ M akesurethehostsystemsincludeenoughspaceandresourcecapacityforthe conversion.Whenyouconvertasystem,youmusthavespacetohostarunning instanceplusspacetohosttheVMelsewhereinsupportofhighavailability.
■ P reparethesourceserverbeforeyouperformtheconversion.Performa checkdisktoidentifybadsectors.Performadefragmentationtospeedup theconversionprocess.Andusedynamicvirtualdiskstominimizespace.
▲ V erifythetargetserverafterthemigration.PerformapostP2Vcleanup.This cleanupincludesitemssuchasremovingallvendoragents,removingdrivers thatarenotusedinavirtualizedenvironment,andremovinganyunnecessary devices.
Usingthesepracticeswillhelpyoubuildthebestdynamicdatacenterandperform error-freeP2Vconversions.
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10 Work with Desktop Virtualization
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D
esktopshavebeenthebaneoftheadministrator’sexistenceeversincetheyfirst appeared on the market. Desktops are distributed points of access to system resources and as such must be standardized as much as possible to reduce potential issues. However, too many organizations do not lock down their desktops eveniftheydostandardizethem.Opendesktops,ordesktopswheretheenduserisa localadministrator,areimpossibletomanagesincetheychangefromtheverymoment they are deployed. In fact, they can be the cause for virtual machine (VM) sprawl, as usersthatarelocaladministratorscaneasilyinstallvirtualmachinesoftwareandbegin creatingtheirownVMs,causingevenmoreproblemsfordesktopadministratorsand technicians. Ifdesktopsarenotlockeddown,therecanbenocontrolandtherealwaysarealot ofissues.Yetitispossibletolockdownsystemsandstillallowthemtowork.Oneof ourcustomerslockeddowntheirdesktopswithWindowsNTin1996.Theresult:They reduceddesktop-relatedhelpdeskcallsby800percent!Ifitwaspossibleforthemtolock downthedesktopwithanarchaicoperatingsystemlikeWindowsNT,itispossiblefor everyoneelsetodoitwitheitherWindowsXPorWindowsVista,bothofwhichhave massive built-in improvements for just this issue. Yet administrators today still don’t bothereventryingbecauseitisjusttoomuchwork.Usershavebecomeusedtocontrollingeverythingontheirdesktop,andtheyjustwon’tgiveupthisfreedomsincethey nowconsideritanacquiredright. Theproblemhasalwaysstemmedfromtheverynameweusefordesktops:personal computers(PC).Insteadofpersonalcomputer,organizationsshouldmakeapointofcalling their systems professional computers. Using the term PC in its original sense gives everyusertheimpressionthatthecomputeristheirsinthefirstplace.Well,thatisnotthe case.Thecomputer,likethedeskitsitson,belongstotheorganization,nottheindividual, andbecauseofthis,itshouldbelockeddownandcontrolledcentrally.Thekeytosucha projectisthepropernegotiationofwhoownswhatonthePC.Wheredotheuser’srights beginandwheredotheyend?WhatbelongstothecorporationandwhatbelongstoIT? DefiningeachofthesepropertyzonesonthePCandmakingthemveryclearthrough massivecommunicationswiththeusermakesalocked-downprojectwork.
WORKWITHASYSTEMSTACK AnothermajorproblemofdistributedPCsistheamountofapplicationstomanageand deploytothem.Whileorganizationsrangeinsizeandnumberofusers,theyareusually ratherconstantinthenumberofapplicationstheyrunonaper-userbasis.Intheworst case,theymanagemorethanoneapplicationperuser;inthebest,theyhavelessthan oneperuser,butwhenyouthinkthatanorganizationwith1,000userscanhavetomanage1,000ormoreapplications,youknowandprobablysharetheirpain.Onethousand applications to package, deploy, update, license, monitor, and support. That’s a lot of work. What is worse is trying to get the applications to coexist properly on the same system.Nowthatisachallenge.
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Thisiswhyyouneedtocreateastandardsystemstack.UsingasystemstacksimplifiesthewayyouconstructPCsaswellasthewayyoumanageapplicationsbecauseit structureshowcomputersystemsarebuiltfromthegroundup.Feworganizationswill everneedtoinstall200or500productsonthesamecomputer.Usingamodelforsystem designwillensurethatapplicationsarecategorizedproperlyandregroupedintofamiliesthatworktogethertoprovidethefunctionalityrequiredtofulfillspecificjobroles withinyourorganization.Forthisreason,wehavebeenpromotingthePointofAccess forSecureServices(PASS)modelformorethan15years(seeFigure10-1).Organizations relyingonthissystemstackhaveaproventrackrecordofpropersystemandapplication management.
Figure10-1. ThePASSsystemconstructionmodel
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Thissystemstackisbasedontheconstructionofacomputersystemthatrespondsto corporateneedsinthreeways:
▼ T hePASSsystem“kernel”isdesignedtomeettheneedsoftheaverageor genericuser.Itcontainsallofthesoftwarecomponentsrequiredtoperform basicofficeautomationandcollaborationtasks.Inaddition,itisdividedintoa seriesoflayerssimilartotheOpenSystemsInterconnection(OSI)networking model.LiketheOSImodel,itusessevenlayerstoprovidecorecorporate services.Becauseitsfunctionalitiesarerequiredbyallpersonnel,thiskernelis installedonallcomputersystems.
■ R ole-basedapplicationsandcommercialsoftwareareaddedontopofthe kerneltomeettherequirementsofthespecialITroleseverypersonplays withintheorganization.
▲ F inally,anadhoclayerrespondstohighlyspecializedITrequirementsthatare oftenexpressedonanindividualbasis.Thisadhoclayercanbeappliedatany timeandtraversestraditionalverticalITroles. NOTE InthePASSmodel,thekernelisconsideredaclosedcomponentthatisreproducedonall systems.Layersthatarelocatedbeyondthekernelareconsideredoptionalforallsystems.
ConstructingsystemsbasedonasystemstacksuchasthePASSmodelgreatlyreduces systemmanagementeffortsbecauseitreducesthenumberofprogramsthatmustcoexist onanysystem. First,agoodportionofsystems,sometimesupto50percentormore,willonlyrequirethesystemkernel.Rememberthatthekernelshouldcontaineverysingleprogram thatisroyalty-freeandrequiredbytheentireorganization(forexample,Adobe’sAcrobatReaderorthenewMicrosoftXPSDocumentReader);everyprogramthatismandatedbyinternalpolicies—antivirustools,forexample;andeveryprogramforwhich the organization obtains an enterprise-wide license (for example, many organizations obtainanenterpriselicenseforMicrosoftOffice). Second,bygroupingprogramsintorole-basedconfigurations,organizationsareable toreducethenumberofapplicationsthatmustcoexistonasystem.Role-basedconfigurationsincludeeveryprogramthatisrequiredbyeverymemberoftheITrolegrouping. Forexample,WebeditorswouldrequireaWebeditingtool,agraphicstool,aWeb-based animation tool, and other Web-specific utilities. This group of tools can be packaged separately,butshouldbedeliveredasasingleunitonallsystemsbelongingtotheIT role.Role-basedconfigurationsoftenincludenomorethan10to30individualprograms, dependingontherole.Onlythesegroupingsneedtobeverifiedwitheachotherand againstthecontentsofthesystemkernel.Thereisnorequirementtoverifyortestthecohabitationofprogramscontainedindifferentconfigurationsbecausetheyarenotlikely tocoexistonthesamesystem. Third,adhocprogramsreducesystemmanagementeffortsevenfurtherbecausethey areonlyrequiredbyafewusersintheorganization.Theyarestillpackagedtoenable
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centralized distribution and automated installation, but once again, they only require testingagainstboththekernelandtheconfigurationstheywillcoexistwith;however, becauseoftheiradhocnature,theymaycoexistwithallpossibleconfigurations. Eachapplicationhasalifecycleofitsownthatisindependentofitslocationwithin thesystemconstructionmodel.Thedifferenceliesintheratewithwhichyouapplylife cycleactivitiestotheapplication.Componentsofthekernelwillhaveanacceleratedlife cyclerate—sincetheyarelocatedonallsystems,theytendtoevolveatafasterpacethan othercomponentsbecausetheyaresupportedbycorporate-widefunding—whileproductswithintheouterlayersofthemodelwillhaveslowerlifecyclerates,whichwillbe fundedbythegroupsthatrequirethem.Ideally,therateofevolutionoftheseproducts willbemonitoredbythesubjectmatterexpertsorapplicationsponsorsyourorganizationidentifiesforeachnon-kernelapplication. NOTE Applicationsponsorsareresponsibleforseveralactivities,fourofwhicharesubjectmatter expertisefortheapplication;acceptancetestingforapplicationpackaging;applicationmonitoring,or watchingfornewversionsorpatches;andrationalizationjustifications,orjustifyingwhytheapplication shouldbeintheoverallsoftwareportfoliointhefirstplace. Usingthesestrategieswillreducetheoverallissuesyoufacewhenyoubuildand managedistributedsystems,buttheywillnotreducethemall.
DESKTOPMANAGEMENTISSUES Systems weren’t locked down and they were rarely standardized until organizations movedtoWindowsXP.ButgiventhatmostorganizationsrecentlyfinishedstandardizingonWindowsXP,aretheyreadytobeginagainjusttolockdowntheirsystems?The answerisno.AndthisisthesameanswerforamovetoVista.Performingamassivedistributeddesktopdeploymentisadauntingtask,mostlybecauseeachandeveryapplicationthatismanagedintheorganizationneedstoberevisitedtoverifycompatibility, possiblyupgradeit,repackageit,andthendeployitonthenewoperatingsystem(OS). That’sjustalotofworkforverylittleprofit.JustwhatisthestatusofVistadeployments today?Justwhatisadesktopanyway?Theanswerstothesequestionshelpunderstand themovetodesktopvirtualizationorthecreationofstandarddesktopimagesthatare runinsidevirtualizationsoftware,notonphysicalhardware.
VistaStateoftheUnion FeworganizationshavedeployedVistatodate,anddespiteMicrosoft’sbestefforts,that isunlikelytochangeuntilWindows7isreleased.Yet,accordingtoMicrosoft,Vistaisthe fastest-sellingoperatingsysteminthecompany’shistory.
▼ Morethan100millioncopiesweresoldbymid-2008.
■ In2008,2,500applicationswerecertifiedforVista,comparedto254in2006.
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■ Ninety-eightof100ofthebest-sellingapplicationsareonVistatoday.
■ Onehundredfiftyenterprise-classapplicationsareavailabletorunonVista.
▲ In2008,78,000deviceswerecertifiedfordeploymentwithVista.
Giventhesestatistics,youwouldthinkthatVistaisthemostpopularOSMicrosofthas releasedinquiteawhile,butthatdoesnotseemtobethecase—oratleastthatiswhat seemstocomeoutofasurveyperformedbyKaceSystemsinmid-2008.
▼ N inetypercentofadministratorsareconcernedaboutVista,butonly13percent haddefiniteplansinregardtoVistadeployment.
▲ F orty-fourpercentwereconsideringanotherOS,butmorethan50percent oftheseweresayingthatsystemmanagementissueswithotheroperating systemswerestoppingthemfromdoingso.
However,whetheritiswithVistaoranyotherdesktopoperatingsystem,distributed desktopsarehardtomanage,period.Theyaredistributedthroughouttheorganization’s office.Theycanbedesktopsormobilesystems.Theycanbeinsidetheofficeoroutside theoffice.And,ofcourse,whenusershaveadministrativerights,youneverknowwhat thestatusofyourOSisassoonasitleavesyourdesk. NOTE IfyouareoneoftheveryfewwhoareactuallydeployingVista,turntotwobooksforhelp: thefreeDefinitiveGuideforVistaMigrationbyRuestandRuest,whichcanbeobtainedatwww.altiris .com/campaigns/vista/vista_ebook.aspx,andtheDeployingandAdministeringWindowsVistaBible byKelly,Ruest,andRuest(Wiley,2008).
TheAnatomyofaDesktop Whenitcomesrightdowntoit,adesktophasthreecorecomponents(seeFigure10-2):
▼ T hecoreOSlayer,whichincludestheOSitselfandanypatchesitrequires.This coversthePASSmodelkernelwithouttheproductivitylayer.
■ T heapplicationlayer,whichisdesignedtoprovideaddedfunctionalitytothe enduser.Thisincludestheproductivityapplicationlayer,therole-basedlayer, andtheadhoclayerofapplicationscontainedwithinthePASSmodel.
▲ T heuserdatalayer,whichcontainsalloftheuser’sdata,includinguserproduceddocuments,presentations,andmore,aswellasapplication configurationsettingsanddesktoppersonalizations.
Thesearethethreekeycomponentsofadesktop,andifyoucanabstracttheselayers fromoneanother,youcansignificantlyreducedesktopmanagementoverhead.Thisis wheredesktopvirtualizationproductscanhelp.Becausethedesktopiscontainedwithin avirtualmachine,yougainalloftheadvantagesandfewoftheissuesthatcomewith machinemanagementwhenamachineistransformedfromthephysicaltothevirtual.
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Figure10-2. Theanatomyofadesktop
MOVETODESKTOPVIRTUALIZATION Moreandmoreorganizationsareturningtoavirtualdesktoptosimplifythedesktop managementmodel.Thereareseveralreasonswhydesktopvirtualizationoftenmakes moresensethanmanagingphysicaldesktops.
▼ F irst,youcanprovidecentrallymanageddesktopstousersonanyendpoint device—desktops,thinclients,Webclients,andmore.
■ S econd,youcanlockdownvirtualdesktopsbecausetheyarecontrolled centrallyand,therefore,areeasiertoprovision—justcreateonesingledesktop imageandcopyitasoftenasneeded.
■ Y ouspendlesstimeonendpoints—theactualphysicalPCs—becausetheyno longerneedtobemanagedastightly.Afterall,youonlyneedtheseendpoints toprovidearemotedesktopconnectiontothevirtualdesktop.
■ Y oucanprovideservicelevelagreements(SLAs)onlyforthecentraldesktop andnotfortheendpointitself.Userscanbeadministratorsontheendpoints, butlockeddownonthevirtualdesktop.Thisletsthemdowhattheywantto theendpoints,butremaincontrolledwithinthecorporatePC.
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■ Y oucanreducecostsandimproveservicestabilitybecauseyouknowwhere thestartingpointforeachPCis:fromyourgoldenvirtualdesktopimage.
■ Y oucancreatelockedandencryptedvirtualdesktopimagesthatcanbetimecontrolledtomeettimelyrequirements.Forexample,ifyouhaveastaffinflux tomeetaseasonalbusinessneed,youcangeneratetime-controlledPCimages forthedurationoftheeffort.
■ I nformationcanbesecuredbykeepingthevirtualdesktopinsidethe datacenter.Thiscangiveyoumorecontroloverintellectualproperty(IP); allyouhavetodoislockdowntheimageyoucreatesothatitdoesnothave accesstoexternaldevices.Itisconsiderablyeasiertomaintaincompliance whentheIPisstoredcentrallyanddoesnotleavethedatacenter.
▲ C omplexorsensitiveapplicationscanbeencapsulatedandisolatedinto specificPCVMstoensureproperoperation.Thisway,theapplicationdoesnot needtointeractorcoexistwithanyothers.
Inaddition,virtualdesktopinfrastructures(VDIs)cansupportthefollowing:
▼ N ewoperatingsystemmigrationscanbeeasiertoperformsinceresources areonlyrequiredcentrally,notlocally.Thereisconsiderablylessimpacton hardwarerefreshsinceendpointsonlyneedremotedesktopcapabilities.
■ Mergersandacquisitionsareeasiertomanagesincealldesktopsarecentralized.
■ Alternativeworkspacescanbeprovidedonanas-neededbasistoemployees.
■ Y oucanusecustomvirtualdesktopstoprovidecontractorswithsecured, encryptedmachinestoworkinyourenvironment.Thisway,theirown machinesneverneedtoconnecttoyournetwork.
▲ V irtualizedPCscanalsosupporttestinganddevelopmentenvironments,as seenearlierintheconstructionofthevirtuallaboratory(seeChapter6).
Butwhatisavirtualdesktop,andhowdoyoumakeitoperate? NOTE FormoreontheprosandconsofVDI,lookupVDIMakesSensebyRubenSpruijtatwww .virtuall.nl/articles/PublishedArticles/LanVisionVDIenglish.pdf.
AvailableDesktopVirtualizationProducts Thereareseveraldifferenttypesofdesktopvirtualizationengines.Theyusuallyfitwithin two different virtualization models: local versus centralized. The local desktop virtualizationmodel,oftencalledClient-sideDesktopVirtualization,focusesonusingthe endpoint’sownresourcesforrunningthevirtualdesktop.Virtualizationsoftwareisinstalledonthephysicaldesktop,andacorporatevirtualdesktopimageisprovidedtothe enduser.Theenduserthenrunsthevirtualdesktopontopoftheirphysicaldesktop.
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ThesecondmodeliscentralizedandisoftencalledServer-hostedDesktopVirtualization.Here,thevirtualdesktopwillrunontopofaproductionhypervisorandwillbe accessedremotelybytheenduser.Alltheenduserrequiresisanydevicethatsupportsa remotedesktopconnection.Thevirtualdesktopsrunontopofhostserversusingshared storagetoensuredesktopavailability. Inaddition,thelocalmodelsupportsbothmanagedandunmanagedproductusage. Managed product usage means that PC images are provided from a central authority andarecentrallycontrolled.Unmanagedmeansthattheusercancreateandruntheir ownversionsofvirtualdesktopimagesbecausethesoftwaretheyusesupportsthisability.Table10-1outlinesaselectionofthedifferentproductsprovidedbyvariousmanufacturersforbothlocalandcentralizedvirtualdesktops.Desktopvirtualizationisamarket thatisveryvibrantandmaywellincludeseveraladditionalofferingsbythetimeyou readthis.However,thevendorslistedinTable10-1havebeenonthemarketforsome timeandofferagoodvarietyofproducts. Asyoucansee,thereareseveraldifferenttypesofproductsandplatformsforthe controlofvirtualdesktops,bothlocallyandcentrally.
VirtualDesktopLicensing Whenworkingwithvirtualdesktops,aswhenworkingwithvirtualservers,youmust alwaysconsiderlicensingandmakesureeachuser’sdesktophasanappropriatelicense, whetheritisphysicalorvirtual.Ifyou’reworkingwithWindows,youwillgetabreak fromMicrosoftbecauseMicrosofthasreleasedtheWindowsVistaEnterpriseCentralizedDesktop(VECD)license.VECDprovidesuniquelicensestorunvirtualizeddesktops,bothlocallyandcentrally.Italsoincludesthefollowingfeatures:
▼ U nlimitedinstallsofWindowsVistaEnterpriseorofadowngradeddesktop OSonaserver.
■ Virtualdesktopsarelicensedbyaccessdevice,whateverthedevice.
■ E achusercanhaveuptofourvirtualinstancesrunningontheaccessdeviceat onetime.
■ Organizationscanruneitherstaticordynamicallyhosteddesktoparchitectures.
▲ VirtualdesktopscanrunonMicrosoftornon-Microsoftinfrastructures.
Asthenameimplies,thelicensereliesontheEnterpriseEditionofWindowsVista,which bydefaultrequiresanEnterpriseLicensingAgreementwithMicrosoft. NotethatobtaininganEnterpriseAgreementwithMicrosoftalsogivesyouaccessto Microsoft’sSoftwareAssuranceprogram,whichincludesseveralbenefitsfororganizations,notablytheMicrosoftDesktopOptimizationPack(MDOP)forSoftwareAssurance. MDOPincludesseveraltoolsthatarespecificallydesignedtosupportorganizationsrunningWindowsdesktops.ToolssuchasMicrosoftApplicationVirtualization,Microsoft EnterpriseDesktopVirtualization,AdvancedGroupPolicyManagement,AssetInventoryService,theDiagnosticsandRecoveryToolset,andDesktopErrorMonitoringareat thecoreoftheMDOPpackage.
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Manufacturer
Product
Managed
Unmanaged
VMware
VMwarePlayer
Providesafree engineforrunning VMsondesktops
VMware
VMware Workstation
Providesthemost advancedVMfeature setfromVMware
VMware
VMwareFusion
RunsVMsonMacs
VMware
VMwareAce
Providessecure, locked,andencrypted VMstorunonthe user’sdesktop
VMware
VirtualDesktop Infrastructure (VDI)
Centrallycontrolled desktopmanagement andprovisioning
Microsoft
VirtualPC
Microsoft
Kidaro
Providessecure, locked,andencrypted VMstorunonthe user’sdesktop
Citrix
XenDesktop
Centrallycontrolled desktopmanagement andprovisioning
InstallFree
InstallFree Desktop
Centrallycontrolled desktopmanagement andprovisioningwith offlinecapabilities
Desktone
Virtual-D Platform
Centrallycontrolled desktopmanagement andprovisioning
Quest Software/ Parallels
Bundled VirtualDesktop Infrastructure
Centrallycontrolled desktopmanagement andprovisioning
Providesafree engineforrunning VMsondesktops
Table10-1. DesktopVirtualizationTechnologiesandVendors
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Ifyouarerunningnon-Windowsdesktops,youmustworkwithyourmanufacturer toensureyouhaveappropriatelicensingforeachuserandeachinstanceofthedesktop. NOTE More information on VECD can be found at www.microsoft.com/virtualization/solutionproduct-vecd.mspx. More information on MDOP can be found at www.microsoft.com/windows/ products/windowsvista/enterprise/benefits/tools.mspx.
PotentialDesktopVirtualizationScenarios There are different scenarios for desktop virtualization, as outlined in the sample list of products included in Table 10-1. Some are focused on running the virtual desktop throughtheuser’sdesktop’scapabilities;othersarefocusedonrunningvirtualdesktops onservervirtualizationplatformsinacentraldatacenter.Infact,youcanrelyonvirtual desktopsinfourdifferentmodels. Thefirstmodelfocusesonlockedandencrypteddesktopvirtualmachines.Machines arecentrallypreparedandthenencryptedtoprotecttheircontent.Theyaredistributed toendusersonportabledevices,suchasUSBmemorysticks,DVDs,externalUSBdisk drives,orotherremovablestoragedevices.Becausetheyareencrypted,theyarecompletelyprotectedfromtampering.Theusermustprovidetheappropriateunlockingkey tolaunchtheVM.Becauseitrunsontheuser’sowndesktop,thismodelprovidesyou withtheabilitytocreateastandardlocked-downVMthatmeetsallcorporaterequirements (see Figure 10-3). Products that support this model include VMwareACE and Microsoft’s Kidaro—renamed to Microsoft Enterprise Desktop Virtualization—virtual desktops.ACErunsontopofVMwarePlayersincetheuseronlyneedstheabilityto execute the virtual machine, not create it. Kidaro relies on a locked-down version of MicrosoftVirtualPCtoexecutemachines.BoththePlayerandVirtualPCmustbepredeployedtotheuser’sdesktoportheusermusthavetheadministrativerightsrequired toruntheinstallationwhentheyreceivethevirtualmachine.
Figure10-3. Lockedandencrypteddesktopvirtualmachinesrelyondesktopcapabilitiestorun.
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Unmanaged desktop virtualization stems from the use of tools such as VMware WorkstationorMicrosoftVirtualPC.Bothtoolsareinstalledlocallyontheuser’sdesktop and rely on the desktop’s processing capabilities to run VMs. Users can also rely onothertools,suchasVMwareServerorMicrosoftVirtualServer,butthesetoolsalso requiretheinstallationofawebserver,whichconsumesevenmoreresourcesfromthe PC.Therefore,itisbesttousethedesktoptoolstomaximizethePC’sresourcesandrun asmanyVMsaspossible. This form of virtualization is called unmanaged, though it could be managed. In unmanagedmode,theuserinstallstheirownversionofthevirtualizationsoftwareand createsandrunshisorherownvirtualmachines(seeFigure10-4).Themostsignificant problemwiththismodelisthattheuserswhoperformtheseinstallationsareoftennot trainedtodoso.Thiscanleadtoroguevirtualmachinesthatmayruneitherunpatched andunprotectedor,worse,unsupportedoperatingsystemsthatcouldprovideanentry pointformalicioususers. Forexample,oneofourcustomershadauserwhoinstalledhisownvirtualization software and then installed an unpatched version of Linux within a virtual machine. WhatwasworsewasthatthemachinealsohadaseriesofopenTransmissionControl Protocol/InternetProtocol(TCP/IP)portsrunninge-mailservices,whichwerebroadcastontheInternet.Ofcourse,theorganization’sfirewallhadopenportsfortheirofficial e-mailservice,whichwasprotected,buttheLinuxmachine’se-mailservicewaswide open.Becauseofthis,itwastakenoverbyspammerswhouseditasane-mailrelay.So muche-mailwassentthroughthisserverthatanInternetserviceprovider’s(ISP)entire e-mail service was brought down. The organization only learned of the rogue Linux machinewhentheISPcontactedthemtofindoutjustwhatwasgoingon.Needlessto say,today,theorganization’sITpersonnelkeepacloseeyeonwhatgoesinandoutof theirfirewalls.Theyhavealsoinstigatedavirtualmachineprogramforendusers.They preparetheVMsandthenprovidethemasanITservicetotheuserswhorequirethem. Asyoucansee,itiseasytofaceVMsprawlwhenusersareallowedtoinstalltheir ownvirtualizationsoftwareandcreatetheirownvirtualmachines.ThisisanotherreasonwhyITshouldhaveaformalmachinecreationprogramforanyuserthatrequiresit.
Figure10-4. Unmanageddesktopvirtualizationcanleadtoissueswithintheorganization.
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Forexample,usingthevirtuallaboratoryoutlinedinChapter6wouldhelpreducethe chanceofVMsprawlinyourorganizationbecauseyouareprovidingVMsasanofficial ITservice. Thethirdmodel,statefulvirtualdesktops,focusesoncentrallymanageddesktops thataretiedtoeachspecificuser.Inthismodel,eachuserconnectstohisorherown particular desktop virtual machine(s). The VMs are stored in a central shared storage container,muchastheyarewhenyouvirtualizeserversoftware.Hostserversrunning productionhypervisorsmanageallofthedesktopvirtualmachinesandmakesurethey arehighlyavailable.Thismodeltendstorequireasignificantamountofstoragesince eachVMcaneasilytakeupdozensofmegabytesormore.UsersrelyonaremotedesktopconnectiontoconnecttotheirVMPCs(seeFigure10-5). Thelastmodel,statelessvirtualdesktops,focusesonthegenerationofvirtualmachines on an as-needed basis. Machines can either be generated when the user connectsortheycanbepre-generatedandlinkedtoauserwhenaconnectionrequestoccurs.Theadvantageofthismodelisthatthemachinesarecompletelyvolatileandbuilt onthefly.Thecoredesktopimageisgeneratedandthen,whentheuserisidentified duringtheconnection,theapplicationstheyrequireareappliedtothedesktopimage (seeFigure10-6).Theuser’sdataandpreferencesarealsoappliedatlogon.Whileyou maythinkthatthisprocessistime-consumingandcancauseuserdissatisfaction,itis notactuallythecase.Theidealvolatiledesktopwillalsorelyonapplicationvirtualizationtoprofileapplicationsonlywhentheuseractuallyrequeststhem.And,because everythingoccursonaback-endstorageareanetwork,applicationsanduserprofiles areprovidedthroughhigh-speeddisk-to-diskexchanges,whicharepracticallytransparenttousers,evenmultipleusers.
Figure10-5. StatefulvirtualdesktopsprovideadirectcorrelationbetweenauserandtheVMs theyrelyon.
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Figure10-6. Statelessvirtualdesktopsaregeneratedasneededwhenusersconnect.
Thislastmodelisusuallythemostpopular.Giventhatdesktopsarevolatileandtemporary,theyonlyrequirestoragespaceduringuse.Applicationsanduserdataarestored outsidethedesktopimage,andbecauseofthis,theorganizationhasnoneedtomaintain singleimagesforeachuser.Sinceeachdesktopisgeneratedfromasingleimage,you onlyhaveonesingletargettoupdatewhenpatchesareavailable.Thisgreatlysimplifies thevirtualdesktopmanagementmodel.
IdentifyDesktopVirtualizationAudiences Giventhevariousmodelsforvirtualdesktopusage,especiallythecentralized,volatile desktopmodel,itiseasytoseehowmovingtothismodelcouldbejustifiedwithinjust aboutanyorganization.Endpointsarenolongerthecoremachinesusersmustrelyon. Endpointsareonlyseenasdeviceswitharemotedesktopconnectionability.Becauseof this,younolongerneedtospendaninordinateamountofresourcesmanagingtheendpoint.Instead,youfocusonmanagingandlockingdownthevirtualdesktopimagethe usersactuallyrelyontoperformtheirwork.Buttoproperlymanagevirtualdesktops andgiveeachusertheverybestexperience,youmustbeabletocategorizeyouruser
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basesandassigntheappropriatesolutiontoeachtargetuseraudience.Therearethree audiencetypesyouwillneedtoworkwith:
▼ T hebasicproductivityworkerwillrequirefewerapplicationtypes.Normally, theywillrequirenothingmorethanthekernelofasystemconstructedonthe PASSmodelmentionedearlier.Theywillhaveintermittentusageandwillbe primarilytext-based.Theywillhavelimitedmouseusageandlimitedprinting requirements.Thisdesktopusertypewillloginatdistributedtimesandwill createavariableworkloadoncentralizedhostservers.Thisworkertypeis idealforthestandardvirtualizeddesktop.
■ T heknowledgeworkerwillrequireamorepowerfulcentralizeddesktop becausetheytendtorunmultiplebusinessandproductivityapplicationsat thesametime.Theyuseapplicationsthatarericheringraphicsandtherefore requiremorememoryperuser.Knowledgeworkersalsotendtobeloggedin atthesametime.IfyourPASSsystemkernelisproperlydesigned,itshould alsomeettherequirementsformostknowledgeworkers.Thismeansthatyou mustincludeatleastbasicgraphicstoolsalongwiththeproductivitysuites withinthekernel.Thevirtualdesktoptheyusewillrequirearichergraphical experienceandmoreresourcesperVM.
▲ T herichdesktopuserwillmostlikelyrunmultiplecomputer-andgraphicsintensiveapplicationsatthesametime.Engineersortradersareexamples ofthistypeofuser.Theyoftenrequirespecializedengineeringortrading peripheralsandwilloftenrequiremultipledisplaysconnectedatthesame time.Theywillalsorequirehigh-endgraphicsresolutions,something mosthostserverslack.Forthisreason,itisoftenbesttosolvetheseusers’ requirementswithbladePCs—PCsthatarecentrallyhostedindatacenters inbladeenclosures—insteadofvirtualdesktops,thoughvirtualdesktopsare improvingincapability.Forexample,MicrosoftacquiredCalistoTechnologies in2008.Calistospecializesinimprovingtheremotedesktopexperienceforend usersthrough3-Dacceleration.ThistechnologywillbeembeddedinWindows, whichshouldimprovetheremotedesktopconnectionusersexperiencewhen theyconnecttovirtualdesktops.Inaddition,VMwareisworkingwithTeradici andWysetoimproveremoteprotocolsupportinitsproducts.Inthesecases, thebladePCmaynolongerberequired.
As you can see, each user type requires a different centralized solution. However, as pointedoutearlier,centralizingthedesktopisnotalwaysthebestsolution.Table10-2 describesthedifferentsolutionsthatareavailableforreducingthecostofdistributed desktop computing. It lists several solutions, many of which have already been discussed, but it also includes technologies such as Presentation Virtualization, which is reallyserver-basedcomputing,andPCBlades.Italsooutlinestheimpacteachsolution hasontheend-userexperience. Relyonthistabletodeterminewhichsolutionbestfitsyourownusers.Categorize themwithinthethreecoreusertypesandthenidentifythesolutionyouneedtoapplyto
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Feature
FreeVM Engine
Advanced Centralized Encrypted LocalVM Presentation Virtual PC LocalVM Engine Virtualization Desktops Blades
Graphics
Fair
Fair
Fair
Fair
Good
Better
Video
Fair
Fair
Fair
Fair
Fair
Better
Performance
Average Average
Average
Average
Better
Best
Redundancy
Poor
Poor
Poor
Good
Best
Good
Printing
Good
Good
Good
Fair
Good
Good
USB
Fair
Fair
Better
Fair
Fair
Best
Active Directory Integration
Good
Good
Good
Good
Good
Good
Application Good Compatibility
Good
Best
Average
Best
Best
Management
Poor
Better
Poor
Average
Best
Best
Deployment
Poor
Good
Poor
Average
Best
Good
Table10-2. ComparingDistributedVersusCentralizedDesktopVirtualization
theirneeds.Todoso,youwillneedtoproperlyunderstandthevariousdesktopvirtualizationtechnologiesanddeterminewhichwillbestfittheneedsofbothyourorganizationandyouruserbase.
CENTRALIZEDDESKTOPVIRTUALIZATION INFRASTRUCTURES When you run a desktop virtualization infrastructure (VDI), you need to determine which of the three supported models will best fit your organization’s requirements. Thesethreemodelsinclude:
▼ Persistentorassigneddesktops Thedesktopistiedtoonesingleuser andthesamedesktopisprovidedtotheusereachtimeheorshelogson. Asmentionedearlier,thismodelrequiresconsiderablecentralstoragespace. Usethismodelifyouhaveonlyafewusersorifstoragespaceisnotaconcern inyourorganization.
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■ N onpersistent,volatile,orpooleddesktops Anew,genericdesktop isprovidedtotheusereachtimeheorshelogsontotheinfrastructure. Applicationsanduserprofiledataareprovidedatlogontocustomizethe sharedimagetomeetthisuser’sparticularrequirements.Thismodelrequires considerablylessstoragebecauseeachuser’senvironmentisgeneratedfrom onecentralimage.Allofthecontentthatisspecifictoaparticularuseris storedinadifferencingfile.Adatabasecontainingtheuser’sspecificsettings isusedtocustomizetheimageandgeneratecustomcontent,suchassecurity identifiers(SID)forthemachine,machinename,andotherdatathatmustbe uniqueinanActiveDirectoryenvironment.
▲ Persistentclonedesktop Apersonalizablecloneisgeneratedthefirsttime auserlogson;fromthatpointon,theuserreliesonthatcloneeachtimeheor shelogsbackon.Thismodelonlyrequiresstorageoncetheuserhasloggedon togeneratethecustomdesktopimage.
Eachmodelhasitsownbenefitsandeachhasitsowndrawbacks,butthevolatiledesktoptendstobethemostpopularbecauseofitsminimalstoragerequirementsandits reduced update management overhead. However, the key to centralized desktop virtualizationisthenotionofadesktopbrokerorasoftwarecomponentthatmatchesthe usertoaparticularvirtualmachine—volatileorpersistent—atlogon.Thebrokermakes itpossiblefortheITadministratortodynamicallyassigncustomsettingstoeachuser. Withoutthisbroker,ITadministratorseitherneedtomanagethisassignmentmanually orhaveusersconnecttospecificmachinenamesorIPaddresses.Withoutthisbroker, therecanbenoconceptofvolatilevirtualdesktops. Severalvendorsprovidesolutionsforcentralizeddesktopvirtualization,orVDIasit iscommonlycalled.Thethreemainprovidersonthemarketforcentraldesktopvirtualizationarethesameasthoseforservervirtualization.TheyincludeVMware,Microsoft, andCitrix.VMwarewasthefirstorganizationtoprovideaVDIsolution—orrather,their customerswerewhentheystartedusingVMware’sservervirtualizationtechnologiesto hostdesktops.Afterseeingthepotentialmarketforcentralizingdesktops,VMwarecreatedtheVDIsolutionbybasicallylinkingitsservervirtualizationenginewithacustom desktopbroker. CitrixalsocreatedaVDIsolution,theXenDesktop,bylinkingallofitsvirtualizationsolutionstogether.XenDesktopreliesontheXenServervirtualizationengineaswell as Citrix’s presentation and application virtualization solution: XenApp. It also uses Citrix’sIndependentComputingArchitecture(ICA)clienttoimprovetheenduser’sremote desktop experience. In addition, XenDesktop can work with both VMware and Microsofthypervisorswhichmakesitagoodchoicenomatterwhichhypervisoryou run.Forexample,Microsoftdoesnothaveitsowndesktopbroker.Therefore,itrelieson theCitrixXenDesktopsolution,butthistime,usingtheWindowsServer2008Hyper-V virtualizationengineastheback-end. As mentioned earlier, there are also other companies that offer desktop brokers and thereforedesktopvirtualizationsolutions.TheseincludeInstallFree,Quest,andDesktone. Eachsolutionhasitsownstrengths.Youmustselectcarefullybeforeyouimplement avirtualdesktopsolution.
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VMwareVirtualDesktopManager MostorganizationsrunWindowsastheirdesktopinfrastructure.Thisischanging,but becauseofthis,mostVDIsolutionsaredesignedtolinktoandintegratewithWindows technologies.ThisisthecasewithVMware’sVirtualDesktopManager(VDM).VMware VDM,whichisalsocalledVMwareView,isasolutionthatprovidesvirtualdesktopprovisioningonaone-to-onebasiswithusers.Itcreatesonevirtualmachineimageperuser. TheseVMscaneitherbepersistentorvolatile.Atthetimeofwriting,VDMwasthemost popularcentralizedvirtualdesktopsolution,withover20,000customersworldwiderelyingonit.AccordingtoVMware,thesecustomersincluded100percentoftheFortune 100companies. VDMincludesthefollowingfeaturesandcomponents:
▼ T hevirtualizationback-endisprovidedbyVMware’sVirtualInfrastructure (VI)withESXServerorESXi.Ifhighavailabilityisrequiredforthevirtual desktops,VirtualInfrastructureisrequiredtoprovidebothscalabilityandhigh availability.Italsoprovidespolicy-basedresourcemanagement,lettingthe systemmovevirtualmachinesasneededtoappropriatehoststoprovidethem withrequiredresources.
■ B ack-endmanagementisperformedthroughVirtualCenter,whichisthesame aswhenyourunservervirtualization.
■ V DMprovidesdirectintegrationwithMicrosoft’sActiveDirectory(AD)for accountprovisioning.NotethatADintegrationisnotoptional.Inordertorun VDI,youmusthaveanexistingADdesignedwithaproperstructure.Note thatnoschemachangesarerequiredtointegrateVDIwithyourAD.
■ V DMcanrelyonexistinguseraccountsandpoliciestoassigndesktopVMs tousers.Iftwo-factorauthenticationisrequired,youcanintegrateVDMwith RSASecurID.LinkingVDMwithADprovidesasingle-sign-onsolution,which makesVDMaccessbyendusersmuchsimpler.TheyjustlaunchtheVDM clientandlogintoADtogainaccesstotheirownparticularVM.
■ V Mware’sdesktopbrokeristheVirtualDesktopManager,whichprovides desktopprovisioningtoendusers.Oneofitsmostpowerfulfeaturesisits abilitytoactasabrokertorelinkuserstoexistingvirtualdesktopseach timetheuserreconnects.ManagementoftheVDMisperformedthrough awebinterface.Usingthisinterface,administratorscanassignanddeploy desktopsfromonecentrallocation.Theycanalsocontrollogoffpoliciesand provisioningrules.
■ V DMoffersanoptiontodeployvirtualdesktopVMswithinperimeter networks,lettingremoteandtravellingusersaccesstheirdesktopVM.
■ V DMreliesonavarietyofcommonendpointstoconnecttotheirVDMVM. TheseendpointsincludecomputersrunningWindowsoperatingsystems— notethataspecialclientisrequired;thinclientdevices;orbrowsersrunningon eitherWindows,Linux,orMacintoshoperatingsystems.
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■ P ersistentdesktopsinVDMaregeneratedfromacommontemplate.Users mustbemanuallyassociatedwithavirtualdesktopbyanadministrator throughtheVDMinterface.Thisway,eachusergetsadedicateddesktop. Usersareconnectedtothesamedesktoponeachsubsequentconnection.
▲ V olatiledesktopsinVDMarealsogeneratedfromacommontemplate; however,individualisolateddesktopsarereturnedtothedesktopVMpool aftereachusebecauseeachdesktoprevertstoitspredeterminedstatefor futureuseatlogoff.Ifyouwanttoretainusersettings,youmuststorethem outsideofthedesktopVMimage.
As you can see, the overall VDM solution is made up of several moving parts (seeFigure10-7),butitcanprovideapowerfulinfrastructureforcentralizedvirtual desktops.
Figure10-7. VMware’sVirtualDesktopManager
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Contents
VMwareVDM StarterKit
VMwareInfrastructure3 Enterprise EditionforVDM VMwareVirtualCenter
X
VMwareVDM Bundle
VMware VirtualDesktop Manager
X
X X VirtualCenter VirtualCenter Foundation Management (limitedtothree Server hosts)
VMwareVirtualDesktop Manager2
X
X
X
Licensesforconcurrent 10 desktopvirtualmachines (onestarterkit percustomer)
100 100 (add-onpacks (add-onpacks oftenavailable) oftenavailable)
SupportRequirements
Supportand Subscription (SnS) requiredand soldseparately
Supportand Subscription (SnS) requiredand soldseparately
Supportand Subscription (SnS) requiredand soldseparately
Table10-3. VMwareVDMEditionsandFeatures
Table10-3outlinesthevariouseditionsofVDIVMwaremakesavailable.Ifyouopt torelyonVDMforcentralizeddesktopvirtualization,choosetheeditionthatbestfits yourneeds.Notethatyoucanuseastarterkit,obtainanentirebundle,orsimplyadd Virtual Desktop Manager to an existing Virtual Infrastructure.Also note that because ESXServersupportsboth32-bitand64-bitmachines,VDMwillletyouruneitherx86or x64versionsofyourfavoritedesktop. NOTE FormoreinformationonVMwareVDM,gotowww.vmware.com/products/vdi.
RunVDMwithEMCCelerra As mentioned earlier, running a virtual desktop infrastructure requires a centralized sharedstoragesolution.Bydefault,whenyourunVDMwithsharedstorage,itgeneratesoneVMperuser,eatingupconsiderablespace.However,EMC,VMware’sparent
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company,offersaspecialstorageenginecalledCelerrathatoffersspecialfeatures,which include,amongotherthings,theabilitytovastlyreducetheamountofstoragerequired byvirtualdesktopimages.UsingtheCelerraSnapSurefeatureallowsyoutogenerate copiesofthevirtualdesktopimagesbyusingdifferentialfilesthatstemfromtheoriginal diskimage.Eachdifferentialfilethentakesupafractionofthespacerequiredfornormalimages.Thisstoragemethodisconsiderablymoreefficientthantraditionalstorage methods. SinceyouhavetousesharedstoragetorunVDMbecauseitrequiresVMware’sVirtualInfrastructure,andsharedstorageisarequirementtorunVI,youshouldseriously considerusingatechnologysuchasEMC’sCelerraasthestoragecontainer,oratleast useastoragecontainerthatincludesfeaturessimilartotheSnapSurefeature.Otherwise, youwillendupstoringmultigigabytefilesforeachvirtualdesktopimage.SnapSurecan saveconsiderablecostsindiskspaceand,therefore,diskdrives,yetprovideyouwithall ofthefunctionalityrequiredtomakeVDMoperatecorrectly. NOTE Remember that by using NetApp storage, you automatically gain access to this feature sinceNetApphastheabilitytodeduplicatelivestoragecontents.Becauseofthis,NetAppstorage containersreducestoragecostsbyupto40percentwhenstoringvirtualmachinesusingthesame operatingsystem.
VMwareView InSeptember2008,VMwareannouncedanewvisionforcentralizeddesktopvirtualization,basicallytransformingthetraditionalVDMofferingintoonethatletuserslinkto asinglecentralVMwherevertheyare,eveniftheymaybeoffline.VMwareViewisa portfoliooftoolsthatworktogethertogiveusersasingleviewofalltheirapplications anddatainastandarddesktopthatcanbeaccessedfromanydeviceorlocationandcan evenbecarriedaroundoffline. VMware was well positioned to make this a reality in the following months since theywerethefirsttodeliveraVDI.VMwaredevelopedtheVirtualDesktopManager (VDM)toletadministratorscreatedesktopvirtualmachines(DVMs)andassignthem tousersthroughActiveDirectory.Despitethefactthattheywerefirsttomarketwith VDI,VMware’sproductlaggedbehindothersinsomekeyareas.Forexample,Citrix’s XenDesktophastheabilitytocreatedesktopvirtualmachinesfromonesingleread-only coreVM.AllothermachinesaremanagedasdifferentialfilestiedtothisVM.Whenyou considerthateachDesktopVirtualMachine(DVM)caneasilybeaslargeas10GBinsize, youquicklyrealizethebenefitsXenDesktophasoverVDM,whereeachmachinetakesup itsownspace.Becauseofthisfeature,XenDesktopcaneasilysaveupwardsof50percent ormoreofalldiskspacerequiredtohostDVMs—andthat’snottheonlyfeatureithas overVDM.HoweverVMware’sdesktop-anywherevisiongoesbeyonddifferentialfiles foreachDVM.ItalsoincludestheabilitytoruntheDVMoffline,somethingthatfew,if any,productsoffertoday.Currently,centralizeddesktopvirtualizationisplaguedwith thesamefailingsasserver-basedcomputingsuchasTerminalServices:Youhavetobe connectedtoaccesstheservice.Todothis,VMwarehasbroughttobearitsconsiderable lineupofdesktopvirtualizationtoolsandlinkedthemwithVDMtocreateoneseamless
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DVMexperienceforusers.VMwareViewallowsuserstorelyonanydevice—standard desktoporlaptoprunningWindowsortheMacintoshOS,Webbrowser,publiccomputer, thincomputingdevice,orevenamobilephonesuchastheiPhone—toaccesstheirDVM. In addition, users are able to carry their DVM on transportable devices, such as USB memorysticks,orrunthemofflineontheirlaptops.Betteryet,usersareabletomake offlinemodificationswithintheirDVMandhavethemautomaticallysynchronizedwith theircentralizedDVMoncetheyreconnect. VMwarehasbeenmaintainingafulllineofdesktopvirtualizationproducts,andbecause ofthishadtheabilitytoturndreamintorealityinarelativelyshorttime.ForVMwareView toworkasadvertised,VMwarehadtocomeupwithseveraldifferentinnovationsandlink themwiththeirexistingdesktopvirtualizationproducts(seeFigure10-8).
Figure10-8. VMwareViewallowsuserstoaccesstheirDVMsfromanywhereandevenuse themoffline.ItemsnotinboldarenowpartoftheVMwareViewarsenal.
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First, VMware needed the tools to support DVM access from anywhere; however, it already had several of them. VMware’s Virtual Desktop Infrastructure includes the VirtualDesktopManager,whichistheDVMbrokerandassignsaDVMtoeachuser. VMwareWorkstationisVMware’sflagshipdesktopvirtualizationengineandthrough its Unity feature can expose applications contained within desktop virtual machines withoutexposingthevirtualdesktopitself.Thisprovidesaseamlessinteractiontousers andmakesitmucheasierforthemtoworkwithvirtualmachines.However,VMware reliedonVMwarePlayer,afreevirtualmachine-executionengine,torunofflineDVMs onWindowsdesktops,throughwebbrowsers,oronWindowslaptops.VMwareACE alreadyletsuserscarrytheirDVMsonUSBsticks.VMwareFusionletsyourunDVMs ontheMacintoshOS.SoVMwarewasgoodtogoatthislevel. Second,VMwareneededtoimproveDVMgraphicsonendpointdevices.Forthis, VMwarehasannouncedthatitwillbeworkingwithmanufacturerTeradicitofurther developTeradici’sPC-over-IPprotocoltoreplacethedefaultRemoteDesktopProtocol (RDP)builtintoWindowsandimprovegraphicscontrol.Onceagain,Citrixisoneupon VMware here with its Independent ComputingArchitecture (ICA), a remote protocol thathasvastimprovementsoverMicrosoft’sRDP.Microsoftisalsoworkingtoimprove graphicsperformanceinRDP. Despite this, VMware is now well positioned to regain mastery over VDI through VMwareViewthroughtheadditionofseveralcomponents.
▼ T heabilitytorunaDVMonapersonaldigitalassistant(PDA),suchasthe iPhoneorevenWindowsMobiledevices.Thiswillrequireanewvirtual machineplayerorVMware’splannedcustomremotedesktopprotocol.
■ T heintegrationofabetterremotedesktopprotocol,whichwillhavetobe installedasacoreutilitywithindesktopsandremotedevices.VMware hasannouncedthatitisworkingwithTeradicitointegrateitsPC-over-IP protocoltomeetthisneed,butthatisnotitsonlyimprovementatthislevel. VMwareisalsoworkingwithWyseTechnology—makersofthinclients—to licenseWyse’sTCX-MMRsoftwareforimprovedremotemultimedia experienceandtoincreasemultidisplaysupport.Bothsoftwareproductsrun ontheendpointdeviceand,therefore,havenoimpactonback-endserver performancewhileimprovingtheend-userexperience.Thesesoftware productswillbeavailableforboththinclientsandfull-fledgedPCs.Overall, VMwarewillprovidemultiprotocolsupport,lettinguserschooseamong thedefaultMicrosoftRDP,Teradici’sPC-over-IP,theWyseproducts,oreven otherprotocolsfromHPandSun.
■ T heabilitytorunofflinedesktopsallowsuserstocheckoutavirtualdesktop fromthecentraldatacenterstoreandrunitofflinetofinallycheckitbackin whentheyreconnecttothedatacenter.
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■ T hecapabilitytostreamDVMstoofflinecontainerssuchaslaptops.Also, theabilitytostreamvirtualapplicationsintovolatiledesktops.Streaming desktopsandapplicationsislikestreamingvideos:Youonlyneedacore amountofinformation—sometimeslessthan10percent—tobeabletobegin usingthetool,savingbandwidthandsupportingtheapplication-on-demand concept.VMwarenowhasOfflineDesktoptodothis.Symantec,who alsooffersapplicationvirtualizationthroughitsSoftwareVirtualization Solution(SVS)Professionaloffering,hasoneofthebeststreamingengines onthemarketthroughitsacquisitionofAppStream.AppStreamcanstream desktopsaswellasapplications,butSymantecisnotusingthiscomponentin itsofferingasyet.
■ T heabilitytocreatedifferentialDVMsfromonecentralread-onlyDVMimage andprovisionthemasneededbasedonuserdemand.Rightnow,XenDesktop canprepopulatevolatileDVMsinanticipationofuserdemand.Forexample, ifyouhave500userslogginginbetween8and9a.m.,XenDesktopcanensure thatalloftherequiredDVMsarecreatedbeforehandtoincreasesystem responsetouserdemands.VMwarehasthebrokerwithVDM,andnowuses VMwareComposerasadifferentialengineandprovisioningtool.
▲ T heabilitytovirtualizeuserprofilestosupportvolatiledesktopsandcapture userchanges.However,thiscanbedonewithbasicWindowstechnologies, suchastheroamingprofileandfolderredirection,sotheneedforathird-party toolisnotpressing.Microsoftwasthefirsttoinventprofilevirtualization byembeddingthiscapabilityinWindows,acapabilitythatprovidesoffline supportthroughdatacachinginthelocaldevice.Withdesktopvirtualization, profilevirtualizationtakesonnewmeaningandbecomesacorepartofany VDIsolution.
VMwareshippedViewwithinthreemonthsofmakingitsinitialannouncementofthe product.HavinghundredsoreventhousandsofDVMsrunningfromonesinglecore image;havingonlyonesingleimagetoupdateandmodifywhenneeded;lettingyouaccessthisimagefromanywhereatanytime;capturingandprotectingallofyourchanges, onlineandoffline;andbasicallytyingtheusertoonesingledesktopimageistheright directionforcentralizeddesktopvirtualization.Viewisavailableintwoversions.EnterpriseeditionprovidesfunctionalitysimilartoVDM.ThePremiereditionincludesallof thetoolsthatarerequiredinatrueDVMsolution. NOTE ToviewavideoofVDMinaction,gotohttp://blogs.vmware.com/vmtn/2008/02/bring-on-thevd.html.
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CitrixXenDesktop Asmentionedearlier,Citrixalsooffersacentralizeddesktopvirtualizationsolution,the XenDesktop.CitrixXenDesktopisasolutionthatprovidesvirtualdesktopprovisioning onanas-neededbasistousers.Bydefault,itreliesononesinglebaseimage,verymuchlike thecombinationofVMwareVDIwiththeEMCCelerrastorageareanetworkorVMware View.All desktops are provisioned from a single image through software and will run fromthecoreimage,regardlessofthesharedstoragecontaineryouuse.Thiscoreimageis notduplicatedatanytime.Thisfeaturealonecansaveupto40percentofstoragespace,a considerablesavings,whichoftenoffsetstheoriginalcostofaXenDesktopsolution. XenDesktopwasformedbycombiningthefeaturesoftheXenServerservervirtualizationenginewiththoseofCitrix’sXenAppdeliverymechanism,aswellasthefeaturesetfromanacquisition,thatofArdence.Ardenceprovidesthetechnologyrequired togeneratedifferentialfilesfromthecoredesktopimage.Thistechnologynowallows XenDesktoptorelyonadatabasetoautomaticallyredirectregistryqueriesforcritical PCitems,suchascomputername,ActiveDirectorydomainrelativeID(RID),andsoon. ThismethodletsXenDesktopmanagehundredsoreventhousandsofdifferentialimagesbasedononesinglecoreimage. This is a critical feature because normally, you need to customize each PC image through the System Preparation Tool (SysPrep.exe). SysPrep will automatically depersonalizeaWindowsPCimagesothatitmaybereproducedasmanytimesas required.WhenthePCimageisopened,theSysPrepprocessautomaticallyrepersonalizestheimage,givingittherightSID,RID,computername,andsoon.Whenyou usetheXenDesktop,youdonotneedtoperformthistask;however,youdoneedto create a reference computer image and prepare it according to your organizational standards.Then,insteadofdepersonalizingtheimagethroughSysPreptogeneratea sourceimage,youcreateasecond,read-onlycopyofyourgoldenimage.Thissecond copythenbecomesthecoreimageusedbyXenDesktop.Itismaintainedinread-only mode.Userchangesandcustomizationsarecapturedinthedifferentialfileandeither discarded when the user logs off (stateless PC image), or saved to a personal user file (stateful PC image). Differential files are block-level files that capture only the changesmadetothecoreimage. This is one of the most impressive features of the XenDesktop. However, because XenDesktopisfromCitrixandCitrixhasyearsofexperienceinremoteWindowscomputing,XenDesktopalsoprovidesimprovementsintermsofremotedesktopdelivery because it relies on Citrix’s ICA protocol instead of Microsoft’s RDP. ICA provides a considerableimprovement,especiallyintermsofgraphicsrendering,overRDP,which makestheend-userexperiencericherandmorelifelike.Thissetoftechnologiesiscalled SpeedScreeninXenDesktop. NOTE ToviewthedifferencebetweentheRDPandtheICAexperience,seethedemonstrationon YouTubeatwww.youtube.com/watch?v=_RMTM7vaMnI.
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Traditionally, XenDesktop will require a XenServer back-end, the XenDesktop— whichactsasthedesktopdeliverycontrollerorthedesktopimageprovisioningengine— andtheXenAppdeliveryservertoprovideremotedesktopconnectivitytothedesktop imagesthroughtheICAprotocol(seeFigure10-9).However,becauseXenDesktopwas formedpartlyfromtheArdenceacquisitionandArdencesupportedVMwareESXServer first,italsosupportsafullVMwareback-end.Inaddition,becauseofitsstrongpartnershipwithMicrosoft,XenDesktophasbeenadaptedtosupportaWindowsServer2008 Hyper-Vback-end.ThismeansthatyoucanusetheXenDesktopsolutionwithanyofthe majorservervirtualizationengines.Thisisaboonformosteveryorganizationbecause earlyadoptersofservervirtualizationwillalreadyhavebothCitrixPresentationServer (nownamedXenApp)andtechnologieslikeVMwareESXServerorMicrosoftVirtual Serveralreadyinplace.Sincetheyalreadyhaveaservervirtualizationinfrastructureand theyalreadyownCitrixproducts,addingXenDesktopisoftenalow-costsolution. XenDesktopcomesinseveraleditions,eachincludingitsownfeatureset.Table10-4 outlineseachoftheseeditionsandthefeaturesetitincludes.Asyoucansee,becauseCitrix has a lot of experience in presentation virtualization (PresentV), many of its PresentV featuresareincludedineacheditionofXenDesktop.OneeditionevenincludesCitrix EasyCall—afeaturethatintegratestelephonecommunicationswithanyapplication,and stemsfromtheoriginalPresentationServerbeforeCitrix’sacquisitionofXenSourceand Ardence. XenDesktops can either be persistent or pooled. Persistent desktops retain the differentialinformationgeneratedbyeachuser.Theuseristhenconnectedtothisparticular differentialfileeachtimeheorshereconnects.Pooledimagesarestatelessimagesthat areresettoastandardstateeachtimeauserlogsoff.Obviously,pooledimagestakeup lessstoragespace.Eachimagemode,persistentversuspooled,appliestoadifferentuser type.Persistentimageswouldmostlikelyapplytopermanentusers,whilepooledimages are best for temporary or task-based employees who do not need to retain customizationsandpreferences.Pooledorpersistentimagescaneitherbex86orx64versionsofthe desktopOSsinceallofthesupportedvirtualizationengines—VMwareESXServer,Citrix XenServer,orMicrosoftHyper-V—supportboth32-bitand64-bitVMs.
Figure10-9. ThecomponentsoftheCitrixXenDesktopsolution
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Advanced Enterprise Platinum
BladePCSupport
X
X
X
X
X
BroadHypervisor Support
X
X
X
X
X
Citrix-ReadyProducts
X
X
X
X
X
DesktopAppliance
X
X
X
X
X
DesktopAssignment
X
X
X
X
X
HeterogeneousClient Support
X
X
X
X
X
InstantOn
X
X
X
X
X
SessionManagement
X
X
X
X
X
SessionReliability
X
X
X
X
X
SpeedScreen
X
X
X
X
X
UniversalPrinterDriver
X
X
X
X
X
VirtualMachine Infrastructure
X
X
X
X
X
HighAvailability/ Failover
X
X
X
X
SecureRemoteAccess
X
X
X
X
DesktopImage Management
X
X
X
DesktopStorage Optimization
X
X
X
On-DemandDesktop
X
X
X
On-DemandImage Provisioning
X
X
X
X
X
IntegratedAppDelivery DesktopPerformance Monitoring
X
DesktopSupport
X
EasyCall
X
WideAreaNetwork Optimization
X
Table10-4. CitrixXenDesktopEditionsandFeatureSets
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Sinceeachimageisbasedonacentralcoredesktopandisgeneratedatlogon,you mightthinkthatittakessometimefortheimagetobuildwhenauserfirsttriestoactivateitbyloggingon.Itwillindeedtakesometime,especiallyifthousandsofuserslog onatthesametime,eventhoughthedifferentialfileisasmallfile.However,Citrixsolves thisproblemthroughimagepre-provisioning.XenDesktopallowsadministratorstoset imagegenerationpoliciesthatwillpre-populateimagesbeforeusersbegintologon.For example,takethefollowingscenario.OrganizationAhasthreemainoffices.OfficeAis inNewYorkCityandcontains500users.OfficeBisinSaltLakeCityandcontains200 users.OfficeCisinSanFranciscoandcontains400users.Eachmorning,theuserslogon between7:00and9:00a.m.;however,becauseeachofficeisinadifferenttimezone,the loadontheback-endhostserversissomewhatattenuated. Byusingpre-populationpolicies,theadministratorsatOrganizationAhaveXenDesktopgenerateimagesaheadoftimebeforeusersbegintologon.Thepolicygenerates500 machinesinNewYorkCityat6:30a.m.Easterntime,200machinesat6:30a.m.Mountain time(twohourslater),and400machinesat6:30a.m.PacificTime(onehourlater).While thisscenarioisabitunrealisticbecausenoonestartsworkat7:00a.m.ontheWestCoast, itdoesillustratethepowerofpre-provisioningwithXenDesktoppolicies.Andthrough XenDesktop’swideareanetwork(WAN)accelerationfeatures,allofthedesktopscanresideintheNYCdatacenterandyetalluserscanhavearichvirtualdesktopexperience. NOTE For more information on the XenDesktop, go to www.citrix.com/english/ps2/products/ product.asp?contentID=163057.ForavideocomparingVMwareVDIwithCitrixXenDesktop,goto www.youtube.com/watch?v=J_i_EpZHMLc&feature=related.
OtherTechnologies Asmentionedearlier,CitrixandVMwarearenottheonlyprovidersofcentralizeddesktop virtualization products. InstallFree, Quest, and Desktone also offer similar products.Ofthethree,onlyInstallFreeoffersatechnologythatmanagesitsownPCimages. QuestandDesktoneofferproductsthatarereallyonlyfront-endstoothervirtualization technologies.
TheInstallFreeDesktop InstallFree uses a custom engine that generates a mini-desktop which runs based on the resources of the local machine. This technology relies on InstallFree’s application virtualizationengine,butinsteadofgeneratingapplicationsthataredecoupledfromthe operatingsystem,theseapplicationsareencapsulatedinsidethemini-desktopandrun asiftheywerearealdesktop.InstallFreeVirtual(IFV)desktopsarecontrolledcentrally throughActive Directory, but because they are processed locally, relying on the PC’s ownresources,theyareavailablebothonlineandoffline.Andbecausetheyarebased ontheIFVapplicationvirtualizationengine,theyarenotrealvirtualmachinesanddo notrequireavirtualizationengineontheback-end.Machinescanruneitherx86orx64 versionsofWindows;however,inordertorunanx64version,theoperatingsystemon thehostorphysicaldesktopmustbeanx64OS.
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TheInstallFreeapplicationvirtualizationengineisanexecutablethatcanbeloaded onanysystem,whetherornotyouhaveadministrativerights,becauseitrunsinuser modeonthehostOS,notkernelmode.Thismeansyoucancarryavirtualdesktopona portableUSBmemorystickandplugitintoalmostanyPC,evenalocked-downpublic PC. This gives you a lot of flexibility, both inside and outside the organization. Even thoughtheyarenotbasedonatraditionalvirtualizationengine,IFVdesktopimagesappearandoperateastraditionalPCimages.Theycanbelocalized,personalized,andeven encryptedforcontentprotection. Userdataisstoredinanencryptedfilethatisexternaltothedesktopsothatitcanbe protectedatalltimes.ApplicationsmustbevirtualizedusingtheIFVengineandmust bepreparedinadvance.InstallFreeDesktopistheonlysolutionthatcurrentlyprovides offlinesupportforvirtualdesktops,butitspreparationrequiresthefulluseoftheInstallFreesolution.Moreonthistopicwillbediscussedinthefollowingchapteraswediscuss thevirtualizationofapplications.However,ifyouneedbothonlineandofflineaccessto virtualdesktops,perhapsInstallFreeisthesolutionthatbestmeetsyourneeds. NOTE For more information on the InstallFree Desktop, go to www.installfree.com/pageload .aspx?page=products_InstallFree_Desktop.html.
TheDesktoneDesktopAsAService Desktoneisuniqueinthattheyoffervirtualdesktopprovisioningforbothenterprise andserviceproviders,hencethenameDesktopAsAService(DAAS).Enterpriseprovidersmanagetheirowninternalvirtualdesktops,butdonotneedtohaveaccesstoafull datacenterinfrastructurebecausetheentireservervirtualizationinfrastructureismanagedoffsiteinadatacenterownedandmanagedbyadesktopserviceprovider(DSP) runningDAAS.Thisgivesorganizationsofallsizesaccesstovirtualdesktopsandcan allow them to reduce their costs since they do not need to own the bits that support desktopvirtualization. DAASreliesontwokeycomponents:theVirtual-DPlatformandtheDesktoneAccessFabric.TheAccessFabricisthedesktopbrokerthatconnectsuserswiththeirown particulardesktop.Itisdesignedtodelivera“best-fit”desktoptoeachuserbasedon policies, user entitlements, access point, and the available resources in the datacenter. ThisinfrastructurelinkstoyourownexistingActiveDirectoryandgivesyoufullcontrol overthedistributionandallocationofthedesktops. Theback-endiscompletelyremovedfromyourowndatacenterandishostedinthe DSP’scenter.Thismakesiteasiertodeployandrunvirtualdesktopinfrastructuresbecauseyoudonotneedtoimplementtheservervirtualizationcomponents—hostservers, sharedstorage,andmore—thatarerequiredtohostthevirtualdesktopimages.Thisisa novelapproachandmaywellfityourneedsifyoudonotwanttoandhavenotimplementedservervirtualizationalready. AccordingtoDesktone,theirsolutionissimplertoimplementbecauseyoudonot needtoworryabouttheback-endhostenvironment.Youdon’tevenneedtoknowon whichvirtualizationengineitisrunning.AllyouneedtodoishookupwithaDSPand begintovirtualizeyourdesktops.Atthetimeofthiswriting,DesktonehadtwoDSP partners:IBMandHP.Morewillsurelycomeintime.
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IfyouwanttorunVDIbutdon’twantthehassleofimplementingthehostserver infrastructure,Desktonemaywellbethebestsolutionforyou. NOTE FormoreinformationontheDesktoneDAAS,gotowww.desktone.com.
TheQuestProvisionNetworksVirtualAccessSuite Quest Software also offers a VDI tool through the acquisition of Provision Networks. ThenewQuestVirtualAccessSuite(VAS)isadesktopbrokerthatoffersaVDIthatis independentoftheback-endservervirtualizationengineyourun.Atthetimeofwriting,VASsupportedVMware,Citrix,Microsoft,VirtualIron,andParallelsvirtualization engines,lettingyouuseanyoftheenginesyoumayalreadyhaveinplace.VASiscomposedoffourcoreproductsandfeatures.
▼ T heVirtualAccessBroker,whichlinksuserswithvirtualdesktopsthrough linkswithyourinternalActiveDirectory.
■ T heAccessInfrastructure,whichistheconduitthatallowsendpointssuchas desktopPCsorthinclientstolinkwiththevirtualdesktopsthroughaweb interface.
■ E nhancedEnd-UserExperienceandLast-Milefeatures,whicharedesignedto providerichgraphicalexperiencesforusersofthevirtualdesktops.
▲ E nd-PointComputing,whichisthecomponentthatlinkstheend-user’s requirementswithapplicationsanddatathroughthewebinterface.
EachofthesetoolsmakesupQuest’sVASandprovidesacompleteVDIimplementationsolution.Ofcourse,youmusthaveyourownservervirtualizationinfrastructure inplace.IfyouneedanindependentVDIsolution,perhapsQuestVASisthesolution foryou. NOTE FormoreinformationontheQuestVAS,gotowww.provisionnetworks.com/solutions/vas/ vas.aspx.
PROFITFROMVDI As you can see, virtual desktop infrastructures offer much in the way of simplifying desktopmanagementandreducingthevariousissuesyoufacewhenworkingwithdistributeddesktops.Desktopsaredeliveredquicklyandreliablytoanylinkedlocation. YoucontrolwhichdevicesarelinkedtotheVM,thereforecontrollingthemanagementof dataandreducingthepotentiallossofintellectualproperty.Youcansignificantlyreduce thecostofeachdesktop,sometimesbyasmuchas40percent.Youcanreducethenumberofimagestomanage,especiallywhenyouworkwithvolatilePCimages.Machines areeasiertopatchandupdatesinceyouoftenonlyhaveonecoreimagetoupdate.
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Basically, VDI transforms the desktop life cycle and reduces its components (see Figure10-10).Traditionally,youmustprocure,image,secure,deployandthenmonitor, maintain,backup,andeventuallyretireyourphysicaldesktops.WithVDI,youonly needtogeneratetheoriginalimagethroughthecreationofareferencecomputer,useit asthecoreimageforallsystems,personalizeit(whichisusuallyperformedbytheVDI engine),thenmonitorandupdateit.Imagesareautomaticallyretiredbythedesktop brokerwhentheuserlogsoff. However, using technologies such as XenDesktop and others does present a challenge in terms of PC image construction and management. Ideally, organizations will requireasinglePCimage,asoutlinedearlierwhendiscussingthePASSsystemconstructionmodel.Usingonesingleimagetomeeteachandeveryuser’sneedsmeansthatyou havetodeviseasystemthatwillautomaticallyprovisiontheimagewiththerequiredapplicationsanduserdataatlogon.Thebestwaytodothisistorelyonapplicationvirtualization(coveredinthenextchapter)anduserprofileprotectionmechanisms(covered inChapter12).UserprofiledataabsolutelymustbestoredoutsidethePCimageifitisto beprotected.XenDesktopdidnotofferthisfeatureatthetimeofwriting,butCitrixobviouslyintendstoprovideitsometimeinthefuture.Windows,however,alreadyoffersa profileprotectionmechanismthroughroamingprofilesandfolderredirection. Applicationprovisioningismorecomplicatedsinceitrequirestheabilitytoprovide theenduserwiththeapplicationstheyneedwhentheyneedthem.Usingtraditionalapplicationdeliverymethodswillnotworksincetheytaketimetoinstallanddeploy.Ifthis wasthemethodyouused,youruserswouldbecompletelydissatisfiedwithVDIasthey waitedforlongperiodsoftimeatloginastheapplicationstheyrequiredwereattached tothedesktopimage.ThisiswhyVDIdoesnotworkonitsown.Itabsolutelymustbe tiedtoapplicationvirtualizationtomakeitwork.Keepthisinmindwhenyouprepare andchooseyourdesktopvirtualizationsolution.
Figure10-10. ThetraditionalPClifecycleversustheVDIlifecycle
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MajorVendorPositioning Asyouhaveseen,thereareseveralsolutionsfordesktopvirtualization.Onceagain,the threemajorvendorsoffersimilarsolutions,buteachhassomethinguniquetooffer.In addition,therearethird-partysolutionsthatsometimesoffercompletelydifferentapproaches to the problem. Of these, InstallFree is the most innovative because they do notuseavirtualizationengineontheback-end.Thismightbetherightchoiceifyoudo nothaveorintendtoputaservervirtualizationsolutioninplace.However,organizationswithoutservervirtualizationsolutionswillberareandfewinthecomingyears. MicrosoftofferspresentationvirtualizationthroughitsTerminalServicesfeature.Citrix offerspowerfulenterprisedesktopvirtualizationandcanrunonanyback-endplatform. VMwarehasthemostmaturesolution,especiallysinceVMwareViewisnowavailable. Considertheseoptionswhenyouchooseasolution.
MaketheDesktopVirtualizationDecision Remember that there are several different solutions for desktop virtualization. When you make the decision to virtualize desktops, you should consider the business need firstandthenthesolutionyoushouldapplytotheproblem(seeFigure10-11).Ifyou needtorunapplicationsthataresharable,perhapsthebestsolutionissimplytoimplementpresentationvirtualization,somethingmanyorganizationsalreadyhaveinplace. Ifyouwanttosecureandcentralizedata,chooseavirtualdesktopinfrastructure.Ifyour usersneedtohaveofflineaccesstovirtualdesktops,chooseasecureandencryptedsolutiontohavetheVMrunontheirowndesktop. Remember,however,thatVDIanddesktopvirtualizationoftendoesnotworkonits ownandrequiresadditionalcomponents,componentsthatarecoveredinfuturechapters.VDIisapowerfulsolutionthatreducesdesktopmanagementcostsandisdefinitely part of the dynamic datacenter. Once again, you’ll find that you’ll learn more as you implementandusethissolution.
Figure10-11. TheDesktopVirtualizationDecisionProcess
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O
ne of the most demanding aspects of distributed systems management is software asset management—the science of tagging, packaging, deploying, and maintaining software assets in your organization. Depending on your organization’s size, you may have from a dozen to several hundred applications in operationinyournetwork.Packagingandtestingeachoftheseapplicationstoensure theywillproperlycohabitatewithothersonthesametargetsystemisoneofthebiggest tasksadministratorsface.What’sworse,thistaskmustberepeatedeachtimeyouchange operatingsystems,makingitoneofthemostoneroustasksinITtoday. Traditionally,organizationsmanageendpointsthroughlayeredapproaches,buildingfirsttheoperatingsystem,andthenapplyingcoreoperatingsystemutilities,such asdiskdefragmentation,antispamandantivirustools,andanyothercorecomponent thatmustbeoneverysystemintheorganization.OncethecoreOSisready,applications are deployed, also in layers. The first application layer deals with applications everyoneintheorganizationrequires—toolssuchasMicrosoftOffice,graphicsviewers,databaseengines,andmore.Thesecondlayerdealswithspecializedapplications, whichrelatetotheparticularfunctionauserperformswithintheorganization:graphic designersrequireadvancedgraphicstools,applicationdevelopersrequireapplication constructiontools,financeusersrequirecustommoneymanagementtools,andsoon. Sincetheseuserfunctionsarenotwidespreadthroughouttheorganization,thissecond layerisdeployedonlytospecificgroupsofmachines.Finally,thelastapplicationlayer isdeployedonanadhocbasisasdifferentusersrequirehighlyspecifictools.Thisisthe structureofthePointofAccessforSecureServices(PASS)systemconstructionmodel outlinedinChapter10. Applicationsmustbecategorizedinthiswaytoavoidconflictsandreduceapplicationmanagementandsupportoverhead.Buttoday,thankstovirtualizationtechnologies,thereisabetterway.
APPLICATIONMANAGEMENTISSUES ThebasicstructureofWindowsisalsothecauseofmanyofthewoesadministratorsface withapplications.Windowsservesasthefoundationforapplicationoperation.Features such as application information exchange, application interaction, printing, graphical display, communications, and more are all embedded into the core operating system. Applicationdevelopersdonotneedtoprogramthesefeaturesintotheirapplications, onlylearntocallonthemwhenrequired.However,developersoftenlearnthatthecore componentstheycallupon,theDynamicLinkedLibraries(DLL)withinWindows,are subjecttochangeonaregularbasis.Sometimesthesechangeswillmaketheircallsno longerwork.Toprotecttheoperationoftheapplication,thedevelopertendstointegrate the Windows DLL into the installation of the application, sometimes replacing newer componentsonthetargetmachine.ThereplacedDLLwillworkfortheirapplication,but willnolongerworkforothers,causingtheirapplicationstobreak. DLLconflicts arethebaneofallsystemadministratorsandarecommonlyknown asDLLHell.DLLsareattheheartofallexecutables.Theseconflictsarisewhentheapplicationmanufacturersdecidetoincludesharedcomponentswithintheirapplication.
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Because of this, application administrators have learned that the best way to manage applicationsistoexamineeachofthecomponentstheyinstallandcomparethemtoall oftheothercomponentsonasystemtoavoidandproactivelyrepairconflicts.Buttoreducethisapplicationmanagementoverhead,administratorscategorizeapplicationsand makesureasfewaspossiblecancoexistononesystematatime. Because of this, organizations must manage several application categories: newly releasedcommercialapplications,legacycommercialapplications,andupdatedornew customapplications—applicationsthataredevelopedin-house,legacycustomapplications,andcustomcommercialapplications(formanufacturing).Legacyapplicationsare subjecttoDLLHellthemost,andnewapplicationsaresubjecttootherpotentialconflict types.Allmustbemanaged.
TraditionalApplicationManagementSolutions DLLHellhascausedadministratorsanddevelopersaliketocomeupwithavarietyof methodsforsolvingtheapplicationmanagementheadache.First,theyhavetakenthe timetoidentifyandintegrateapplicationsintoalifecycle.Then,theyrelyonthislife cycle to work with the Windows Installer service—a service Microsoft has integrated intoWindowstohelpstandardizeapplicationinstallations.Anothersolutionistoinstall applicationsonserversandpresentthemtousersthroughserver-basedcomputingor presentation virtualization. However, each approach has its own issues and none is a perfectsolution.
RelyontheApplicationLifeCycle Allapplications,nomattertheircategory,havealifecycle,andorganizationsmustmanagetheapplicationsthroughouttheirlifecycle(seeFigure11-1).Thelifecycleincludes four phases. The first deals with application acquisition or, if the application is built in-house, application requirements and the need for the application in the first place.
Figure11-1. Thetraditionalapplicationlifecycle
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Theseconddealswithimplementation.Thisiswheremostoftheproactiveworkagainst DLLHellisperformedastheapplicationispreparedfordeployment.Thethirddeals withapplicationmaintenance,andthelastdealswithapplicationretirement.Unfortunately,thislastactivityisrarelyperformed,asorganizationsdonotremoveobsoleteapplicationsfromsystems—everyonehasthe“youneverknowwhatremovinganapplicationmightdestabilize”attitude—andpreferstoreimagesystemsonaregularbasis.
WorkwithWindowsInstaller To help organizations properly manage applications throughout their life cycle and alsotohelpstandardizeapplicationinstallationsinWindows,Microsoftdevelopedthe WindowsInstallerservice(WIS).WISisatoolthatsupportstheinstallationofsoftware throughtheuseofaconsistencydatabase.Eachproducthasitsownconsistencydatabase.Thisdatabaseisusedtoprovidecomprehensiveapplicationinstallationsupport features.Featuressuchasself-healing,applicationinstallationmonitoring,application installationrollbackonfailure,andmoreareallpartoftheWISfeatureset.However, understandingandworkingwithWISisanartinandofitself. NOTE For comprehensive information on theWindows Installer service and its inner workings, downloadthefreewhitepapertitledWorkingwithWindowsInstallerfromwww.reso-net.com/articles .asp?m=8#p. ToproperlymanageWindowsInstaller,systemadministratorsneedtopackageapplications in the MSI format. To do that, they can rely on commercial tools such as AltirisWisePackageStudioorInstallShieldAdminStudiofromAcressoSoftware.WIS isdesignedtoremoveDLLconflictsfromapplicationinstallations,butitdoesnotsolve allproblemsbecauseotherconflictscontinuetoexist.Thisiswhyapplicationconflict detectionisstillnecessary,evenwithMSIpackages.Conflictdetectionshouldcover thefollowingitems(seeFigure11-2):
▼ Productcomponents
■ Productfiles
■ Registryentries
■ ShortcutsandINIfiles
■ OpenDatabaseConnectivity(ODBC)resources
■ NTservices
■ Fileextensions
■ Productproperties
▲ OSkerneldrivers
EachoftheseitemsispartoftheWISstandard,buteachcanbeacauseforissueswhen anapplicationisdeployedwithoutfirstverifyingandsometimesrepairingtheseitems withintheMSIyoucreatetoautomateapplicationdeployment.
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Figure11-2. MSIconflictdetectionisnecessary,evenifyouuseasystemstacksuchasthe PASSmodel.
EventhoughMicrosofthasimprovedWISthroughoutthevariousreleasesofWindows,itstillhassomeissues.Forexample,ifyouarethinkingofmovingtoWindowsVista,youwillneedtoworkwithWindowsInstaller4.5.VistareliesontheRestartManager tostopandrestarttheapplicationswheninstallationsrequireit.Inaddition,Windows InstallerisintegratedwithUserAccountControl,theapplicationsareautomaticallyinstalledwithelevatedprivileges,andtheyarestoredinWindows’HKEY_Local_Machine registryhive,thesameasusingALLUSERS=1propertythroughtheWIScommandinterface:msiexec.exe.Inaddition,applicationsintegratedwithWIS4.5mustbedigitally signedifyouaretosupportapplicationpatchinginstandardusermode.And,becauseof thenewWindowsResourceProtectionfeatureinWindowsVista,WindowsInstallerwill skiptheinstallationofsystemfilesiftheyarecontainedwithinapackageandthenlogan entryintothelogfilebeforecontinuingtheinstallation.
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UseanApplicationPackagingProcess WorkingwithWIS,thoughitdoesresolveseverallegacyinstallationissues,meansusing acomprehensiveapplicationpreparationprocess(seeFigure11-3).Thisprocessismade upoffivedistinctivesteps,whichcanbeperformedbyteamsoftechniciansinaprocess similartomanufacturing.Eachteammemberperformsataskandhandsoffthepackage toanotherthroughthisworkflow.
Figure11-3. Workwithasoftwarepackagingprocess
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Steponecentersonrequestmanagement.Ifyourorganizationisfocusedonapplicationmanagementissuereduction,thisstepwillincludearationalizationstrategytoensurethatonlyapplicationsthatareabsolutelyrequiredareintroducedintothesystem. Steptwopreparesproductintegrationandbeginstheapplicationanalysisprocess. Whataretheapplicationrequirements?Doesitintegratewithothers?Whatisitsinstallationprocess?Theseareallquestionsthatthisstepaimstoanswerbeforethepackageis createdandisreadytomoveontothenextstage. Step three tests the initial package to ensure that it works properly and has been integratedwithyourorganization’ssecurityandotherstandards.Itfinishesoffwiththe automationofthepackage. Stepfourperformsqualityassurance(QA)onthepackage,testingbothremoteand interactiveinstallations,identifyingifconflictsremainandifthepackagecanberemoved withoutissuesremainingonthetargetsystem. OncethepackagehaspassedthroughQA,itmovesontoreleasemanagementand thenitisreadyfordeployment.Thepackageisfullydocumentedandisintegratedwith thesoftwarerepositoryinyournetwork.Itisthendeployedtoalltargetsystems. Asyoucansee,whileWISdoeshelpprotectsystems,preparingMSIpackagesisa comprehensivetaskthatrequiresplanningandforethought.
WorkwithPresentationVirtualization WhenpackagesarepreparedinMSIformat,theyareoftendeployedthroughtraditional electronic software distribution (ESD) systems to all target machines. For example, to deployMicrosoftOffice,organizationsoftensendoutmorethan500megabytes(MB)of datathroughunicastcommunicationstohundredsofdistributedPCs.Then,oncetheOfficeinstallationisoneachofthesedistributednodes,theseorganizationshavetomanage itsupdateandmaintenancethroughoutitslifecycle. Suchdeploymentscancausealotofissues.First,thebandwidthrequiredforthedeploymentismassive,asisthetimewindowrequiredtoactuallyperformthedeployment. Then,sincemanyorganizationshavegrantedtheiruserslocaladministrativerights,the applicationtheydeployedinapristinestateisoftenmodifiedbeyondrecognition,causingmoreissues.Also,localdiskdrivesfailandsystemsneedtobereimaged.Service packs need to be deployed to maintain Office, and these service packs are sometimes evenlargerthantheoriginaldeployment. Becauseoftheseissues,manyorganizationshavemovedtoserver-basedcomputing, or presentation virtualization (PresentV). PresentV relies on server-based installations thataresharedamongmultipleusers.Thisstrategyprovidesmanybenefits.
▼ B ecausethesoftwareisinstalledonaserver,thereareonlyafewlocations whereconflictscanarise.Thisreducestheconflictmanagementoverhead.
■ Therearealsoonlyafewlocationstoupdateandmaintain.
■ B ut,youstillneedtouseMSIsasmuchaspossibletomaintaintheWIS advantage.However,theseapplicationsmustbeinstalledinsharedmode.
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▲ A nd,ifyourelyonthebuilt-inPresentVfeaturesofWindowsServer,especially WindowsServer2008(WS08),therearenoadditionalcommercialsystems requiredtomakePresentVwork.WS08hastheabilitytopublishserverbasedapplicationsonaone-by-onebasis,makingtheexperiencecompletely transparenttoendusers.
WindowsreliesontheRemoteDesktopProtocol(RDP)toprovideaccesstotheseremote applications.PriortoWS08,Microsoft’sTerminalServicesprovideduserswithaccessto acompleteremotedesktop,whichcouldbeconfusing.Becauseofthis,manyorganizationsoptedtoimplementCitrix’sremoteapplicationsolution,thencalledPresentation Server. Presentation Server provided one-to-one access to applications, making them lookasiftheywereactuallyinstalledonthedesktop.Citrixhassinceupdatedthename ofPresentationServertoXenApp;however,notallcustomershaveoptedtoupgradeto thisversion. WithWS08,Microsofthasintegratedthesameorsimilarfeaturestopublishonlyapplications.However,evenwiththisimprovement,therearestillissueswithserver-based computing.
▼ M obileusersdonothaveaccesstocentralizedapplicationswhentheyareon theroad.
■ S erver-basedcomputingonlyworksforconnectedsystems.Disconnected systemsdonothaveaccesstoremoteapplications.
▲ S erver-basedcomputingrequiresmassiveserverconfigurationsandlarge serverfarmstomaketheapplicationshighlyavailable.
Because applications are shared and multiple users access them remotely, the servers thathostthemmusthavemassiveprocessingpower,aconfigurationthatisnormally reservedforhostserversrunninghypervisors. Asyoucansee,traditionalapplicationmanagement,whetheritisondistributedsystemsoronremoteservers,canstillcausealotofissues,especiallyifitisn’tdoneright.
REDESIGNAPPLICATIONMANAGEMENT Fortunately,withtheintroductionofvirtualizationtechnologies,thereisnowabetter way to manage applications, even distributed applications: application virtualization (AppV).Applicationvirtualizationtransformsthetraditionalapplicationmanagement processbyremovingallpossibilityofapplicationconflictsaswellastransformingthe deliverymechanismbyturningitintoapullratherthanapushmechanism.Withthe properAppV technology, your users will request applications when they need to use themandyouwillnolongerneedtodeploythebitsbeforehand.Theseareonlytwoof themajoradvantagesAppVprovides.
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WorkwithaVirtualizationLayer Whileapplicationvirtualizationwasintroducedseveralyearsago,ithasn’tyetbecome mainstream.Organizationscontinuetoconcentrateontraditionalsoftwaremanagement andinstallationprocedures,buildingsoftwarepackagesforWISandrelyingonESDsystemstodeploythesepackagestoendpoints.Buttoday,asvirtualizationbecomesacore aspectofdatacentermanagementstrategiesaroundtheworld,applicationvirtualization is also taking its place at center stage as systems administrators realize the powerful benefitsitbringstodistributedsystemsmanagement. That’sbecauseAppVprovidestheabilitytomaintainapristineoperatingsystem, despitethefactthattheOSrunsamultitudeofsoftwarepackages.Thisisdefinitelya boontoallorganizationsandadministratorseverywherearebeginningtobankonthis featuretoconsiderablyreduceapplicationmanagementandsupportcosts. Basically,applicationvirtualizationcreatesaprotectivelayeraroundtheoperating systemtosafeguarditagainstanychangesthatcouldbemadebyactuallyinstallingan application.ThecoreconceptofAppVisthatinsteadofcapturingasoftwareinstallation, suchaswhenpackaginginstallationsfortheWindowsInstallerservice,AppVcaptures therunningstateofanapplication.Itisthisrunningstatethatisthen“installed”onthe targetsystem,butsinceitisarunningstateandnotanactualinstallation,nochangesare madetotheoperatingsystem,except,ofcourse,forthenewfilesthatresideonit. Theapplicationvirtualizationlayertranslatesthisrunningstateintoinstructionsthe operatingsystemandotherapplicationscanunderstandandinteractwith,keepingthe coreOSpristineatalltimesandcontainingapplicationcomponentsinsuchawaythat theycannevercauseconflictswithotherapplications.Traditionalapplicationinstallationspenetratetheoperatingsystemandchangeitsconfiguration,butAppVprotectsthe operatingsystemfromanymodifications(seeFigure11-4). AppV completely isolates applications from both the operating system and from other applications by protecting the OS from file system and registry changes. Yet theapplicationwillcontinuetointeractnormallywiththeOSandotherapplications. Because of this, AppV allows different versions of applications to coexist with each otheronthesamesystemwithoutissue.AppVfullysupportstheabilitytorunnotoriouslyconflictingapplications,suchasMicrosoftAccess97,AccessXP,Access2003,and Access2007,onthesamesystem,atthesametimeandthenevenletsyoucutandpaste contentsfromonetotheother,provingthateachonecancontinuetointeractproperly withtheother. AnotherpowerfuladvantageofAppVisthatitcanbebothastand-alonesolution— workingonitsownonindividualsystems—oritcanbeintegratedintobothtraditional (pushinstallations)andstreaming(pullinstallations)softwaredeliverysolutions.When usedwithtraditionalESDsystems,AppVdeliversthefullyconfiguredapplicationtothe endpoint.Butwhenitisusedinconjunctionwithastreamingsystem,onlythebitsthat arerequiredtorunthebaseapplicationfunctionalitywillbedeliveredatfirst—usually lessthan10percentoftheapplication—andtheremainderoftheapplicationcomponents willbedeliveredondemandasusersworkwithmoreoftheapplication’sfunctionsand features.Betteryet,onlytheapplicationstheenduseractuallyworkswithwillbedelivered.Iftheuserdoesnotrequireanapplicationduringasession,nobitsaredelivered.
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Figure11-4. AppVcreatesaprotectivelayertosafeguardtheOSfromchanges.
However,inordertocreateacompletesystemsmanagementstrategy,organizations shouldconsidertheuseofallthreeelementsintheirITinfrastructure.
▼ A ppVhelpsresolveallofthemostcommonissuesrelatedtoapplicationusage andmanagementwhilemaintainingtheintegrityofendpointsystems.
■ S treamingsystemshelpdeployapplicationsandupdatestoendpointsona just-in-timeandjust-enoughbasis.
▲ E SDhelpsmaintainandmanagethemoretraditionalcomponentsofyourIT infrastructure—coredesktoputilitiesandservices,server-baseddeployments, and,iftheoptionisavailableinthetoolyouchoosetouse,operatingsystem deploymentsandupdates.
ESDisusedforcoreOSandutilityupdates,streamingisusedforapplicationdelivery,and AppVisusedtoprotectallsystemsatalltimes.Thismakesforapowerfulcombination.
TheComponentsofAppV Thereareseveralproductsonthemarketthatcanhelpmaketheapplicationmanagement pain go away once and for all becauseAppV packages are independent of the
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underlyingoperatingsystem.Theprocessissimple.Beginbypreparinganapplication forvirtualization.Todoso,youcapturetherunningstateoftheapplicationandstore itinanAppVpackage.Thispackagecontainsallofthefiles,processes,andsettingsrequiredtoruntheapplication.Eachapplicationiscapturedintoaspecificpackagethat willthenbedeployedtoatargetsystem.Next,youmakethepackageavailabletothe endpoints,eitherthroughtraditionalESDsystemsorthroughstreamingtechnologies. Because of their reduced overhead, streaming systems are preferred since they only providetheapplication’sshortcuttothesystemandbitsaredeployedonlywhenthe userclickstheshortcut. SincetheAppVpackagesarecapturedintheirrunningstate,usersoradministrators canresetthemtotheiroriginalstateintheeventthatanuntowardincidentoccurs.When itistimetoretiretheapplication,simplydeleteitfromthesystem.Nowthatisamuch simplerapplicationlifecycle. WhenyouselectyourAppVsolution,youshouldlookforseveralfeatures,including:
▼ Applicationisolationorsandboxing
■ Windowsversionindependence
■ Agentversusagentlessoperation
■ Activationornonactivationsupport
■ Streamingdeliverymechanisms
■ EndpointAppVcachecontrol
■ ActiveDirectoryintegration
■ Licensecontrol
■ Productionproject-basedpackaging
▲ SoftwareasaService(SAAS)support
Eachoftheseprovidesextensivefunctionalitythatreducestheoverallapplicationmanagementlifecycleandremovesmanyofitsheadaches.
TheAppVSystemStack Chapter10outlinedhowtraditionaldesktopsareconstructedthroughthePASSmodel. However,becauseAppVprovidesprotectionfortheoperatingsystemandbecauseAppV canworkwithstreamingtechnologiestoprovideapplicationsondemand,organizations movingtoapplicationvirtualizationwillwanttoredesignthePASSmodelandmoveto athinsystemkernel(seeFigure11-5).Thecoreofthesystemconstructionmodel,the kernel,isnowreducedinsizeandonlyincludesthefollowingitems:
▼ Thecoreoperatingsystemanditsrequiredupdates.
■ C oreutilities,suchasantivirus,antispyware,firewalls,managementagents, andvirtualizationagentsiftheyarerequired.
▲ Fromthenon,youvirtualizeeverythingelse.
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Theapplicationlayersaretransformedintothreelayers.ThePASSsystemkernelandthe generalizedapplicationlayer(GAL)meettheneedsoftheaverageorgenericuser.Rolebasedapplicationsandthecommercialsoftwareareaddedontopofthenewthinkernel tomeettherequirementsofthespecialITroles,andfinally,theadhoclayerresponds tohighlyspecializedITrequirements.Withthissystemstack,thekernelorthecoreOS stayspristineatalltimes;basically,itstaysthewayyoubuiltit.
Figure11-5. UsingacombinationofAppVandstreamingcancompletelytransformtheendpoint constructionmodel.
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WindowsVersionIndependence Besides transforming the system construction model, AppV reduces the application packagingeffortbecauseofthewayitworks.EachAppVsystemcansupportmultiple versionsofWindows.ThismeansthatwhenyoupackageanapplicationforAppV,you neverneedtopackageitagain. BecausetheAppVenginemanagesalltransactionsbetweentheapplicationandthe OS,ithastheabilitytotranslatetheseinstructionsintotheformatrequiredbyaspecific targetOS.SomeAppVproductswillgoasfarbackasWindowsNTandallowyoutorun anAppVpackagefromNTthroughWindows2000,XP,andVista. This feature alone is worth its weight in gold. Traditionally, application packagers mustrevisittheapplicationeachtimeanewOSisreleasedandtheirorganizationhas selectedtodeployit.Thisactivityisthesinglemostexpensiveapplicationmanagement activityorganizationsfacewhenchoosingtoupgradedesktopoperatingsystemsandis oneofthemajorreasonswhyWindowsVistahasnotseentheexpectedrateofadoption. But,becauseofWindowsOSindependence,AppVpackageswillsimplyrunonVista eveniftheywereoriginallycreatedforWindowsXP.ThesamewillapplywhenMicrosoftreleasesWindows7.Youwill,ofcourse,havetowaituntiltheAppVengineyourely onhasbeenupgradedtoworkwithWindows7,butyoushouldnothavetorevisiteach AppVpackage. Thismakesitmuch,mucheasiertoupgradeoperatingsystemsandgreatlyreduces thecostofnewOSdeployments.
AgentVersusAgentlessAppV AppV engines come in two flavors. The first is agent-based, requiring a predeployed agentonthetargetsystemtorunthevirtualizedapplicationsandtocommunicatewith thecentralAppVrepository.Thesecondisagentless,orrather,theagentiseitherembeddedwithinthevirtualizedapplicationortheagentiscarriedwiththeapplication.Both havetheiradvantagesanddrawbacks. Agent-basedAppVmeansthattheagentmustbeavailablebeforethevirtualizedapplicationscanrun.Thismeansthattheagentmustbedeployedthroughastandardelectronicsoftwaredistributiontool,installedwiththecoreOS,or,insomecases,deployed through the streaming engine. In the latter case, the streaming engine itself requires a localagent,whichmustalsobepredeployed.Inaway,agent-basedAppVisaprotection mechanismbecausetheapplicationsyouvirtualizewillnotrununlesstheagentisavailable.RememberthatanapplicationthatisvirtualizedwillrunonanyversionofWindows andonanysystem.IfyourAppVengineisagent-based,yourapplicationsareprotected, sinceamalicioususerwantingtowalkawaywithyourapplicationswouldsomehowalso needtoobtainandhavetheabilitytoinstalltheagentbeforebeingabletousethem. DeployingagentsisnotadifficulttasksincethethinPASSkernelwillusuallyrequire otheragentsandutilitieswithinthecoreOSimage,suchas:
▼ Inventoryagenttokeeptrackofallsystems.
■ E SDagenttosupportsoftwaredeploymentforexample,theActiveDirectory deploymentagentistheGroupPolicyclientthatisalreadypartofWindows.
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■ P atchdeploymentagentonceagain,theWindowspatchingagentisthe WindowsUpdateClient,whichisalsopartofWindows.
■ A ntivirusandantimalwareonceagain,theantimalwareagentinWindowsis WindowsDefender.
▲ SearchengineinWindows,thiswouldbeWindowsSearchorathird-partytool.
Butevenifyourcoresystemrequiresanagent,oraseriesofagents,managingtheseutilitiesisstillmuch,muchsimplerthanmanagingtraditionalapplications. Agentless AppV (where the agent is embedded into the virtualized application) means that the virtualized application transports the engine with it and can run as-is onanyWindowsplatform.Theadvantageisthatyoudonotneedtoworryaboutpredeployingagents.TheseAppVapplicationsarecompletelytransportableandwillrun on any system with nothing more than standard user rights. This includes your own locked-downsystems,publicsystems,kioskcomputers,andmore.Userscantransport their entire application environment—for example, Microsoft Office, along with their documents—onaUniversalSerialBus(USB)key.Theycanactivatetheirapplicationson anycomputersimplybypluggingintheUSBkeyandlaunchingtheapplication. Thisisapowerfulmodel;butontheotherhand,youdoneedtoworryaboutapplicationsecurity.AgentlessAppVapplicationsarecompletelytransportable.Thismeans thatanyusercancopyanagentlessAppVapplicationandtakeittoanysystemtorun it.Additionalmeansmustbetakentoprotecttheseapplicationsifyoudon’twantyour licensesspreadeverywhere.Thismeansthatyoumustembedlicensesandlicenseprotectionmechanismswithinthepackagedapplicationtoensurethattheyonlyruninyour environment.
LocalRepositoryManagement EachAppVtechnology,whetheragent-basedoragentless,reliesonalocalcachetorun theapplication.Whentheapplicationisactivated,theapplication’sbitsaremadeavailablelocallytoruntheapplication.Thislocalrepositoryisatemporarycontainerforthe application.Itcanbevolatile,thatis,thecacheisclearedassoonastheuserlogsoff.It canbetemporary,thatis,thecacheisavailableonatimedbasis.Forexample,ifyour teamisworkingonaprojectforthreemonths,yougivethemathree-month-longcache ofMicrosoftProject.Afterthethree-monthperiod,thecacheisautomaticallyclearedand theapplicationisnolongeravailable.Thecachecanalsobesettosemipermanent,which meansthatitwillnotexpireuntilyoumanuallymodifyit.Thislattermodeisusefulfor mobilecomputerswhichneedaccesstotheapplicationwhethertheyareconnectedor disconnected. Usingcachecontrolsallowsyoutomaketheapplicationsaspersistentasyouneed themtobe.And,becausetheapplicationisnotactuallydeployedtothetargetsystem, whenitcomestimetoupdatetheapplication,simplyupdatethecentralrepository.The nexttimetheapplicationislaunched,thesystemwillverifywiththecentralrepository toseeifanychangesweremadeand,ifso,itwillautomaticallyupdatethelocalcache, updatingtheapplicationatthesametime.
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Applicationscanbealsobeprecachedandthenactivatedasneeded.Theapplicationsdonotgetinstalledoraltertheoperatingsystem;youcanevenuseXCopytoplace thebitsonthetargetsystemsinceno“installation”isrequired,yettasksprocesslocally onthehostcomputerasiftheapplicationswereinstalled.
ActiveDirectoryIntegration MostAppVtechnologieswillintegratedirectlywithActiveDirectory,allowingyouto assignAppVapplicationsthroughsecuritygroupassignments.Createagroup,attachit toanapplicationassignmentintheAppVmanagementtool,andthensimplyassignapplicationsbyplacinguseraccountswithinthegroup. Whiletraditionalapplicationsmustbeassignedtocomputers—otherwisetheinstallationswillalwaysoccureachtimeauserlogsin—thisruledoesnotapplytoAppVapplications.SincetheAppVapplicationisnotdeployedinthetraditionalsense,youcan assignittousers.AppVapplicationsareonlydeployedwhentheuseractivatesthemby double-clickingtheapplication’sshortcut.Whentheuser’saccountisaddedtoanActive Directory(AD)grouplinkedtotheapplication,theshortcutisautomaticallydisplayed onthedesktop.Then,todeterminehowmanylicensesareassignedfortheapplication, allyouneedtodoisfindouthowmanyusersareintheapplication’sgroup. ToassignapplicationsaccordingtotheapplicationlayersinthethinPASSmodel, youcanuseaflowchartdecisionprocess(seeFigure11-6).Ifanapplicationiscontained withintheglobalapplicationlayer(GAL),itisassignedtoallusers.Ifitisintherolebasedlayer,itisassignedtospecificgroupswhoserolecorrespondstothegrouping;ifit isanadhocapplication,itisassignedtoindividualusers.
Figure11-6. AssigningAppVapplicationsthroughActiveDirectorysecuritygroups
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AppVSoftwarePackaging Packagingisalsocompletelydifferent.Inthetraditionalpackagingprocess,youmust alwaysreturntoapristineoperatingsystemeachtimeyoustartanewproject.Butwith AppV,sincetheapplicationisn’treallyinstalledonthesystemandyouonlycapturethe runningstate,youdonotneedtobeasstrictwiththeenvironment.Thevirtualapplicationpackagingprocessisolatesthesoftwarebecauseallsystemcomponentsarevirtualized. Applications are packaged in a special format that “sandboxes” applications to providecompleteisolationfromthesystem. And then, once the applications are packaged, they are placed in a core software repositoryfromwhichtheyarepulledtoendpointsbyendusers.Ifyouhavemultiple sites,yousimplyreplicatethisrepositoryasneededtowhereveritisrequired.Forexample,inaWindowsenvironment,youcouldusetheDistributedFileSystemReplication (DFSR)engine,whichisadeltacompressionreplicationenginethatwillreplicateonly changesfromonelocationtoanother. NOTE For more information on DFSR, look up MicrosoftWindows Server 2008:The Complete ReferencebyRuestandRuest(McGraw-Hill,2008). AppVpackaging,however,muststillbestructuredandmustincludequalitycontrol (seeFigure11-7).You’llnoteamajordifferenceintheprocesscomparedtotraditional packaging:ThereisnomoreneedtoperformconflictdetectionsinceAppVisolatesall applications.Thisisagreatbenefitand,coupledwiththefactthatyounolongerneedto updatepackageseachtimeyouchangeoperatingsystems,isagreattime-saver.
RunSoftwareasaService Finally,AppV supports the Software as a Service model since you can provideAppV applications on demand. AppV also supports self-service software provisioning and on-demanddelivery.Simplysetupawebpagewithlinkstoapplications,allowusers torequesttheirownapplications,integrateaworkflowtodemandauthorizationfrom managerstopayfortheapplication’slicense,andautomaticallyaddtheuser’saccount intheapplicationgrouponcetheauthorizationhasbeenprocessed.
Figure11-7. TheAppVpackagingprocess
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Inaddition,applicationsarecompletelytransportable.Youcandeliverthemthrough networkshares,evenusingofflinefilesinWindowstocachethemlocallyonendpoints. YoucandeliverthemonUSBkeysorread-onlymedia,suchasCDsorDVDs.Youcan alsodeliverthemthroughwebpagesusingWebDAV,theHypertextTransferProtocol (HTTP),ortheFileTransferProtocol(FTP).Becauseofthis,traditionalsystemmanagementtoolsaredefinitelyoptionalwhenitcomestoAppV. Inaddition,therearetoolsonthemarketthatletyouconvertallofyourapplications fromtheWindowsInstallerMSIformattoAppV.IfyouhavetakenthetimetocreateMSIs forallofthesoftwareyoumanage,thismightbethebestwayforyoutomovetoAppV. NOTE Onetool,InstallShieldAdminStudio,willconvertMSIfilesinabatchprocessovernightand targettwoformats:CitrixXenApporVMwareThinApp.Moreformatsareintheworks.Learnmoreat www.Accresso.com.
ApplicationStreaming:ANewDistributionStrategy Asmentionedearlier,AppVenginesalsoincludeanewsoftwaredeliverymechanismas wellasabstractingsoftwarefromtheoperatingsystem.AppVpackagesarecapturedin aspecialstructurethattransformsapplicationpackagesinto4-kilobyte(Kb)segments, turningthemintostreamablecomponents—componentsthatcanbedividedintoseveral differentcategories,dependingontheengineyouuse.
▼ M ostenginessupportthestartupblock,orthecomponentsthatarerequired tolaunchtheapplicationandallowtheusertobeginworkingwithit.Inmany cases,thesecomponentsformlessthan10percentoftheentireapplication.For example,withMicrosoftWord,thiswouldbeenoughcodetolettheuserbegin typinginaneworexistingdocument.
■ S omeenginessupportasecondblocktype,predictiveblocks.Asusers throughouttheorganizationcontinuetoworkwithastreamedapplication,the streamingserveranalyzesusagedatatodeterminewhichapplicationblocks aremostcommonlyrequested.Theseblocksarethenidentifiedaspredictive blocksandaresettoautomaticstreamingtoendpointsforanyonewhohas activatedtheapplication.Whenuserswhohaven’tusedthefeaturescontained inthepredictiveblocksbegintoworkwiththem,theblocksarealreadyon thesystemandprovideevenbetterresponselevels.Predictiveblocksusually makeuplessthan10percentoftheapplicationandbeginstreamingassoonas thestartupblockdownloadiscomplete.
▲ A llenginessupportthefinalblocktype,on-demandblocks.Theseblocksare providedtoendusersonanon-demandbasis,mostlybecausethefeaturesthey containarerarelyusedanddonotwarrantprecachingonendpoints.
Theexperienceiscompletelytransparenttoendusers.Inmostcases,thestreamingenginedisplaysaniconinthesystemtrayatthelower-rightcornerofthescreen.Youcan, ifyouwant,havethestreamingagentdisplaystreamingeventstoendusers;however, hidingtheseeventsprovidesabetterend-userexperience.
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Figure11-8. AnAppVstreamingsystemarchitecture
Theapplicationsarepackagedinstreams;thisway,onlyafewbitsarerequiredfor theapplicationtostart.Forexample,MicrosoftOfficeismorethan500MB,butthrough thestreamingprocess,userscanrunWordwithonly9MB,andthisstartupblockisusuallystreamedtothedesktopinlessthantenseconds. Asmentionedearlier,streamedapplicationsarecachedlocally,soallusershaveaccesstothemaslongastheirprofileorActiveDirectoryaccessrightsallowit.Mobileusers havedisconnectedpermissionsandcantravelwiththeapplication.Thestreamingprocessdoesnotrequireacomplexinfrastructure;itcanoftenbeassimpleasafileserver;or ifyouhaveacompletestreamingengine,itisaservermuchlikeamediaserver.Because ofthis,infrastructurescanbemadehighlyavailablethroughtheuseoftechnologieslike theNetworkLoadBalancing(NLB)service,whichpresentsasingleaddresstoendpoints butrunsmultipleserverstoprovideservicecontinuity(seeFigure11-8).Databasesthat arerequiredtocontainmanagementdatacanalsobemadehighlyavailablethroughWindowsFailoverClusteringServices.
TheApplicationStreamingSystem Applicationstreamingsystemsprovideahostoffeaturestoorganizations.
▼ T hefirstison-demanddeployment.Byusingthestreamingconsole—a standardwebinterfaceaccessedthroughanybrowser—toidentifywhich
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userscanaccesswhichapplications,youautomaticallymaketheapplication’s shortcutavailableontheendpoint.That’sbecausethestreamingagentwill provisionauthorizedapplicationsonanyendpointtheuseraccesses.Then, whentheuserlaunchestheapplication,itwillautomaticallybestreamedto theendpointandreadytouseinseconds.Duringthestreamingprocess,the application’sstreamingshortcutisreplacedwiththeactualshortcut,again throughaprocessthatiscompletelytransparenttotheuser.
■ T hesecondisremoteaccess.Whenapplicationsareassignedtousers,the administratorcandetermineifitwillbecachedlocally.Ifyes,theapplication becomesavailableoffline.Ifnot,theapplicationisre-streamedeachtimethe useraccessesit.
▲ T hethirdislicensecontrol.Thestreamingagentautomaticallyreports applicationusageinrealtimetotheserveronanongoingbasis.Becauseofthis, anystreamedapplicationprovidesusagedataonaconstantbasis.Theresult isconstantlicensingcomplianceandconsiderablereductioninlicensingcosts, sometimesupto50percent,becauseyoucaneasilyandquicklyreharvest anyunusedlicense.Asyoucansee,dynamiclicensemanagementoffersa compellingbusinesscaseforitself.
ThesekeyfeaturesareprovidedalongsidetheotherconsiderablefeaturesAppVoffers. Forexample,endpointharddiskusageisconsiderablyreducedsinceonlyportionsof eachapplicationresideonthedisk.Applicationdistributioncannowbedoneeitheronlineoroffline.Applicationassignmentcanbeperformedthroughgroupmemberships inActiveDirectoryoranyotherLightweightDirectoryAccessProtocol(LDAP)directory;justplacetheuserinagroupandassigntheapplicationtothegroupinsteadof individualusers.Andtheentiresystemcaneasilybemaderedundantsinceitrelieson standardHTTPprotocolsandworksmuchlikeawebserver.
BENEFITSOFAPPVFORTHEORGANIZATION Applicationvirtualizationisoneofthemostcompellingtechnologiesavailabletodatacentersofanysizetoday.Whetheryou’reinanorganizationthathas20or20,000users, you’llprofitfromAppV.Onceitisinplace,yourstreaminginfrastructurecanscaleto meet any needs your organization faces. Even in the case of mergers or acquisitions, youcaneasilyupdateyourstreamingsystemtointegrateanynumberofnewclients, whethertheyarecentralizedordistributed. Becauseapplicationsarecachedlocally,usersalwayshaveaccesstothem,whether theyareconnectedornot.Ifyouneedtoupdatetheapplication,simplycreateanupdate packageanditwillautomaticallyupdatethenexttimetheuseraccessestheapplication. Keepinmindthatthestreamingenginewillnotreplacethewholeapplicationthewaya traditionallyinstalledapplicationwouldbereplaced;instead,itwillonlyreplacethebits thathavechanged,furtherreducingthedemandonbandwidth.
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Inaddition,applicationvirtualizationandstreamingprovidescompleteflexibility— flexibility that traditional systems management tools do not offer. Consider these keypoints:
▼ Manageability Yoursystemsaremanageablefromanypointinthe organizationsincethemanagementinterfaceisawebinterfaceandonly requiresawebbrowserforaccess.
■ S ecurity Allapplicationsarecompletelysecuresinceyourequireboth thestreamingandthevirtualizationagents—eitheronthesystemorwithin theAppVpackage—tooperate.Inaddition,youcanrelyontechnologies suchasActiveDirectorySoftwareRestrictionPoliciestodigitallysigneach applicationandensurethatonlyauthorizedapplicationsruninyournetwork infrastructure.
■ R esiliency Eachofthecomponentsofyourstreamingsystemcaneasilybe maderedundant,providingtheutmostinresiliency.
■ F lexibility Youcandynamicallymanagelicensesandeasilyreharvest unusedlicensestoredistributethemasneeded.Imaginetryingtodothiswith traditionallydeployedapplications.
■ D isasterrecovery Sinceapplicationbitsarepulledbyend-usersystems,users canrelyonanycomputerinyournetworkandimmediatelyhaveaccessto theapplicationstheyuse.Intheeventofadisaster,userscanevenaccesstheir applicationsthroughtheInternetandworkonremotesystems.Inaddition, AppVisidealforvirtualdesktopinfrastructures(VDIs),sinceitprovidesthe abilitytobuildsystemsdynamicallybasedonauser’sneeds.
■ P ortability Applicationsdonotneedtoresideonaparticularworkstation. Theycanbecachedornot,asyoudetermine.Sincelessthan10percentofthe applicationisrequiredtooperate,userscanbeprovisionedinminutes,ifnot seconds,onanysystem.
▲ Optimization Youcanfinallyoptimizeapplicationlicenseusageinyour organizationbecauseyouarealwaysawareofwhoisusingwhatinrealtime.
Endusersalsobenefitbecausetheyhavetheverybestapplicationexperience.Applicationsareupdatedwithouttheirknowledge,andbecauseeachapplicationisvirtualized, theywillneverfaceanapplicationconflictissueeveragain.Ifsomethinguntowardhappenswiththeapplication,simplyresetittoitsoriginalvirtualizedstateanditisready togoonceagain.
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A
pplicationvirtualization(AppV)offersmanybenefitsandmaywarrantimmediateadoption,butitrequiresredeploymentofalltheapplications.Thismeansreplacingtheapplicationsthatarealreadyrunning—uninstallingtheapplication andthenredeployingitasavirtualapplication—butuninstallingmayleavetheoperatingsysteminapotentiallyunstablestate.Theidealtimetodothisiswhendeployinga brand-new,“clean”computerinanoperatingsystemmigrationorinamovetovirtual desktopinfrastructure(VDI). You should start with baby steps and focus on the most problematic applications inyournetworktostart,andthenmovetoallapplicationsintime.It’sguaranteedyou would never go back to the “old” application installation model. But first, you must selectwhichAppVsolutiontoworkwith.
COMPAREAPPLICATIONVIRTUALIZATIONPRODUCTS Thereareseveraldifferenttypesofapplicationvirtualizationengines.Table12-1outlines several of the different products available on the market. Note that each of the three major virtualization vendors—Citrix, Microsoft, and VMware—offer AppV products.
Manufacturer
WebSite
Description
Ceedo
www.ceedo.com/ products/ceedoenterprise.html
Comesinthreeeditions.The EnterpriseEditionenablesmultiple applicationstobevirtualizedtogether tocreateavirtualworkenvironment. ThePersonalEditionenablesyou tocreateaportablevirtualdesktop comprisedofWindowsapplications, carryitwithyouonaUSB,portable harddrive,iPod,oranyotherportable storagegadgetandrunitonany PCwithoutinstallation.TheMobile Editionprovidesseamlessinteraction betweenthePCandthemobilephone, andenablesserviceprovidersto easilyextendtheirservicesintothe PC/Webplatformbylaunchingafull applicationsuiteonanyPCfroma mobilephoneoraSubscriberIdentity Module(SIM)equippedUSBdrive.
Table12-1. ApplicationVirtualizationTechnologiesandVendors
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Manufacturer
WebSite
Description
Citrix XenApp
www.citrix.com/English/ Combinespresentationand ps2/products/product applicationvirtualizationintoone .asp?contentID=186 product.Supportsapplication streamingtodesktopsorservers runningserver-basedcomputing services.Comesinseveraleditions (seeTable12-3laterinthischapter).
Endeavors Technologies Application Jukebox
www.endeavors .com/live/ showscreen.php?site_ id=23&screentype= folder&screenid=710
AppVandstreamingsystemfor Windows.Comesinthreeeditions: Enterprise,SoftwareasaService (SAAS),orLite.TheSAASEdition, inparticular,allowsInternet serviceproviders(ISPs)toprovide applicationsondemand.TheLite Editionisfreeandisusedtolet organizationstestoutAppVand streamingonasingleserver.
InstallFree Bridge
www.installfree .com/pageload .aspx?page=products_ InstallFree_Bridge.html
Clientlessplatformthatdeploys InstallFree’sVirtual(IFV)applications tothehostPCseamlesslyand transparentlytotheenduser,allowing virtualapplicationstofunctionas iftheywereinstalledonthehost computerwhileprotectingtheOS fromanychange.
LANDesk Application Virtualization
www.landesk.com/ SolutionServices/ product.aspx?id=776
LANDeskprovidesapplication virtualizationbycombiningits deploymenttechnologieswith VMware’sThinAppAppVengine.
Microsoft Application Virtualization (MSApp-V)
www.microsoft.com/ systemcenter/softgrid/ msappvirt45/default .mspx
FormerlyknownasSoftGrid ApplicationVirtualization,MS App-Vletsyoucontrolvirtual applicationsandstreamthemto endpoints.EndpointscanbePCs, virtualdesktops,orserversrunning presentationvirtualization.
Table12-1. ApplicationVirtualizationTechnologiesandVendors(continued)
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Manufacturer
WebSite
Description
Symantec Software Virtualization Solution(SVS) Professional
www.symantec.com/ business/products/ overview.jsp?pcid=pcat_ infrastruct_op&pvid=sv_ sol_pro_1
Placesapplicationsanddatainto managedunitscalledVirtual SoftwarePackages.Caninstantly activate,deactivate,orreset applicationsandavoidconflicts betweenapplicationswithoutaltering thebaseWindowsinstallation. Applicationstreamingprovidesthe on-demanddeliverymechanism.
TrigenceAE
www.trigence.com/ products/index.html
RunsonWindowsorLinux. EncapsulatesapplicationsattheOS level,creatingapplicationcapsules.
VMware ThinApp
http://vmware.com/ products/thinapp
FormerlyknownasThinstall ApplicationVirtualizationSuite, ThinAppletsyoupackageandrun applicationswithoutinstallation. ThinAppapplicationsexecute onlocked-downPCsinstandard usermode.
Xenocode Virtual Application Studio
www.xenocode.com/ Products/
AllowsWindows,.NET,andJavabasedapplicationstobedeployed incompact,preconfiguredvirtual executablesthatruninstantlyvia Web,USBkeys,orexistingdesktop managementinfrastructures.
Table12-1. ApplicationVirtualizationTechnologiesandVendors(continued)
Becauseofthis,itmaymakethemostsensetoselectthesamevendorforallaspectsof yourdatacentervirtualizationproject. Asyoucansee,thereareseveralpotentialAppVproviders.Theoneyouchoosewill dependonhowyouimplementyourvirtualinfrastructureandwhetheryouarereadyto movetoaVDIinfrastructure.Nomatterwhichsolutionyouchoose,however,applicationvirtualizationwillpayforitselfinaveryshorttimebecauseitmakesapplications independentoftheunderlyingoperatingsystem.Whetheryouuserealorvirtualdesktops,aprotecteddesktopisalwaysalessexpensivedesktop.Tofacilitateyourdecision, Table12-2comparestheofferingsfromthemostimportantAppVvendorsaccordingto
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Microsoft VMware App-V ThinApp
InstallFree Bridge
Applicationisolation,or x “sandboxing”
X
X
X
X
Windowsversion independence
X
X
X
X
X
Agent/agentless
X
X
X
Activation/no activation
X
x X
x
Cachecontrol–Timing/ X duration
X
X
x
Streaming
X
X
X
x
x
SoftwareasaService
X
X
X
X
X
ActiveDirectory integration
X
X
X
X
X
Licensecontrol
X
X
X
x
X
Productionprojectbasedpackaging
X
X
MSIconversionto AppV
X
X
x
Thinkernel
X
X
X
X
X
Globalapplicationlayer
X
X
X
X
X
Supportforrole-based/ adhocapplications
X
X
X
X
X
X
Table12-2. PotentialAppVSolutions
theAppVfeatureset.Withinthistable,alarge“X”meansthatthetoolfullysupportsthe feature,whileasmall“x”meansthatthefeatureisnotcompletelysupportedbythetool. Omissionsmeanthatthefeatureisnotavailablewithintheproduct. Asyoucansee,eachmajorproductsupportsmostoftheAppVfeatureset. NOTE For an up-to-date comparison matrix of several of these vendors, see The application virtualization solutions Overview and Feature Matrix by Ruben Spruijt at www.virtuall.nl/articles/ applicationanddesktopdelivery/ApplicationVirtualizationSolutionsOverviewandFeatureMatrix.pdf.
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CitrixXenApp Whileitisfocusedonapplicationvirtualizationandstreaming,CitrixXenAppblursthe linebetweenapplicationandpresentationvirtualizationbecauseitstemsfromCitrix’s formerPresentationServer.InordertosupportAppV,Citrixaddedsignificantfeatures tothePresentationServerengine.TheresultantAppVengine,XenApp,isavailablein threeeditions(seeTable12-3).Eacheditionbuildsontheothertoprovideacompleteset offeatures.XenApp,likeXenServer,isalsointegratedintotheXenDesktopoffering. NOTE For more information on XenApp, see www.citrix.com/English/ps2/products/product .asp?contentID=186.TotestdriveXenApp,downloadtheXenAppvirtualapplianceatwww.mycitrix .com.Youmustregisterfirst.
InstallFreeBridge InstallFree Bridge operates on the same principle as the InstallFree Desktop and uses thelocalPCresourcestorunapplications.Applicationsarealsooptimizedforstreaming,thoughnostreamingengineisavailablewiththeproduct.Applicationsaresimply placedonafileshareforuserstoaccess.ApplicationaccessissupportedthroughActive Directoryintegration.
Feature
Advanced
Enterprise
Platinum
Server-sideapplicationvirtualization
X
X
X
Application-basedloadmanagement
X
X
X
SpeedScreenprogressivedisplay
X
X
X
Client-sideapplicationvirtualization
X
X
Applicationperformancemonitoring
X
X
Systemmonitoringandanalysis
X
X
Applicationperformancemonitoring
X
UniversalSecureSocketsLayer(SSL)virtual privatenetwork(VPN)withSmartAccess
X
Single-sign-on
X
Applicationpasswordpolicycontrol
X
SmartAuditorsessionrecording
X
Wideareanetwork(WAN)optimization
X
EasyCallclick-to-calltechnology
X
Table12-3. TheDifferentXenAppEditionFeatureSets
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InstallFree requires an agent, but its agent is also virtualized and will run on any Windowsplatformusingstandarduseraccessrights.ThismeansthatInstallFreeAppV applicationsarecompletelytransportable.Justlaunchtheagentonanymachineandyou canrunanyvirtualizedapplication. Inaddition,theagentisthetoolthatrunstheInstallFreepackagingprocess.Because of this, you can package any application on any workstation without impacting the workstationandallthroughstandarduserrights. Inaddition,InstallFreehasabuilt-inmechanismforapplicationintegration.Toget two virtualized applications to work together, simply place them in the same folder. Whentheyarelaunched,eachapplicationwillautomaticallybeawareoftheother.This makesInstallFreeapowerfulAppVoffering.
MicrosoftApplicationVirtualization MicrosoftenteredtheAppVfraywhentheyacquiredSoftGrid.Theylatertookthetime torewritetheSoftGridcodetoreleaseApplicationVirtualization.MSApp-Vprovides three different deployment scenarios. You can deploy it through the System Center Application Virtualization Management Server to provide a complete set of features forAppVandstreaming.ThissolutionrequiresActiveDirectory(AD)andSQLServer tooperate.Youcanalsousealighter-weightSystemCenterApplicationVirtualization StreamingServer,whichdoesnotrequireADintegrationbutstillprovidesAppVand streaming capabilities. Smaller shops can deploy the stand-alone version of Microsoft ApplicationVirtualization.ThisprovidesAppVfeatures,butnostreaming. ApplicationVirtualizationisonlyavailablein32-bitclientversions,butMicrosoftis workingona64-bitversion.MSApp-Vworkswithbothdesktopandserver-basedor TerminalServicesapplications.ItisavailableonlythroughtheMicrosoftDesktopOptimizationPack(MDOP)forSoftwareAssuranceandisnotavailabletoclientswhodonot ownSoftwareAssurance. MS App-V includes the ability to support dynamic virtualization, which lets you packagemiddlewareapplicationsinsuchawaythattheyareavailabletomultiplevirtualizedapplicationpackages.Forexample,onesinglevirtualized.NETFrameworkpackagecansupportmultiple.NETapplicationsoncetheyarevirtualized.
SymantecSVSPro SoftwareVirtualizationSolutionwasthefirsttomarketwithanAppVfeaturesetwhenit wasownedbyAltiris.Later,whenSymantecacquiredAltiris,italsoacquiredAppStream andcombinedthetwofeaturesetstocreateSVSPro.SVSusesafilterdrivertovirtualize packages.Packagesarecreatedasarchives(.vsa)andthencompressedintodeliverable unitsusingacommoncompressionformat,suchasWinZip.Forthisreason,virtualpackages(.vsp)areviewablethroughtheWinZiputility.VSPsaredeployedtoendpointsand, oncedeployed,canbeactivatedordeactivated.Ifissuesarise,VSPscanberesettotheir originalstate,resettingtheapplicationsothatitrunsproperly.
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ThroughtheAppStreamcomponent,SVSProcansupporttheutmostinstreaming.In fact,thiscomponentoffersthebeststreamingfeaturesetofanyAppVtool.AppStream canevenstreamvirtualizeddesktopsifrequired.Andbecauseitsupportsallthreestreaming block types—startup, predictive, and on demand—AppStream can ensure that all systemsarepopulatedaccordingtothepoliciesyouset.Thisprovidestheverybestin userexperience. BecauseofthepowerfulfeaturesetincludedintheAltirisproductline,integrating SVSProwiththeAltirisESDsolutioncancreateacomprehensivemanagementsetfor anydistributeddesktopenvironment.
VMwareThinApp VMwaresignificantlyenhancedThinApponcetheyacquireditfromThinStallinlate 2007.Itsclaimtofameistheabilitytorunwithoutanagentbecausetheruntimeagent is included within the package itself. This makes applications completely transportable;however,thisrequiresyoutoimplementspecialprocedurestoprotectapplications fromtheft. ThinAppapplicationsrunonboth32-bitand64-bitversionsofWindows.ThinApp doesnotincludeadistributionmechanism,butThinAppapplicationsareoptimizedfor streamingwhentheyarebuilt.Thismeansorganizationsmustrelyontraditionaldeploymenttools,suchasESDsystemsorActiveDirectorydeployment.Deploymentsystems canalsobeassimpleasafileshareoradeploymentwebpage. Toupdateanapplication,allyouneedtodoisreplacetheoriginalapplication,whereveritmaysit.ThinAppincludesafeaturecalledAppSync.AppSyncwillautomatically updatedeployedapplicationsontargetworkstations.Inordertodoso,youmustadd theAppSyncWebsiteintheapplication’s.inifile.Also,.inifilesmustbenamedexactly thesameforeachversionoftheapplication;otherwise,theapplicationwillnotbeupdated.ThisprocedureisundocumentedintheThinAppdocumentation.Forexample, inordertoupdateWinZip10.0to12.2,youwouldensurethattheWinZip10.0.inifile pointedtotheappropriatewebpage.Then,whenyoucreatetheWinZip12.2package, younameits.inifileexactlythesameastheoneyouusedforversion10.0.Theapplicationwillautomaticallyupdatethenexttimetheuserlaunchesit. ThinApp also includesApplication Links, which link virtualized applications together.Forexample,youcanvirtualizeMicrosoftOfficeandAdobeAcrobatseparately, butstillgetthemtointegratewitheachotheroncevirtualized.ThinAppapplications workonanyversionofWindows,fromWindowsNTtoWindowsVista. NOTE Ifyoumakeapplicationsavailableonafileshare,youcanstillcontrolwhoseeswhatbyusing Access-Based Enumeration (ABE) inWindows. ABE will only display the files users have access to. Control access rights through Access Control Lists linked to AD security groups, and you will getasimilareffecttostreaming.LearnmoreaboutABEatwww.microsoft.com/windowsserver2003/ techinfo/overview/abe.mspx.
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MajorVendorPositioning Asyoucansee,vendorstakedifferentapproachestoAppV,buttheresultisextremely similar.However,eachvendorhassomethingtooffer.
▼ M icrosoftoffersApplicationVirtualizationthroughMicrosoftDesktop OptimizationPack(MDOP),whichlimitsitsavailability.Becauseofthis,you mayhavetochooseanothersolutionifyoudonothaveSoftwareAssurance, evenifyouhaveanall-Microsoftshop.
■ C itrixoffersXenApp,whichisanupdateofPresentationServerandcombines thebestofAppVwithpresentationvirtualization(PresentV).
■ V MwareThinstallandInstallFreeBridgearebothagentless,whichmakes applicationstransportable,butpresentslicensingchallenges.
▲ S ymantecleadsthepackwithSVSProbecauseofitscomprehensivestreaming features.
Considerthispositioningandevaluateeachfeaturesetbeforeyoumakeadecisionon whichplatformtoselect.
UsetheAppVDecisionProcess Liketheothertwomainstreamvirtualizationprocesses,makingadecisionforAppVis basedontheactualbusinessneedyouface(seeFigure12-1). However,inthiscase,thedecisionaddressestheneedsofmobilePCs.Ifacomplete desktopisrequired,optforasecurevirtualmachine;ifyouonlyneedtoaccessapplications,virtualizethem.DesktopPCsarenotincludedinthisdecisiontreebecauseall applicationsshouldbevirtualizedwithintheorganization.
Figure12-1. TheAppVdecisionprocess
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KEYPOINTSONAPPV Organizationseverywherespendinordinateamountsofresourcesmanagingapplicationinstallationpackagesandmakingsuretheseapplicationsalwaysworkintheirnetwork.What’sworse,applicationpackagingorrepackagingisoneofthebiggestbarriers toOSmigrationsbecauseorganizationsdonotwanttofacemassiveapplicationpreparationefforts. Toreducetheapplicationmanagementeffort,mostorganizationshavedesignedsystemimagesthatincludeentireapplicationsets.Theseorganizationsmanageanywhere fromtenstohundredsofsystemimages,updatingeachandeveryoneonaregularbasis. Whilethismakesitsimpletoreimageasystem,itiscumbersome,time-consuming,and requiresalotofadministrativeoverheadjusttomakeitwork. Nowyoucanhaveoneortwosinglesystemimages,sincealltheimagerequiresis thecoreOSandbaseutilities.Everythingelseisstreamedfromcentrallocations.Infact, youcanreimageasystemandhavetheenduserupandrunninginminutesoncethe systemisrebooted,becausestreamingonlysendsthebitstheuserneedsatanyonetime. Isn’tthisabetterdesktopmanagementmodel? Considerthefollowingandthendecideifyou’rereadytoreapthebenefitsofAppV streaming:
▼ V irtualizeapplicationswhereverpossibletodealwithapplicationconflicts onceandforall.Perform“spot”virtualizations,repackagingthemost problematicapplicationsyouowntoreapimmediatebenefitsfromapplication virtualization.VirtualizingapplicationswillalsorenderthemOS-versionindependentandletthemrunonanyOS.Thiswillremoveoneofthemost significantbarrierstoOSmigrations.
■ B ystreamingapplications,yousimplifyapplicationaccessandreducethe strainapplicationdistributionhasonyournetwork.Take,forexample, MicrosoftOffice:Wheninstalled,youmustsendhundredsofmegabytesto endpoints,butwhenyoustreamit,youonlyneedtosend10to20percentof theentireapplicationsettoyourendpoints.Bitsareonlysentwhenusersneed them,notinonemassiveunicastdistribution.
■ W ithapplicationvirtualization,youcannowconcentrateonasimplerway tobuildPCs.Createacoreimagewithbaseutilitiesandupdates.Ensure yourSVSProagentsareincludedinthisimage.Applicationsareassigned throughthestreamingengine,anduserdataandconfigurationsettingsare protectedthroughbuilt-inWindowsfeaturescombiningtheroamingprofile withfolderredirection.
■ W ithAppV,youcannowbuildonesinglereferencecomputerandalwayskeep it“clean”asapplicationsarecapturedandpreparedforstreaming.Sincefew applicationsarehardware-dependent,youcanevenrelyonavirtualmachine forthissystem.
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▲ C ompleteendpointmanagementmeansusingpointtechnologieswherethey fitbest.RelyonyourESDsystemtomanagethecoreOS,itsupdates,andthe baseutilitiesitincludes.RelyonAppVtoprotectapplicationsandpackage themonlyonceformultipletargetoperatingsystems.Relyonstreamingto provisionend-userapplications.Relyonyourdirectoryservicetomanage applicationgroupingsandend-userdata.Usetheseintegratedtechnologies toputanendonceandforalltotheapplicationmanagementnightmareand movetoa21st-centurydynamicdatacenter. Toimplementthisstrategy,relyontheTenCommandmentsofAppV:
1. Learnhowapplicationvirtualizationcanrevolutionizetheapplicationlifecycle.
2. Determinewhichproductbestfitsyourneeds.
3. Experimentwiththetooltounderstanditsinsandouts.
4. Categorizeyourapplicationsanduseapplicationsponsors.
5. Rationalizeallapplications.
6. Useastandardsystemconstructionmodelandastandardsystemstack.
7. Movetotheapplicationvirtualizationmodel.
8. Rememberthatpackagingbestpracticesstillapply.
9. Relyonapplicationstreamingfordelivery.
10. Learntomanagethelocalcache.
With these commandments in mind, look to a completely new application life cycle (seeFigure12-2),onethatreplacesthetraditionalapplicationmanagementapproaches.
Figure12-2. TheAppVlifecycle
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Inthenewlifecycle,youbeginbycapturinganapplication’srunningstateoncethe applicationhasbeenapprovedforintegrationintoyourapplicationportfolio.Then,you placeitintherepositoryandconfiguretheADgroupsandthecachingmodefortheapplication.Thisismuchsimplerthantraditionaldeployments.Theshortcuticonappears onusers’desktopswhentheylogin.Theapplicationisstreamedwhenactivated. Ifupdatesarerequired,applythemtothesoftwarerepository.Thenexttimetheapplicationislaunched,itisautomaticallyupdatedinthelocalcache.Whenitistimeto retiretheapplication,simplywipethelocalcacheandremoveitfromtherepository.This isapowerfulnewapplicationmanagementmodel.
INTEGRATEAPPLICATION,PROFILE, ANDDESKTOPVIRTUALIZATION Desktop virtualization offers the promise of centralized simplicity.Application virtualizationoffersthepromiseofapplicationsondemand.Profilevirtualizationoffersthe promiseofdataprotectionatalltimes.Combiningallthreeletsyoucreateacompletely newapproachtodesktopmanagement.Allthreecannowapplythroughoutthesystem constructionmodelandcontinuetoprotectitatalltimes.Infact,thisallowsyoutoconcentrateonthekeycomponentsofanyendpointandprotectthemasfollows:
▼ U sestandardsystemconstructionpracticestobuildthecoreOS.Relyon modelssuchasthePASSsystemkerneltodoso.
■ I nstallcoreutilitiesintothesystem—forexample,theagentsrequiredtorun thesoftwarecomponents,includingbothAppVandstreaming,aswellas protectionmechanisms,suchasantivirusandantimalware.
■ T ransformthecoreOSintoanimagetobedeployedtoallsystemsordeployed asaread-onlydesktopvirtualizationimage.
■ F romthatpointon,relyontraditionalESDtechnologiestomanageinstalled utilitiesandupdatethemasrequired,aswellastomanagecoreOSupdates.
■ P ackageallotherapplicationsasvirtualapplicationsandpreparethem forstreaming.
■ Depositallpackagesintothestreamingrepository.
■ S treamapplicationsglobally,eitheringroupsoronanadhocbasis,andmake themavailableatuserlogin.
■ U sethestreamingsystemtoupdateallstreamedapplicationsandtomanage applicationcachingparameters.
■ Usethestreamingsystemtomanageandharvestallapplicationlicenses.
▲ P rotectalluserdatathroughWindows’built-inuserpersonalityprotection capabilities,suchasroamingprofilesandfolderredirection,whichcanalso cacheuserdatalocallyinmuchthesamewayasthestreamingsystem.
Thisstrategygreatlysimplifiesthedesktopmanagementmodel.
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AssignApplicationsonDemand Whenyouworkwithdistributedsystems,youneedtomanagecomponentsatseveral differentlevels.First,youneedtomanageandupdatetheOSitself.Then,youneedto manageandupdateanycoreutilitiesordriversthathavebeendeployedinsupportof thephysicaltechnologiesyourorganizationhasselected.ThesetwolevelsofmanagementareoftenbestcontrolledbyESDsystemssincethesesystemsaredesignedtooffer supportforphysicaldevicecontrolandreimaging.ESDsystemsarealsobestsuited to the management of the agents you need to deploy for bothAppV and streaming management. Inaddition,theAppVandstreamingdatacenterwillsupportnewdesktopmanagementmodels.
▼ I nanAppVandstreamingdatacenter,thereislittleornoneedforpresentation virtualizationortheoperationofapplicationsoncentralizedserversthatshare accesstotheapplicationformultipleusers.TechnologiessuchasWindows TerminalServicesrequiretheclienttobephysicallyconnectedtooperate. Inaddition,theyrequiremassiveserversthatincludemultipleprocessors andheapsofmemorytosupportapplicationsharing.Withastreaming system,younolongerneedthisapplicationmanagementmodelsince streamedapplicationsarecachedlocallyandremainavailablewhenusersare disconnected.Inaddition,thestreamingserverisnothingbutaglorifiedfileor webserver,requiringfewerresourcesthanTerminalServicesservers.
■ B yvirtualizingdesktopsaswellasapplications,youcangainthebestofall worlds.AdesktopthatreliesonAppV,streaming,andauserinformation protectionstrategybecomesentirelyvolatile.Thismeansthatyoudonot needtoassignspecificdesktopstoendusers.Eachtimeauserconnectstoa virtualdesktop,itisbuilttosuiton-the-flybygeneratingthestandarddesktop, assigningtheuser’sapplicationsasrequired,anddeployingtheuser’sdataas needed.Sincethevirtualdesktopimage,thevirtualizedapplications,andthe end-userdataareallcentralizedonastorageareanetwork(SAN)back-end, systemconstructionisextremelyfast—nonetworktransmissionsarerequired, andalldataislocatedonthesamedisksets.
▲ F orendusersthatrequirehighgraphicscapabilities,youcanrelyon centralizedbladePCs—physicalsystemsthatarelocatedinthedatacenter andassignedtospecificusers.BladePCsincludehardwareaccelerationfor graphics,providingtheverybestcentralizeddesktopexperience.Onceagain, sincealldataandapplicationsarecentralized,accesstothesesystemsis extremelyfastandprovidestheverybestexperienceforgraphics-intensive users,suchasengineersorgraphicartists.
EachmodelprovidesafastandefficientwaytosupportbothdistributedandcentralizedPCs.
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UseaVolatileDesktopVM Thenextlevelistheproductivityapplicationlayer.Thislevelincludesandaddressesall ofthevirtualizedandstreamedapplicationsthatyoumanageandprovidetoyourusers, bothinternallyandexternally.Thefinallevelisthedatalevelandisdesignedtoprotect end-userdataandconfigurationoptionsatalltimes.Designingyourdistributedsystems managementinfrastructuresinthismannerletsyoucreateamoderndatacenterthatwill goalongwaytowardsreducingtraditionalsystemsmanagementheadaches. Thissimpleprocessgivesyoutheabilitytomanageallofyoursystemsandprovides youwithaneffectivemanagementmodel.Infact,allofyourendpointsaretransformed intoasortof“bull’seyetarget”thatismadeofthreekeylayers(seeFigure12-3).
▼ ThefirstlayerconsistsoftheOSitself.
■ T hesecondlayeristheapplicationcachinglayer,whereallvirtualized applicationsreside.
▲ Thethirdlayeristheuserdataandconfigurationlayer.
Allthreelayersarecompletelyprotectedatalltimes.ForITadministrators,thismeans that you can reimage any PC at any time with little or no consequence. For users, it meansthattheycanrelyonanyPCintheorganization—physicalorvirtual—towork withboththeirowndataandtheirownapplications. Thisnewconstructionmodelcanbeappliedtobothphysicalcomputerinstancesand virtualdesktops,lettingyourelyonanew“volatile”systemconstructionstrategy.Butto doso,youneedtoputnewelementsinplaceinyourdatacenter.
Figure12-3. Thenew“bull’seye”endpointsystemstack
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VirtualizeUserProfiles WhilemanyAppVvendorsaretryingtoputtogetherspecialfeaturesthatwillprotect userdataatalltimes,youcanbegintodothisimmediatelythroughthebuilt-infeatures ofWindows.UserdataisstoredwithintheuserprofileinWindows.Thisprofilemakes upthepersonalityofeachuser’senvironment. Personality protection is probably the most important aspect of operating system management;not,ofcourse,fromthetechnician’spointofview,butrather,fromtheend user’spointofview.Afterall,whilewe,asITprofessionals,viewacomputerasasystem weneedtobuildandmaintain;endusersviewitasanecessaryeviltheyneedtowork withtoperformtheirjobfunctions.Andpersonalities—thecollectionofdata,favorites, desktopsettings,applicationcustomizations,andmore—arethemostimportantaspect ofthissystemforthem. That’s because users perceive their computer’s personality as part of their workspace,andmanyofthemwillspendconsiderabletimeoptimizingitfortheworkthey do.Formanyusers,losingprintersettings,e-mailconfigurations,MicrosoftWordtemplates,oreventheplacementofshortcutsontheirdesktopcancompromisetheircomfortlevelandeffectivenesswithanysystem.Thisdisorientationdecreasesproductivity andincreasesthehelpdeskworkloadbecauseitleadstounnecessaryend-usersupport callsandtraining. Therefore,preservingthepersonalcomputingenvironmentofeachuserisacritical stepinmitigatingtheproductivityimpactofanyOSmanagementstrategy.
DefineYourPersonalityProtectionPolicy Inordertodefineyourprotectionpolicy,youfirstneedtounderstandpersonalitiesor profiles and how they work. A profile is generated the first time a user logs on to a system.Basically,thefirsttimetheuserlogson,thecontentsofthedefaultuserprofile arecopiedandpersonalizedfortheuser.Thesystemautomaticallyresetsthesecurity parametersofthesecontentssothattheuserhasexclusiveaccesstothem.Thisisone reasonwhyitissoimportanttoproperlymanagethecontentsofthedefaultuserprofile when you work with different operating systems. By creating one single default user view,youstandardizehowendusersaccessandinteractwiththecomputersystemsyou deploytothem.Ofcourse,theywillmakethisprofileevolve,butyoucanatleastensure thatcertainkeyelementsremaincommoninallprofiles. Userscanlogonthroughadomain,relyingonanActiveDirectory(AD)authentication,orthroughthelocalsystem,relyingonthelocalsecurityaccountsmanager(SAM) databasethatcanbefoundoneveryWindowssystem.Eachfirst-timelogonwillcreate aprofile.Thismeansthattechnicianswhologontoasystemforrepairpurposeswill automaticallygenerateaprofile,aswillanyotheruserloggingonforotherpurposes. Mostlocallogonsarevolatilebecausefeworganizationsruntheirnetworkwithout acentralauthenticationdatabasesuchasADprovides.Thismeansthatinmostcases, you can discard any local profiles from your protection strategy—that is, unless you havecustomsystemsthatoperateinaworkgrouponly.Manyorganizationsusesuch systems to monitor and maintain systems connected to a demilitarized zone (DMZ), suchasthosefoundinaperimeternetwork.Youcanevaluatetheopportunitytoprotect such local profiles versus having administrators and technicians re-create them when
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thesemachinesareupgraded.Ifyourdefaultuserprofileisproperlycreated,thevalue ofprotectinganylocalprofilewillbeminimal. Therefore,yourprotectionpolicyshouldconcentrateonprofilesthataregenerated throughdomainlogins.IfyournetworkoffersasinglePCtoaprincipaluser,you’llhave itrelativelyeasy,sinceallyouwillneedtodoisidentifytheprincipaluser’sprofileona system,protectit,anddiscardallotherprofiles.Ifyournetworkusessharedcomputers, itwillbeslightlymoredifficult.Domainloginprofilescanalsobeprotectedbyother means,suchasroamingprofiles—profilesthatarestoredonthenetworkanddownloadedtoeachPCastheuserlogson—orfolderredirectionpolicies—GroupPolicyobjects (GPOs)thatmovethecontentsoflocalfoldersfoundintheprofiletonetworklocations. Youranalysiswillneedtotakethesefactorsintoaccountifyouwantaprotectionpolicy thatwillmeettheneedsofeveryuserinyournetwork. Someorganizations,especiallythosethatmustoperate24/7,willalsohavegeneric accountsintheirnetwork.Genericaccountsaresharedaccountsthatallowoperatorsto shareamachinewithoutneedingtologonoroffattheendoftheirshift.Therearetwo types of generic production accounts. The first deals with 24/7 operations and is requiredtorunamachinewithouttheneedtologonoroff.Operatorssharethepassword tothisaccountandcanthuschangeshiftswithoutclosingthesession. The second type is for environments that have a high personnel turnover.A good exampleofthisisonnavalvessels.Sinceofficersandstaffchangealmosteverytimethe shipdocksandcrewsarerotated,someorganizationschoosetousegenericrole-basedaccountsinsteadofnamedaccounts.Forexample,afirstofficerwouldusetheFirstOfficer accountinsteadofonenamedafterhim-orherself.Inthissituation,thepasswordmayor maynotbeshared.Itdependsontheamountofefforttheadministrativestaffiswilling toundertakeateachcrewchange.Theycaneitherresetthepasswordsofeachgenericaccountornot,astheywant.Obviously,apolicythatwouldrequireeithernamedaccounts thatcouldberenamedeachtimeacrewmemberchanges,orpasswordchangesateach crewchange,wouldbemuchmoresecurethanonewherepasswordsareshared.
ChoosingtheProfilestoProtect Becauseofthevarioustypesofprofilesinanetwork,youneedtohavethemeanstodeterminewhichprofilestoprotect.Thebestwaytodothisistouseaflowchartthatidentifieswhichprofilestoprotectandunderwhichcircumstances(seeFigure12-4).Keepin mindthereasonswhyyouwouldorwouldnotprotectagivenpersonality. Yourdecisionflowshouldincludethefollowingguidelines:
▼ L ocalprofilesareonlyprotectediftheyaresituatedonspecialmachinesthat arenotpartofthedomainandcannotbereplacedbyacustomdefaultprofile.
■ D omainprofilesareprotectediftheyhavebeenusedrecentlyandon aconstantbasis.
■ Onlyprofileswithactualcontentareprotected(basedonprofilesize).
■ Onlyactiveprofilesareprotected.
▲ I fyourmachineshaveprincipalusers,theirdomainprofilesareprotectedat alltimes.
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Figure12-4. Usingadecisioncharttodeterminethepersonalityprotectionpolicy
Thereare,ofcourse,otherconsiderations,butthesedecisionsshouldformthemaincrux ofyourpersonalityprotectionpolicy.
CreatethePersonalityProtectionStrategy Nowthatyouknowwhichprofilestoprotect—mostlydomainprofiles—youcanmove tothecreationofyourprofileprotectionstrategy.Microsofthasputinalotofeffortto makepersonalityprotectionaneverydayprocess.That’sright—theentireUserfolder structure has been designed to provide support for one thing: folder redirection and generalprofileprotection. FolderredirectionisanaspectofGroupPolicythatwillautomaticallyredirectuser folderstocentrallocations.Whencoupledwithofflinefoldercaching,folderredirection canprovidethebestofallworldsforusers,whethertheyareroamingornot.Foldersare locatedonnetworkshareswheretheycanbebackedupandmadeavailableatalltimes.
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Their contents are cached locally, so even mobile users have access to their data even when disconnected. If any changes are made locally, they are automatically synchronizedthenexttimethenetworkconnectionisavailable.Thismeansthatbothconnected anddisconnectedusershaveconstantaccesstotheirdata. You can combine folder redirection with roaming user profiles to gain the best of both worlds. Volatile items, such the NTUser.dat file—the file that contains all of the in-memory contents of a profile—are not contained in folder redirection. This means thatrelyingonfolderredirectionalonemayprovidealess-than-completeexperiencefor users.Inaddition,relyingonroamingprofilesalonelimitstheexperiencebecausedatais notavailableinrealtimeasitiswithfolderredirection.Profilesaremonolithicfilesthat cantakealongtimetobecomeavailableduringtheloginprocess. Bycombiningboth,youwillhavefolderredirectionmanagethedatawithintheprofileandmakeitavailableasfastaspossible,aswellashavingroamingprofilesmanage therest.Inthisscenario,thedatacontainedwithinfolderredirectionisexcludedfromthe roamingprofile.Theresultisaprofilethatloadsfastbecauseitscontentsaresmall,and usersthathaveaccesstodataatalltimesthroughfolderredirection.AnadditionaladvantageisthatcombiningthetwoletsyousupportroamingusersineitherWindowsXPor Vista,orevenbothifyouneedit. Butformany,thismeansrethinkinghowtheyprovideprotectionforuserdata.Many organizationshavereliedontheuserhomedirectoryand/orroamingprofilestoprovide thistypeofprotectioninthepast. Thehomedirectorywasoriginallydesignedtoprovideasimplewaytomapuser sharesonanetwork.InWindowsNT,2000,andWindowsServer2003,usingthe%username%variableinatemplateaccountautomaticallygeneratesthehomedirectoryfolder andappliestheappropriatesecuritysettings,givingtheusercompleteownershipover thefolderwhenyoucreateanewaccount.Whentheuserlogson,thisfolderisautomaticallymappedtotheH:driveoranyotherletteryouassign.Buttoday,youshouldn’tbe relyingonmappeddrivesanymore.YoushouldberelyingontheDistributedFileSystem(DFS),especiallyDFSnamespaces. DFSnamespacesuseuniversalnamingconvention(UNC)sharestomapresources forusers.Butinsteadofusingthe\\servername\sharenameapproach,DFSnamespaces use\\domainname\sharenameandeachnamespaceismappedtoanappropriatetarget ineachsiteofyourorganization’snetwork.DFSreplicationkeepsthecontentofthese targetsharessynchronizedovertheWAN. NOTE Find more information on DFS at www.microsoft.com/windowsserver2003/technologies/ storage/dfs/default.mspx. SinceWindows2000,MicrosofthasfocusedontheuseoftheMyDocumentsfolder asthehomeofalluserdocuments.ThisfolderispartofthesecuritystrategyforallWindowseditionsbeyondWindows2000,eventhoughithasbeenrenamedDocumentsin
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WindowsVista.Thisfolderisstoredwithinauser’sprofileandisautomaticallyprotected fromallotherusers(except,ofcourse,administratorswhenappropriateaccessrightsare assigned).
FolderRedirectioninWindowsXP InWindowsXP,folderredirectioncanmanagefourcriticalfoldersandassignnetwork sharesforeach.Theseinclude:
▼ ApplicationData,whichstoresallapplication-specificsettings.
■ Desktop,whichincludeseverythingusersstoreonthedesktop.
■ M yDocuments,whichistheuser’sdatastoragefolder.StoringtheMyPictures subfolderonthenetworkisoptional.
▲ StartMenu,whichincludesallofauser’spersonalshortcuts.
WhenredirectionisactivatedthroughGroupPolicy,thesystemcreatesaspecialfolder basedontheuser’sname(justlikeintheolderhomedirectoryprocess)andappliesthe appropriatesecuritysettings.Eachofthefoldersmentionediscreatedwithintheuser’s parentfolder.DatainthesefoldersisredirectedfromthedesktopPCtotheappropriate networkfoldersandbecauseofthis,canalsobemadeavailableofflineforclientssuchas mobileusers.Whenusersaredisconnected,dataisstoredlocally;whentheyreconnect, itisautomaticallysynchronizedwiththenetworkfolders. Buttheuserprofileincludesmuchmorethanthesefourmainfolders.Infact,highly volatile information, such as Local Data and Favorites, is not protected. Because of this,youcan’trelyonWindowsXP’sfolderredirectionalonetoproperlyprotectasystem’spersonality. NOTE For users that roam to remote offices, you can combine folder redirection with DFS namespaces and replicate the contents of their folders to DFS target shares in remote locations. MakesureyouarerunningWindowsServer2003R2orlatertotakeadvantageofthenewdelta compressionreplicationengineinDFSreplication.
FolderRedirectioninWindowsVista AllofthischangeswithWindowsVistabecauseitfinallyprovidesamechanismfortrue folderredirectionandpersonalityprotection.Thisisevidencedinthesettingsavailable forfolderredirectioninaVistaGroupPolicyobject(GPO).Asyoucansee,itincludes redirectionformuchmorethanXPeverdid(seeFigure12-5). Thismakesfolderredirectionanexcellentchoiceforlong-termpersonalityprotectionsinceitiscompletelytransparenttotheuser.Whiletheythinktheyareusingthe DocumentsfolderlocatedontheirPC,theyareactuallyusingafolderthatislocatedon thenetwork.Thisway,youcanensurethatalluserdataisprotectedatalltimes.
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Figure12-5. Vista’sFolderRedirectionGPO
Usingafolderredirectionstrategyratherthanahomedirectorysimplifiestheuser data management process and lets you take advantage of the advanced features of a Windowsnetwork.Forexample,eventhoughdataisstoredonthenetwork,itwillbe cachedlocallythroughofflinefiles.Redirectedfoldersareautomaticallycachedthrough client-side caching when they are activated through a GPO. Data in these folders can alsobeencryptedthroughtheEncryptedFileSystem(EFS).Infact,allofflinefilescan beencrypted. Vista lets you redirect ten different folders. When you combine the redirection of thesefolderswithroamingprofiles,youofferthebestroamingexperiencetouserswith alowerimpactonnetworktrafficthanwithroamingprofilesalone(seeTable12-4). VistafolderredirectionpoliciesincludemoresettingsthanforXP.Forexample,you canautomaticallydeleteolderorunuseduserprofilesfromyourPCs(seeFigure12-6).
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Comments
AppData (Roaming)
Thisfoldercontainsallroamingapplicationdata. RedirectingthisfolderwillalsosupportWindowsXPclients withlimitations.
Desktop
Usersshouldnotstoredataoranyotheritemsontheirdesktops; theyshouldrelyontheQuickLaunchmenuinstead.This reducesthesizeofthefoldertoredirect.Includethisinyour communicationstothem. RedirectingthisfolderwillalsosupportWindowsXPclients.
StartMenu
ThecontentsoftheStartmenuareredirected.Ifyouuse applicationvirtualization,userswillalwayshaveaccesstotheir applicationsonanyPC,eveniftheyarenotinstalled. RedirectingthisfolderwillalsosupportWindowsXPclients.
Documents
Thiscontainsalluserdata.Makesureyourstoragepolicyand quotassupporttoday’slargefilesizesandgiveusersenough roomtobreathe. RedirectingthisfolderwillalsosupportWindowsXPclients. Applyingthispolicytopre-Vistaoperatingsystemswill automaticallyconfigurePictures,Music,andVideostofollow Documentseveniftheyarenotconfigured.
Pictures
Determineifyourorganizationwantstoprotectthisfolder.If youdo,usetheFollowTheDocumentsFolderoptionorrelyon thesettinginDocuments. RedirectingthisfolderwillalsosupportWindowsXPclients.
Music
Determineifyourorganizationwantstoprotectthisfolder.If youdo,usetheFollowTheDocumentsFolderoptionorrelyon thesettinginDocuments.Usingthisoptionwillalsosupport WindowsXPclients.
Videos
Determineifyourorganizationwantstoprotectthisfolder.If youdo,usetheFollowTheDocumentsFolderoptionorrelyon thesettinginDocuments.Usingthisoptionwillalsosupport WindowsXPclients.
Favorites
OnlyappliestoVista.
Contacts
OnlyappliestoVista.IfyouareusingMicrosoftOutlook,this Contactsfolderisnotnecessary.
Table12-4. RecommendedSettingsforCombiningVistaFolderRedirectionwithRoamingProfiles
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Folderto Redirect
Comments
Downloads
OnlyappliestoVista.Youwillneedtodetermineifyour organizationwantstoprotectdownloadsusersobtainfromthe Internet.
Links
OnlyappliestoVista.
Searches
OnlyappliestoVista.
Saved Games
OnlyappliestoVista.Thecontentsofthisfolderaresmalland applymostlytothegamesincludedinVista.Yourorganization willneedtodetermineifyouwanttospendnetworkbandwidth andstoragespaceonthiscontent.
Table12-4. RecommendedSettingsforCombiningVistaFolderRedirectionwithRoamingProfiles (continued)
Figure12-6. WindowsVistaletsyoucontrolthebehaviorofuserprofilesoneachPC.
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Inaddition,thesettingsyoucanuseforpersonalityprotectionaremuchmoregranularthaninanypreviousversionofWindows.Music,Pictures,andVideocanallbesetto automaticallyfollowthepolicyyousetfortheDocumentsfolder. YoucanalsousethesamepolicytomanagefolderredirectionforbothWindowsXP andWindowsVista(seeFigure12-7).Thisprovidespowerfulsystemmanagementcapabilitiesandletsyousetonesinglepolicyforbothoperatingsystems.
EnableFolderRedirectionwithRoamingProfiles Therearespecialconsiderationswhenenablingfolderredirection.First,youneedtoensurethateachuserisredirectedtotheappropriateserver.Itwouldn’tdotohaveauser inNewYorkredirectedtoaserverinLosAngeles.Todothis,youmustcreatespecial administrativegroupsthatcanbeusedtoregroupusersandensurethateachuserisassignedtotheappropriateserver;youmostlikelyalreadyhavesecuritygroupsyoucan useforthis.Youmustalsoensurethatofflinesettingsareappropriatelyconfiguredto guaranteethatusersareworkingwiththelatestversionoftheirofflinefiles.
Figure12-7. FolderredirectioninVistaoffersseveralmorechoicesthaninWindowsXP,butlets yousetonepolicyforbothVistaandXP.
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CAUTION Make sure you assign appropriate amounts of storage to each user for folder redirection.Thereisnopointinmakingthiseffortifyoulimitdiskspaceaccesstosomethingthatis unacceptable. Redirectingfoldersthroughusergroupingsis,infact,similartocreatingregional,or rather,geographicallybasedusergroups.Sinceeachserverisaphysicallocation,you willneedtocreateausergroupforeachone.Beginbyenumeratingthelocationofeach fileserverthatwillhostuserfoldersandthennameeachglobalgroupaccordingly.Once thegroupsarecreated,youcanbegintheredirectionprocess.Usinggroupsallowsyou tolimitthenumberofGPOsrequiredforthefolderredirectionimplementation. Usethefollowingproceduretoprepareyourfolderredirectionwitharoamingprofilesstrategy.MakesureyouarerunningWindowsServer2003ServicePack1(SP1),R2 orWindowsServer2008asyourserverOS.Also,makesureallGPOsettingsareprepared andmodifiedfromaVistaPCwithSP1togainaccesstothemostcompletesettings.
1. B eginbycreatingthesharesthatwillsupportredirectionandroaming.You willneedaminimumoftwoshares:onefortheuserprofiles(forexample, User_Profiles)andoneforfolderredirection(forexample,Folder_Redir).If youarealreadyusingXProamingprofiles,usethissharefortheprofiles.
2. B ecauseVistaandXPdonotdisplaymuchuserinformationduringlogonand logoff,youmightwanttochangethisdefaultbehavior.ApplyaGPOtoall PCsandselecttheAdministrativeTemplates|System|VerboseVsNormal StatusMessagesoptionunderComputerConfiguration|Policies.Thiswill letusersknowwhatishappeningduringlogon,anditmightalsobeusefulfor debuggingissues.
3. V erifythatroamingprofileshavebeensetupinuseraccountpropertiesinAD. IfyouusebothXPandVista,eachuserwillhavetwoprofiles—version1forXP andversion2forVista.Todifferentiatethem,Vistatacksonthe.v2extensionto theprofilefoldernames(forexample,JDoe.v2).
4. T oreducethecontentoftheroaminguserprofileandthereforelimitnetwork trafficandlogontimes,excludekeyfoldersfromtheroamingprofilecontents. UsetheAdministrativeTemplates|System|UserProfiles|Exclude DirectoriesInRoamingProfileoptionunderUserConfiguration|Policies.List eachofthetenfolderssupportedbyVista’sfolderredirection(seeTable12-4 forareminderofthefoldernames).TypethenameasitappearsinWindows Explorerandseparateeachnamewithasemicolon(;).
5. R elyonthesuggestionsinTable12-4tosetyourfolderredirectionpolicy.Use WindowsSettings|FolderRedirectionoptionsunderUserConfiguration| Policiestodothis.Changethepropertyofeachfolder.Redirectthemtoyour folderredirectionshare.Hereareacoupleofcaveats:
■ W henyousetthefolderpropertiesforfoldersthataresupportedbyboth WindowsXPandVista,usetheAlsoAllowRedirectionPolicyoptionunder theSettingstab(seeFigure12-8).
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Figure12-8. Vista’swarningmessagefortheDocumentsfolder
■ W henredirectingAppData(Roaming),youwillgetacompatibilitywarning message(seeFigure12-9).ThisisbecauseolderWindowsoperatingsystems donotsupportthefullfunctionalityofVistaintermsoffolderredirection.
■ W henredirectingtheDocumentsfolder,youwillalsogetawarningmessage. Inthiscase,ittellsyouthatbyselectingtosupportolderoperatingsystems,you automaticallychangethebehaviorofthePictures,Music,andVideofolders; theywillbeprotectedbydefaultandsettoFollowTheDocumentsFolder.If youdonotwanttoprotectthem,setthepolicyexplicitlyforeachfolder.
Testthestrategyinthelabbeforedeployingittoproduction.Tomakesureyouhaveit right,haveexpertuserssignoffonitthroughacceptancetestingtomakesuretheyare happywithitsoperation.
Figure12-9. Vista’scompatibilitywarningmessagefortheAppDatafolder
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FINALIZETHEPERSONALITYPROTECTIONSTRATEGY Takethetimetopreservewhatmakesyourusersfeelsuccessfulandcomfortableindoingtheirjobsanditwillpaydividends.Whenmappeddrivesarerestored,printersappearjustastheydidpreviouslyanddata,shortcuts,andfavoritesareexactlyastheuser leftthem;thefocusoftheusershiftstowardusingthesystemtoperformtheirtasks,not fixtheirprofile.Theywill,therefore,bemoreproductive. Ifyoutakethetimetoprepareaproperlong-termprotectionpolicythroughfolderredirectionandroamingprofiles,you’llbereadytoprovidefullsupportforthevolatilePC.
KEYPOINTSONTHEPERFECTDESKTOP KeepthefollowinginmindwhenyousetupyourvolatilePCstrategy:
▼ B uildthecoresystemimagetoincludeonlyabsolutelyrequiredcomponents, utilities,updates,anddrivers.
■ V irtualizeallapplicationsandprovidethemthroughastreamingengineto increasethespeedoftheiravailability.
▲ V irtualizeallprofilesandprotectthemoutsideofthePCimage.Makesure theprofilesareredirectedtolong-termsharedfilefolders.UseDFStosimplify sharedfolderaccess.
Thisway,allofyourcentralizeddesktopvirtualizationimagescanbecompletelyvolatile andbuilton-the-flyasuserslogin.Thiswillsaveinordinateamountsofdiskspaceand willworktocomplementthedelta-baseddifferentialVMfilescreatedbytechnologies suchasXenDesktoporVMwareView. Thisistheonlystrategytousewhenyouwanttomovetovirtualdesktopsandcreate adynamicdesktopdatacenterstrategy.
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S
ecurity is a pervasive issue because it involves almost everything within your network.Theobjectofsecurityistoprotectinformation.Determiningthevalueof theinformationyouneedtoprotectwillhelpyoudeterminewhichlevelofsecurity youneedtoapplytoit. Whileprotectingtraditionalnetworksisnothingnew,protectingvirtualinfrastructurespresentschallengesthatyoumayneverhavefacedbefore.First,youneedtounderstandwhichtypesofchallengeswillariseintheresourcepool,thegroupingofyour hostservers.Secondyouneedtolearnifunknownorunforeseenchallengeswillarise intheinfrastructureyoucreatetorunyourvirtualworkloads.Thisdivisionoftheinfrastructureintophysicalandvirtualmachinesdemandsnewapproachesandaserious reflectiononsecuritypractices. However,traditionalsecurityapproachesstillapplyevenifyouhavetwodifferentinfrastructurestoprotect.Toprotecteachoftheseinfrastructures,youmustputin placealayeredprotectionsystemthatwillprovidetheabilitytoperformthefollowingactivities:
▼ Identifypeopleastheyentereachinfrastructure.
■ I dentifyappropriateclearancelevelsforpeoplewhoworkwithineach environmentandprovidethemwithappropriateaccessrightsonceidentified.
■ I dentifythatthepersonmodifyingthedataisthepersonwhoisauthorizedto modifythedata(irrevocabilityornonrepudiation).
■ G uaranteetheconfidentialityofinformationonceitisstoredwithinyour infrastructures.
■ Guaranteetheavailabilityofinformationinyourinfrastructures.
■ Ensuretheintegrityofthedatastoredwithinyourinfrastructures.
■ Monitortheactivitieswithineachinfrastructure.
■ A uditsecurityeventswithinthenetworkandsecurelystorehistorical auditingdata.
▲ P utinplacetheappropriateadministrativeactivitiestoensurethatthenetwork issecureatalltimesandatalllevels.
Foreachoftheseactivities,therearevariousscopesofinteraction.
▼ Local Peopleinteractwithsystemsatthelocallevel;thesesystemsmustbe protected,whetherornottheyareattachedtoanetwork.
■ I ntranet Peopleinteractwithremotesystems.Thesesystemsmustalsobe protectedatalltimes,whethertheyarelocatedonthelocalareanetwork (LAN)orthewideareanetwork(WAN).
■ I nternet Systemsthataredeemedpublicmustalsobeprotectedfromattacks ofalltypes.Theseareinaworsesituationbecausetheyareexposedoutsidethe boundariesoftheinternalnetwork.
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▲ Extranet Thesesystemsareoftendeemedinternal,butareexposedtopartners, suppliers,and/orclients.ThemajordifferencebetweenextranetandInternet systemsisauthentication—whiletheremaybeidentificationonanInternet system,authenticationisalwaysrequiredtoaccessanextranetenvironment.
Whateveritsscope,securityisanactivity(likeallITactivities)thatreliesonthreekey elements:people,PCs,andprocesses.
▼ Peoplearetheexecutorsofthesecurityprocess.Theyarealsoitsmainusers.
■ P Csrepresenttechnology.Theyincludeaseriesoftoolsandcomponentsthat supportthesecurityprocess.
▲ Processesaremadeupofworkflowpatterns,procedures,andstandardsforthe applicationofsecurity.
The integration of these three elements will help you design a security policy that is applicabletoyourentireorganization.
THECASTLEDEFENSESYSTEM Thebestwaytodefineasecuritypolicyistouseamodel.Themodelwehavereliedon formorethanadecadeistheCastleDefenseSystem(CDS).Inmedievaltimes,people neededtoprotectthemselvesandtheirbelongingsthroughthedesignofadefensesystemthatwasprimarilybasedoncumulativebarrierstoentry,oraswewouldsaytoday, defenseindepth.Yourvirtualenvironmentshouldbeprotectedthesamewayasyou protectyourphysicalnetworkenvironment.Acastleisusedbecauseitisanillustration thatisfamiliartoalmosteveryone,fromuserstotechniciansaswellasmanagement. NOTE FormoreinformationontheCastleDefenseSystemandhowyouapplyittovirtualworkloads, seeMicrosoftWindowsServer2008:TheCompleteReferencebyRuestandRuest(McGraw-Hill,2008). AnITdefensesystemshouldbedesignedinthesamewayasaCDS.Justlikethe CDS,theITdefensesystemrequireslayersofprotection.Infact,fivelayersofprotection seemappropriate.Startingfromtheinside,you’llfind:
▼ Layer1:CriticalInformation Theheartofthesystemistheinformationyou seektoprotect.Thisistheinformationvault.
■ L ayer2:PhysicalProtection Securitymeasuresshouldalwaysbeginwith alevelofphysicalprotectionforinformationsystems.Thiscomparestothe castleitself.
■ L ayer3:OperatingSystemHardening Oncethephysicaldefenseshavebeen putinplace,youneedto“harden”eachcomputer’soperatingsysteminorder tolimitthepotentialattacksurfaceasmuchaspossible.Thisisthecourtyard.
■ L ayer4:InformationAccess Whenyougiveaccesstoyourdata,you’llneed toensurethateveryoneisauthenticated,authorized,andaudited.Theseare thecastlewallsandthedoorsyouopenwithinthem.
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▲ Layer5:ExternalAccess Thefinallayerofprotectiondealswiththeoutside world.Itincludestheperimeternetworkandallofitsdefenses.Itisyour castlemoat.
ThisistheCastleDefenseSystem(seeFigure13-1).Inordertobecomeacompletesecuritypolicy,itmustbesupplementedbytwoelements:peopleandprocesses.Thesetwo elementssurroundtheCDSandcompletethesecuritypolicypictureitrepresents.
Figure13-1. ThefivelayersoftheCastleDefenseSystem
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ResourcePoolsVersusVirtualServiceOfferings Thechallengeistoidentifyhowsecuritymustdifferwhenrunningvirtualinfrastructures.VirtualServiceOfferings(VSOs)willrunallofthenetworkedservicesyourend users interact with. Therefore, the traditional security measures you undertake when buildinganddesigningtheseservicesstillapply.Thefactthatusersinteractwithvirtual machinesinsteadofphysicalmachinesdoesnotchangetheneedfortightsecurityatall levelsinthisinfrastructure. Whatdoeschangeishowyousecureresourcepools.Bytheirverynature,resource poolsarenotdesignedtointeractwithusers.Theyarenothingmorethanhostservers thatrunavirtualizationengine.Becauseofthis,theywillbedealtwithbyadministrators andtechniciansonly.AnenduserrunningMicrosoftOutlookwillneverhaveanyinteractionwiththeresourcepoolitself.Instead,theenduserwillinteractwithanumberof differentvirtualmachinesrunningActiveDirectory,MicrosoftExchange,andperhapsa collaborationenginesuchasMicrosoftOfficeSharePointServer.Sincethesemachinesare allvirtual,thereisnodirectinteractionbetweenusersandhostservers(seeFigure13-2).
Figure13-2. UserinteractionswithresourcepoolsandVirtualServiceOfferings
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Becauseofthis,youshouldconsidercreatingsegregatedsecuritycontextsforboth theresourcepoolandtheVirtualServiceOfferings(seeFigure13-3).Bysegregatingsecuritycontexts,youareassuredthattherecanbenoseepagefromoneenvironmentto another.Forexample,ifyouusetwocompletelydifferentsecuritycontexts,anenduser fromtheVSOenvironmentwillnothaveanyaccesstotheresourcepool. Thesecuritycontextsegregationisoftenfacilitatedbytheverytechnologiesyou usetorunyournetworkservices.Forexample,manyorganizationsrelyonWindows toruntheiruserproductivityinfrastructurewithinthevirtualworkloads.Ifthisisthe caseforyouandyouhavedecidedtoworkwitheitherCitrixXenServerorVMware VirtualInfrastructure(ESXorESXiServer),thesegregationwilloccurnaturallysince
Figure13-3. SegregatedsecuritycontextsbetweenresourcepoolsandVirtualServiceOfferings
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bothhypervisorsrunonamodifiedLinuxinfrastructure.However,youwillneedto makesurethatyoudonotputinplaceanyofthetechnologiesthatsupporttheintegrationofsecuritycontextsbetweenWindowsandLinux.Forexample,youcouldcreate aKerberosrealmbetweenActiveDirectoryandaLinuxsecuritycontext.Thiswould letyouusesingle-sign-onbetweenthetwonetworks.Butsinceyouraimistoprotect the host servers from end-user access, you would consciously make sure that these technologiesarenotlinkedtogetherinthisway. If you use Linux to deliver your Virtual Service Offerings and you use either the CitrixortheVMwarehypervisor,you’llbeinasimilarsituationasifyouwereusing WindowsforVSOsandHyper-Vasthehypervisor.Inthiscase,bothenvironmentsuse the same technologies to provide security contexts. Because of this, you need to consciouslycreateseparatesecuritycontextstoprotecthostserveraccess.Forexample,in Windows,youwouldcreateanActiveDirectory(AD)forestforyourproductionusers andanotherforyourresourcepool.Thesetwoforestswouldnotbelinkedtogetherand wouldbekeptseparateatalltimes.Also,whileyourADforestforproductionwillmost likelyhaveacomplexorganizationalunit(OU)structure,theforestyoucreateforthe resourcepoolshouldreallybeautilityforestand,assuch,shouldrelyonthemostbasic ofOUstructures.
SecureResourcePools Becauseyouwillbeusingsegregatedsecuritycontexts,youneedtotakeatwo-pronged approach to the design of your CDS.As mentioned earlier, the CDS for VSOs should reallybesimilartothestandarddefensemechanismsthatyouhaveusedtodateand, therefore,doesnotneedtobecoveredinasmuchdepthhere. Instead,youneedtofocusoncreatingaCastleDefenseSystemfortheresourcepool itselfsincethisisanewactivityforyouandyourteam.Thispoolmustincludestrict protectionstrategiesbecauseitissoeasytowalkawaywithanentirevirtualmachine. AnyonewithaniPodandaccesstothevirtualmachines(VMs)caneasilycopythemand takethemaway. As such, the CDS for resource pools will require particular attention to the levels identifiedinTable13-1. ResourcepoolsareanewconceptinITand,therefore,needaparticularattention todetailwhenitcomestotheimplementationoftheirsecuritysettings.Youneedto makesureyouunderstandthescopeofprotectionyouneedtoapplytothisinfrastructure(seeFigure13-4).Thisscopewilladdressonlythehostserversinthedatacenter (blade or rack-mounted servers preferably), all-in-one box servers in remote offices, themachinesusedtocontrolthehostservers,andthemachinesusedasconsolesto accessthehostservermanagementinterfaces.Thelastsetofmachinescanbevirtual machines,runningmanagementserverVMsinredundantconfigurations,andusing virtualdesktopstiedtotheresourcepoolsecurityenvironmenttoconnecttothemanagementinterfaces.
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Layer
Contents
Contents
Layer1: Critical information
Datacategorization
Payspecialattentiontothefiles thatmakeupvirtualmachines, theirstoragecontainers,andhow peoplecanaccessthem,especially offlinecopies.
Application hardening
Securethedatabaseinstallations requiredtosupporttheserver virtualizationengineorhypervisor yourun.
Physicalenvironment
Makesuredatacentershavesufficient powerandcoolingresources.
Layer2: Physical protection
Remoteofficesshouldrelyonserverin-a-boxconcept. Physicalcontrols
Payspecialattentiontophysical accesstoservers. Allservers,especiallyremoteservers, shouldbeunderlockandkey.
Layer3:OS hardening
Communications
Makesureallresourcepool administratorsandtechnicians understandtheirresponsibilitiesin termsofsecuritypractices.
Surveillance
Ifpossiblehavesign-inandsignoutsheetsforadministratorsand techniciansphysicallyenteringthe datacenter.
Securityconfiguration Payspecialattentiontotheserver virtualizationengineinstallationon eachhostserveraccordingtothe manufacturer’sbestpractices. Filesystem
Securethesharedstoragefilesystem toprotectVSOs.
Printsystem
Notapplicablebecauseonly administratorshaveaccesstothis networkandtheycanprintfromtheir workstations.
Table13-1. ApplyingtheCDStoResourcePools
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Webserver
ImplementtightWebserversecurity ifyouneedtorelyonsoftware virtualizationenginessuchas MicrosoftVirtualServerorVMware Servertoaddlifeto32-bithardware.
Systemredundancy
RelyontheprinciplesinChapter15 toensurebusinesscontinuityof hostservers.
Useridentification
Createnamedaccountsforeach administratorortechnicianthathas accesstotheresourcepool.
Securitypolicies
Assignproperpoliciestothe resourcepool.
Resourceaccess
Onlyadministrativeaccountsare requiredinthisnetwork.Useaproper delegationofadministrationstrategy.
Accessauditing/ monitoring
Turnonauditingandloggingtotrack allchanges.
Digitalrights management
Notapplicablesincethis infrastructureisnotusedto producedocumentation.
Layer5: Perimeternetworks Externalaccess
Thereisnoperimeternetworkin theresourcepool,butyoushould stillproperlyconfigurethevirtual LANs(VLANs)thatcontrolaccess tohostservers.
VirtualPrivate Networks(VPNs)
RelyonVPNconnectionsforall remoteadministration.
RoutingandRemote Access(RRAS)
Implementaremoteaccess authenticationservicefor administratorsworkingremotely.
SecureSockets Layer(SSL)
Ensurethatallremotecommunications aswellasinternalintraserver communicationsareencrypted.
Table13-1. ApplyingtheCDStoResourcePools(continued)
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Layer
Contents
Contents
PublicKey Infrastructures (PKIs)
Eitherpurchasetrustedserver certificatesforyourserversor implementActiveDirectory CertificateServices(ADCS)insupport ofaninternalservercertificate deploymenttosupportencrypted communicationswithhostservers.
Identityfederation
Notapplicablesincethereisnoneed forfederationinthisinfrastructure.
NetworkAccess Protection(NAP)
ImplementNAPifpossibleto ensurethatallmachinesthatlink totheresourcepoolhaveapproved healthstatus.
Table13-1. ApplyingtheCDStoResourcePools(continued)
SecureVirtualServiceOfferings YourVirtualServiceOfferingswillalsorequiretheapplicationoftheCDS.Butinthis case,youneedtofocusonallofthesecurityelementsyounormallyfindinaproduction network.Assuch,theitemsidentifiedinTable13-2areprovidedforyourreviewonly
Figure13-4. Scopeofprotectionfortheresourcepool
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becausecoveringthefullimplementationofsecuritysettingsforaproductionnetworkis beyondthescopeofthisbook.However,youcanrelyonthistableasatypeofchecklist thatidentifieshowthesecurityofyourproductionnetworkshouldbeaddressed.
Layer
Contents
Contents
Layer1: Critical information
Datacategorization
Categorizetheinformationthatmakes yourorganizationruntoidentifythe differentlevelsofprotectionyouneed toapplytothem.
Applicationhardening Makesureyourvendorsandyour internaldeveloperscreatesecurecode, andrelyonbestpracticestoharden eachapplication. Layer2: Physical protection
Physicalenvironment
Thereislittlephysicalaccesstovirtual machinesexcepttothefilesthatmake itup. Protectionforthesefilesisaddressedin theresourcepoolCDS,asisthesecurity ofthephysicalenvironmentwherehost serversreside.
Physicalcontrols
Notapplicablesincethisisappliedat theresourcepoollevel.
Communications
Makesureallusers,including administrators,understandtheir responsibilitiesintermsofsecurity practices.However,endusersdonot needtoknowifthemachinesthey interactwitharevirtualorphysical. Thisinformationisprivilegedand shouldbeavailabletoadministrators andtechniciansonly.Bothshould bebriefedontheprivacyofthis information.
Surveillance
Beasvigilantaspossibleandcontrol USBdeviceaccessonphysicaldesktops withintheproductionnetwork.
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Layer
Contents
Contents
Layer3:OS hardening
Securityconfiguration
Payspecialattentiontothefollowing: Servicehardening. Securityconfigurationsettingsfor virtualservers. Limitedroleinstallationsoneachvirtual machinewithonlyrequiredcomponents fortheserviceitdelivers.Youmight evenconsidercreatingmoresinglepurposemachinestoavoidhavingto securemultiplerolesonthesameVM. IfyouarerunningWindowsServer, considerthefollowingaswell: BitLockerDriveEncryptionforservers playingcriticalroles. UserAccountControl(UAC)forall administratorsandallusers. DeviceControltoensurethat unauthorizedUSBdiskdrivescannotbe connectedtoanyaccesspoint,including anyphysicalPConthenetwork. BitLockerDriveEncryptionforhighly securenotebooks. Wirelessnetworkingsecurity.
Antimalware
Implementproperantimalware enginealongwithproperantivirus technologies.
Generaldirectory security
Implementtightpermissions management. Implementmultiplepasswordpoliciesto requirehighlycomplexpasswordsand perhapssmartcardsforadministrators. Tightendelegationofauthoritysettings onyourservers. Implementread-onlydomaincontrollers inremoteofficesifusingWindows.
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Contents Implementsoftwarerestriction policiestoensurethatnomalicious codeisallowedtoruninthe productiondomain.
Filesystem
SecurethefilesystemtoprotectVSOs. Implementaccess-basedenumeration tofurtherprotectinformation. RelyondigitallysignedWindows InstallerPackagesforallthird-party orcustomproductinstallations.
Layer4: Information access
Printsystem
Implementafullsecuritystrategyfor allprinters.
.NETFramework security(Windows)
Applicabletoanymachinethathasan applicationroleoranymachinethat includesPowerShell(inmostcases,this willbeeveryWindowsserverinthe VSOnetwork).
Webservices
ImplementtightWebserversecurityon allWebservers.
Systemredundancy
RelyontheprinciplesinChapter15 toensurebusinesscontinuityofkey VSOservers.
Useridentification
Relyonsmartcardortwo-factor authenticationforadministratorsin highlysecureenvironments. Highlysecureenvironmentswilluse two-factorauthenticationforallusers. Otherwise,usecomplexpasswordsfor allusers.
Securitypolicies
AssignproperpoliciesfortheVSO network.
Resourceaccess
Tightlycontrolallresourceaccess. ImplementEncryptingFileSystem (EFS)formobileusers.
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Layer
Contents
Contents Relyonlightweightdirectoriessuch asActiveDirectoryLightweight DirectoryServices(ADLDS)forcustom applicationresourceaccess.
Layer5: External access
Role-basedaccess control
Implementineveryapplicationas muchaspossible.
Accessauditing/ monitoring
Turnonauditingaswellasdirectory auditingtotrackallchanges.
Digitalrights management(DRM)
IfusingWindows,relyonADRights ManagementServices(ADRMS)to applyDRMtoalldocumentationthat iscopyrightedorsensitiveinany otherfashion.
Perimeternetworks
Configureserverfirewallswithcontrol accesstoallservers,especiallythosein theperimeternetwork. Applythebuilt-infirewalltoXPand VistaPCsandmobileworkstations.
VirtualPrivate Networks
RelyonVPNconnectionsforall remoteaccess.
RoutingandRemote Access
Implementaremoteaccess authenticationserviceforusers workingremotely.
SecureSocketsLayer
Ensurethatallremotecommunications aswellasinternalintraserver communicationsareencrypted.
PublicKey Infrastructures
IfusingWindows,implementActive DirectoryCertificateServices(ADCS) insupportofsmartcarddeployment andsoftwarerestrictions.Ifnot,usea third-partycertificationengine.
Identityfederation
IfusingWindows,relyonAD FederationServices(ADFS)forextranet accessifitisrequired.
NetworkAccess Protection
ImplementNAPtoensurethatall machinesthatlinktotheVSOnetwork haveapprovedhealthstatus.
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Virtual Service Offerings require more in terms of security settings than resource pools because they are designed to interact with end users and, therefore, have more servicesbuiltintotheinfrastructure.ThescopeofprotectionforVSOswilldependon the size of your organization. Certain security technologies are reserved for resource pools,assomearereservedforVirtualServiceOfferings.Forexample,thereislittleneed torundigitalrightsmanagementwithintheresourcepoolsincethisinfrastructureisnot aproductivitynetwork.Keepthisinmindwhenyoureviewthesecuritysettingsofthe servicesyourvirtualmachinesoffertoyourusers.
APPLYTHECASTLEDEFENSESYSTEM TOTHERESOURCEPOOL Toaddressthesecurityoftheresourcepool,allyouneedtodoisfollowtheguidelines inTable13-1.AddresseachofthelayersoftheCastleDefenseSystemonebyoneand makesuretheresourcepoolisassecureasitcanbe.Securitypracticeswilldifferbased onthehypervisoryouhaveelectedtorun.Theywillalsodifferbasedonthelevelof virtualizationyouhaveachieved.Forexample,ifyouonlyworkwithservervirtualization,youwillonlyneedtosecuretheenvironmentandtheVMsthatmakeitup.If youhaveelectedtoworkwithdesktopvirtualization,youwillneedtosecurethecore virtualmachinebecauseyoushouldbeworkingwithread-onlydesktopVMsthatare volatileandcanbeassignedtoanyuser.Ifyouareworkingwithapplicationvirtualization, then depending on whether you are using agent-based or agentless application virtualization(AppV),youwillneedtoconsiderhowyousecureandprotectyourvirtualapplications. Considerationsforeacharediscussedinthefollowingsections.
Layer1:CriticalInformation Thefirstplacetostartiswithwhatyouneedtoprotect.Intermsofresourcepools,you needtoprotecttwolayersofdata.
▼ T hevirtualdiskdrivesthatmakeupeachvirtualmachineintheVSO network.Thisincludesonlineandrunningmachines,offlinemachines,virtual appliances(VAPs)orvirtualmachinetemplates,andanyothervirtualmachine container.
▲ D atacontainedwithinthemanagementdatabase.Thedatabaseengineyouuse tostorethisdatawillvary,dependingonwhichhypervisoryouhaveselected torun,butmosteveryhypervisormanagementenginereliesonadatabaseto storeinformationsuchassettingsfiles,policiestiedtoVMs,hostconfiguration settings,andmore.
Eachoftheserequiresspecialattention.
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ProtectVirtualDiskDrives Protectingvirtualdiskdrivesmeansmorethanprotectingthe.vhdor.vmdkfilesthat makeupyourvirtualmachines.Youmustalsoprotectconfigurationfiles,snapshotfiles, logfiles,andanythingelsethatcanmakeupavirtualmachineinyournetwork.This wouldalsoincludeanytemplatesorvirtualappliancesyouobtainedinOpenVirtualizationFormat(OVF),aswellastheVAPsyoucreatein-house,suchasWindows-basedVM templates.ItwouldalsoincludetheISOfilesyouusetostoresourceoperatingsystems andotherservertechnologies. Inmostcases,yourvirtualmachinesandrelatedfileswillbelocatedinuptosix differenttypesofcontainers.
▼ S erverVMslocatedinthedatacenterwillresideinsomeformofshared storage.Whetheryouusenetworkattachedstorage(NAS)orastoragearea network(SAN),thestoragecontainer’senginewillprovidetechnologiesand featuresinsupportofdataprotectionandsecurity.
■ S erverVMslocatedinremotesiteswillbeinanall-in-oneboxserver,which shouldbeusingsharedstorageaswell.Relyonthestorageinfrastructure’s capabilitiestosecurethecontents.
■ S haredcontent,suchasISOimagesandsourcesoftware,isusuallycontained withinalibraryfileshare.ForVMwareandXenServer,thisisusuallya NetworkFileSystem(NFS)share,butbothcanalsoworkwiththeCommon InternetFileSystem(CIFS),whichisusuallyfoundinWindows.Ineithercase, makesureyourdisksareformattedinasystemequivalenttoNewTechnology FileSystem(NTFS)andprovidetightfilesharepermissions.Thiscontainer mightalsostoreofflineVMsorOVFfiles.Besuretoprovidetightprotection forthefoldersthatcontainthesefiles.
■ U nitandfunctionaltestinganddevelopmentVMsmaybetransportedin externalUSBdiskdrives.UseatleastNTFStoformatthedrivesifyourun yourtestanddevelopmentenvironmentsonWindows.Youmightalso considerusingtheEncryptedFileSystemtofurtherprotectthecontentsof thesedrives.
■ D ataprotectionstrategiesinvolvebackinguptheVMsandcreatingVM snapshots.Theseshouldbekeptcentrallywithinthedatacenterandshouldbe hostedonsharedstoragetoprovidethehighestlevelofsecurity.Ifyouback uptotape,makesureyourofflinevaultistotallysecure,asisyourmethodof transporttothevault.
▲ B usinesscontinuitystrategiesforVMsinvolvereplicationfromonelocationto another,usuallyfromthecoredatacentertoaremotebackupdatacenter.Make sureyouimplementthesameorsimilarsecuritystrategiesinbothdatacenters.
Anytimeamachineismadevirtual,itismadetransportable.Inaddition,virtualmachines are self-contained and will often include highly sensitive information, such as
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passwordsandaccessrights.IfsomeoneisabletowalkoffwithyourVMswithoutyour knowledge,theycantakeallthetimeintheworldtodecipherthemanddiscoveryour most guarded secrets. Make sure your administration personnel are completely trustworthytoprotectthisinformation.
ProtectManagementData Every hypervisor management system runs on a database. VMware VirtualCenter runsoneitherMicrosoftSQLServeroronanOracledatabase.Italsoworkswiththe MicrosoftSQLServer2005ExpressEdition,butthisengineisonlysupportedforproduction environments with up to five host servers. Microsoft System Center Virtual MachineManageralsorequiresadatabase,andbecauseitisMicrosoft,thedatabase runsinSQLServer. TheexceptionisCitrixXenCenter.Itdoesnotrelyonadatabase.Instead,itstores all configuration data inside Extended Markup Language (XML) files on each host. Hostconfigurationfilesarecollectedtogetherwhenyoubuildresourcepoolsorpools ofserverslinkedtogetherinahigh-availabilityconfigurationthroughamaster/slave relationship,whichresemblesthetraditionalprimaryversussecondaryDomainName System(DNS)serverrelationship.Becauseeachhostcontainsacopyofalloftheconfigurationfilesfortheresourcepool,itcanactasamasterwheneveroneoftheother hostsfails. Whenyourunhypervisorsdirectlythroughthehypervisor’smanagementtool,for example,throughVirtualInfrastructureClientinVMwareorthroughHyper-VManager inWindows,youdonotuseadatabasebecausesettingsarelocatedonthehostserver alone.UnlikewithXenCenter,thesefilesarenotreplicatedfromonemachinetoanother, thoughyoucouldeasilydosoifyouwant. Centralizingmanagementdataintoadatabasemakessenseaslongasyoumakesure thisdatabaseisalwayshighlyavailable(seeChapter15).However,therearetwoaspects youmustconsiderfromthedatasecuritypointofview.
▼ Y oumustmakesurethatonlytheappropriatepeoplehaveaccesstothedata heldwithinthemanagementdatabase.Inaddition,secureyourdataattwo levels.First,protectitthroughthesamemechanismsyouusefordocuments becausedatabasesstoreinformationinfilesjustlikedocuments.Second, protectitthroughthefeaturesofthedatabasesystemusedtostoreit.
▲ Y oualsohavetomakesurethatyourinstallationofthedatabaseengineis hardenedandprotected.SQLServerespeciallyhasagreatreputationforbeing wideopen.Ofcourse,Microsofthasdonealotofworktotightenthesecurity aroundSQLServerintheir2005and2008releases,butthisisnoreasonwhy youshouldn’tmakesuretheinstallationandconfigurationofthedatabase engineisastightasitcanbe.
Whetherthedataisindistributedrepositoriesorwithinacentraldatabase,makesureit isprotectedatalltimes.
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NOTE For information on SQL Server security best practices, look up download.microsoft .com/download/8/5/e/85eea4fa-b3bb-4426-97d0-7f7151b2011c/SQL2005SecBestPract.doc. YoucanalsorelyontheMicrosoftBaselineSecurityAnalyzertocheckyourSQLServerinstallation (http://technet.microsoft.com/en-us/security/cc184924.aspx). For information on Oracle database securitybestpractices,lookuptheOraclesecuritytechnologycenteratwww.oracle.com/technology/ deploy/security/index.html.
Layer2:PhysicalProtection Thesecondlayerofsecuritylieswiththephysicalprotectionofyourcomputingsystems. Physicalprotectiondealswithavarietyofissues.Aphysicalserverthatislocatedunder a stairway in some regional office cannot be considered secure by any means, unless, ofcourse,itiscontainedwithinapropersystemcasing,suchasthoseprovidedbyKell Systems(www.kellsystems.com). Asyouwillimagine,thislayermostlyappliestoresourcepools,butitalsoextends toyourPCsoranyphysicalsystemthathastherighttoconnecttoyournetwork,even iftheyonlyinteractwithVSOs.Ofcourse,sincemostorganizationsmovingtoavirtual infrastructure are moving from a physical infrastructure, most of the elements in this layershouldalreadybefamiliartoyouandyoushouldalreadyhavemostofitselements inplace. Theelementsthatyouneedtocoveratthephysicalprotectionlayerinclude:
▼ Geographicallocation Isthephysicallocationofyourbuildingswithin environmentallyendangeredlocations?Istherethepossibilityoffloods, avalanches,orcave-insthatmayaffectthebuildingsyoudobusinessin?Are theynearroadswhereaccidentsmayaffectthebuilding?
■ S ocialenvironment Areyourpersonnelawarethatphysicalaccesstoany computingequipmentshouldbeprotectedatalltimes?Aretheyawarethat theyshouldneverdivulgepasswordsunderanycircumstance?
■ B uildingsecurity Areyourbuildingssecure?Areentriesguardedandare visitorsidentifiedatalllocations?Areguestsescortedatalltimes?Arerogue computingdevicesallowedwithinyourbuildings?Istheelectricalinputto thebuildingprotected;doesithaveabackup,especiallyfordatacenters?Isthe building’saircontrolprotectedanddoesitincludeabackupsystem?Istherea goodfireprotectionplaninallbuildings?Isthewiringinsideandoutsidethe buildingsecure?Arewirelessemissionssecure?
■ B uildingconstruction Isthebuildingconstructionsafe?Arethewalls inyourdatacentersfireproof?Aredatacenterdoorsfirebreaks?Arefloors coveredinantistaticmaterial?Ifthereisageneratoronpremises,isitina safeandprotectedlocation?Doesthecomputerroomprotectcommunication equipmentaswellascomputerequipment?Doesthebuildingincludesecurity camerastoassistsurveillance?
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■ S erversecurity Areserverswithinlockedroomsorlockedcabinetsinall locations?Isaccesstoserverroomsmonitoredandprotected?Aretheservers themselvesphysicallysecured?Isaccesstophysicalserverscontrolled? WindowsServer2008supportstheuseofsmartcardsforadministrator accounts.Inhighlysecureenvironments,youshouldassignsmartcardstoall administrators.Withnewlow-costsmartcardoptions,especiallyUSBsmart cards,therearefewreasonsnottoimplementthispolicy.
■ B IOSsecurity Allcomputingdevicesshouldhavesomeformofprotection attheBIOSlevel.Forphysicalhostservers,thisshouldalsoincludepower-on passwords.Forallsystems,BIOSsettingsshouldbepassword-protectedand likeallpasswords,thesepasswordsshouldbehighlyprotectedandmodified onaregularbasis.Newdesktopmanagementinterface(DMI)management toolsallowforthecentralizationofBIOSpasswordmanagement.
■ S tagingsecurity Areallphysicalsecuritypoliciesextendedtostagingrooms wherephysicalsystemsareinstalled?Itdoesn’tdotohavehighlysecure computerroomswhenthestagingfacilitiesarewideopen.Notethatwith built-inhypervisors,stagingahostserverismuchlesstime-consumingthan traditionalsystemstaging,butifyourunMicrosoftHyper-Vorifyoustill buildphysicalPCs,youwillrequireastagingarea,whichmustbesecured.
■ P Csecurity Areworkstationsandmobiledevicessecure?Arehardware identificationsystemssuchasbiometricsandsmartcardsusedformobile devices?Isdataonthemobiledevicesecurewhenthedeviceisintransit?Are externalconnectionsfromthemobiledevicestotheinternalnetworksecure? DoyoucontroltheconnectionofrogueUSBdevices?
■ N etworksecurity Arethenetworkanditsservicessecure?Isitpossiblefor someonetointroducerogueDynamicHostConfigurationProtocol(DHCP) servers,forexample?WithWindowsServer2008,aswithWindows2000/2003, DHCPserversmustbeauthorizedtoallocateaddresses,butonlyiftheyare Windows-basedDHCPservers.Isthereawirelessnetworkinplace?Isit secure?Canroguewirelessuserspenetratethenetwork?
▲ Redundancy Areyourcriticalsystemsredundant?Thisshouldincludeall systems—datasystems,fireprotection,InternetandWANconnections,air conditioning,electrical,andsoon.
Allofthephysicalaspectsofyourinstallationsmustbemaintainedanddocumented.In addition,appropriateaspectsofthephysicalprotectionplanmustbecommunicatedto employeesatalllevels.Note,however,thathostserversystemswillnotrequireuserinteractionand,therefore,canbeomittedfromthegeneralend-usercommunicationplan, butnotfromtechniciansandadministrators. Finally,physicalprotectionmustbesupplementedbyasurveillanceprogram.Once again,thisisapartthatcanbeplayedbypersonnelatalllevels.Eachemployeemustbe awarethattheycanandshouldparticipateinthesurveillanceofanysuspiciousactivityor thenotificationofanyuntowardeventthatmaycompromiseyourinformationsystems.
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Layer3:OperatingSystemHardening Theobjectofoperatingsystemhardeningistoreducetheattacksurfaceofyourservers andPCs.Todoso,youneedtoremoveanythingthatisnotrequiredonasystem.For hostserversthatrunbare-metalhypervisors,thishardeningprocessisstraightforward sincethehypervisorisalreadypareddowntothebareessentials. However, a host server infrastructure includes several different components (see Figure13-4again).
▼ Thehypervisor,whichislikeabare-metaloperatingsystem(OS)oneachhost
■ Theconsolesystem,whichinmostcasesrunsonWindowsservers
■ T hedesktopsorremotesystemsadministratorsusetoaccesstheconsole throughmanagementclients
■ T hedatabaseorfilerepositoriesthatstoreconfigurationandpolicyinformation abouttheresourcepool
■ ThestoragecontainersthatserveasarepositoryforallVMs
■ ThefilesharethatstoresallsourceandISOfiles
▲ Thesecuritycontextyouusetoassignadministrativerolesintheresourcepool
And,asmentionedpreviously,thestructureofeachoftheseelementswilldifferbased onthetypeofhypervisoryourun.Butnomatterwhichsystemyourun,youshould consider the following for each of the components that make up the resource pool infrastructure:
▼ Systemsecurityconfiguration
■ Antimalwarestrategy
■ Directoryservicesecurity
■ Filesystemsecurity
■ Printsystemsecurity
■ .NETFrameworksecurity(inWindows,especiallywithPowerShell)
■ Webserversecurity
▲ Systemredundancy
Eachoftheseelementsrequiresparticularattentionforresourcepools.
SystemSecurityConfigurationforHostServers Systemsecurityconfigurationinvolvestheapplicationofsecurityparametersduring themachinestagingprocess.Whenyouinstallamachine,especiallyaserver,youneed toperformsomemodificationstothedefaultinstallationtoensurethatyourmachine isprotected. For VMware ESX server, the operation is relatively simple; just set Security=high during the installation and it will automatically configure the hypervisor in a secure mode.ThisisthedefaultinstallationsettingforVMwareESX.Itautomaticallyencrypts
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alltraffictoandfromtheserver,usernamesandpasswordsareneversentincleartext, andnoFTPaccessisallowedtotheserver. ForCitrixXenServer,youmusthardenthehostOSthroughstandardLinuxsecuritypractices.ForMicrosoftHyper-V,youmustfirstmakesureyouinstallServerCore onyourhostsandthenhardentheinstallationasmuchaspossiblethroughstandard Windowssecuritypractices.Fortunately,WindowsServer2008alreadydoesagood jobofhardeningtheOSonitsown,especiallyServerCore,becauseitinstallsonlythe barestofcomponents—thecompleteinstallation,includingtheHyper-Vrole,isless than2.6GB—andthenyouaddtherequiredrolesandfeaturestotheserver.Sinceitis ServerCore,itdoesnotincludethe.NETFrameworkorInternetInformationServices bydefaultanditdoesnotincludeanygraphicaluserinterfacecomponents,suchas MicrosoftInternetExplorerorWindowsMediaPlayer. Inaddition,boththeCitrixXenServerandtheWindowsServer2008installations aretrue64-bitoperatingsystems,which,bydefault,containadditionalsecuritycomponents.However,at32MB,VMware’sESXiistightlycontrolledeventhoughitisa 32-bitengine. Since Windows Hyper-V and Citrix XenServer run on more complete operating systems,youshouldperformtwoadditionalactivitiesoneachserver.
▼ First,performsomepost-installationsecurityconfigurationmodifications.
▲ S econd,applysecuritytemplatestotheserverbyserverrole.InWindows, thissecondportionofthesystemconfigurationprocessreliesontheSecurity ConfigurationWizard(SCW)toautomaticallyapplysecuritysettingstoyour systembasedonitsrole.InLinux,youmayhavetouseathird-partysecurity configurationtooltotightensecuritysettings.
TightenOSsecurityasmuchaspossibletofullyprotectyourhostservers. NOTE ForinformationonsecuringHyper-Vhosts,seeChapter10ofMicrosoftWindowsServer 2008:TheCompleteReferencebyRuestandRuest(McGraw-Hill,2008).Forinformationonsecuring ESXServer,seetheTop10RecommendationsforImprovingVMwareESXSecurityathttp://blogs .vmware.com/vmtn/2007/02/top_10_recommen.html.
SystemSecurityConfigurationforConsoleServers Console servers mostly run on Windows Server. Ideally, you will be using Windows Server2008(WS08),sinceitisthemostsecureserverOSMicrosofthaseverreleased.But sincethisserverisaWindowsserver,youshouldperformaminimalinstallationand addnoadditionalrolestotheserverasmuchaspossible.IfyouareusingWS08,youwill needtoperformaFullInstallationsincetheconsolecomponentsrequiretheinstallation ofgraphicalcomponents. Inthiscase,youshouldprepareasecurityconfigurationwiththeSecurityConfigurationWizardandtightenanyandallofthecomponentsoftheserver.Removeoratleast disableanyunusedservices.SCWisthebesttooltosecureWindowsserversbecauseit providescompleteinformationoneachoftheitemsyouchoosetoenableordisable,lettingyouunderstandexactlywhatyouaredoing(seeFigure13-5).Inaddition,youcan
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Figure13-5. TheSecurityConfigurationWizardprovidesextensiveinformationoneachsecurity elementitapplies.
createtemplateswithSCWtoapplythesamechangestoanyotherconsoleserveryou needtocreateorinstall. YoucanrunSCWinauditingmodeifyouareunfamiliarwithit.Thisletsyougaina betterunderstandingofitsworkingsanddoesnotmakeanyactualchangestothesystem.Then,whenyouaremorefamiliarwiththetool,youcanuseittotightensecurity onyourWindowsservers. NOTE For more information on the Security ConfigurationWizard, go to http://technet.microsoft .com/en-us/library/cc771492.aspx.
AntimalwareStrategies Alothasbeensaidaboutrunningantimalwaresoftware,includingantivirussoftware,on hostsystems.IfyouarerunningHyper-VorXenServer,youshouldconsiderastandard
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Figure13-6. VMware’sVMsaferunsdirectlyonthehypervisorandprovidesfullprotectionforanyVM.
antivirusprogramforWindowsorLinux.Nofull-systemOSshouldrunwithoutthistype ofprotection,evenifitimpactssystemperformance. IfyouarerunningESXServer,youshouldrunVMsafe.VMsaferunsdirectlyonthe ESXhypervisorandprovidesapplicationprogramminginterfacesforcommonantivirus andantimalwaretoolstorunontopofit(seeFigure13-6).Becauseitrunsonthehypervisor,youdonotneedtoaddantimalwareorantivirustechnologiesinsidethevirtual machines.AnyVMyouplaceonahypervisorusingVMsafewillautomaticallybeprotected.VMsafescanscriticalVMcomponents,suchasmemory,CPU,network,anddisk resources.ItevenscansinternalVMprocessesforprotection. VMsafeprovidesanewwaytoprotectVMs.Forexample,ifyouruntheconsolesystemsinvirtualmachinesontopofahypervisorrunningVMsafewithaproperantivirus engine,youdonotneedtoaddtheoverheadofanAVengineinsidetheconsoleVM.This greatlyfacilitatesVMcreationandprovidesongoingprotectionforanyVM. NOTE TolearnmoreaboutVMsafe,gotowww.vmware.com/overview/security/vmsafe.html#.Note thatVMsafewasnotyetavailableatthetimeofwritingofthisbook. TheVMsafemodelisprovingtobesocompellingthatthedevelopersofXenvirtualizationcomponentsinLinuxdistributionsareworkingonasimilarfeature.Thisfeature shouldbeavailableinfutureiterationsforXen-basedhypervisors.
FileandPrintSystemSecurity Thefilesystemisalsoaportionofoperatingsystemhardeningthatsupportsasecureenvironment.IfyouarerunningWindows,youmustuseNTFS.Thereisnodoubtthatdespite itsreportedfailings,NTFSisanabsolutemustandapillaroftheCastleDefenseSystem. WithoutNTFS,thereisnoencryption.InLinux,youmustrunasecurefilesystem. Oneoftheimportantaspectsofsecurefilemanagementistheabilitytologallfile changesandalertorganizationswhenunauthorizedchangesoccur.Thiscanbedone in some form with file access auditing, but for critical data files, professional help is required.ThishelpcomesintheformofautilitysuchasTripwireforServers(www .tripwire.com/products/servers).Tripwiremonitorsallfilechanges,evendowntothe
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file’schecksumproperties.Therefore,itcanalertadministratorswhencriticalfileshave beenmodifiedbyunauthorizedpersonnel. Inaddition,NTFSsecurityhasbeenconsiderablyimprovedinWindowsServer2008. NTFSusestheconceptofinheritancetoapplyaccesspermissions.Italsoappliesstrong securitysettingstotheUsergroupforstabilitypurposes.Thismeansthatuserscanno longerrunlegacyapplicationsthatmodifyfileslocatedinsensitivefolderssuchasProgramFilesandWindows.Administratorswillneedtotakespecialmeasurestoensure thatlegacyapplicationswilloperateonWindowsServer2008systemsfornormalusers. WS08alsoincludesWindowsResourceProtection,afeaturethatisdesignedtorepairsystemfilesandregistryentrieswhendamagedbysoftwareinstallationsorotheruntoward events.MoreinformationonthesefeaturesisavailableintheWS08Helpsystem. MakesurethatallfilerepositoriesaresecuredthroughthebestfeaturesoftheOSthat supportsthem. Asforprintsystems,thereislittleneedforprintsystemswithinthehostinfrastructurebecauseallVMcommunicationsareperformedthroughRemoteDesktopConnection(RDC)andyoucansimplyconfigureRDCtoautomaticallyconnecttheprinterof yourowndesktoptotheremotesystem(seeFigure13-7).Thismeansyouhaveoneless elementtosecureinthehostinfrastructure.
Figure13-7. UsingtheRemoteDesktopConnectionsettings,youcanconnectlocalprinters toanysession.
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DirectoryServiceHardening Because consoles run on Windows, many organizations find it easier to configure an ActiveDirectorywithintheresourcepooltoprovidecentralizedaccesscontrol.Andif yourunHyper-V,evenonServerCore,youwillrequiretheimplementationofanActive DirectoryDomainServices(ADDS)directory. Ineithercase,youshouldcreatewhatiscalledautilitydirectory.Utilitydirectories useasimpleforeststructure,usuallyincludingasinglerootdomain.Sinceyouwillnot haveanyusersinteractingwiththisdirectory—onlyadministratorsandtechnicians— youcanrunutilitydirectoriesinhostenvironmentsbecauseyoudonotneedtoprovide protectionforroot-levelaccessinthedirectory. InhypervisorssuchasVMwareESXServer,youcanrelyontheutilitydirectoryto providerole-basedaccesstoconsolecomponents.SimplycreateaseriesofdifferentsecuritygroupsinADDSandassigneachgrouptothevariousrolessupportedinVirtualCenter(seeFigure13-8).Then,tieyourADDSsecuritygroupstotherolesintheconsole
Figure13-8. VMwareVirtualCenteroffersseveraldefaultaccessroles.
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Figure13-9. ConfiguringcustomaccessrolesinVirtualCenter
throughtheGroupscommand.VMwareoffersgranularcontrolsforrole-basedgroups (seeFigure13-9). TheCitrixXenServerhypervisordoesnotyet(atleastatthetimeofwriting)supportrole-basedaccesscontrol,sousingautilitydirectorywithitwouldonlybeuseful ifyourstoragecontainersranWindowsandyouwantedtocentralizestoragecontainer accesscontrol. WindowsHyper-Vmustberunwithinautilitydirectory;otherwise,allaccessroles wouldbecontainedinworkgroupsandlocatedoneachindividualhostserver.Therefore, you must centralize host server access throughADDS. Use the simplest form of thedirectory,butcontinuetousebestpracticesinADDSsecurity.Oncethedirectoryis available,youwillbeabletomapuserrolesforSystemCenterVirtualMachineManager (SCVMM).However,youwillneedtoconfiguretheuserrolesthroughWindowsServer Manager’s Local Users and Groups feature (see Figure 13-10).As with any Windows infrastructure, member servers control access through local groups, which are tied to correspondingdirectorygroups. NOTE For information on utility ADDS directory security, see Chapter 5 of Microsoft Windows Server2008:TheCompleteReferencebyRuestandRuest(McGraw-Hill,2008).
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Figure13-10. RolegroupsinSCVMMthroughWindowsServerManager
When you build your utility directory, you may consider placing this role on the sameserversrunningyourconsoleservicesforseveralreasons.
▼ F irst,theconsoleserversshouldbesettoautostartiftheyarerunningonVMs sothatyouhaveaccesstoinfrastructuremanagementtoolsassoonasyour hostserversarebootedup.Theutilitydirectoryservicealsoneedstoautostart toensureyoucanlogintotheenvironmentwhenitbootsup.
■ S econd,youwanttolimitthenumberofWindowsserversyouruninyour infrastructure—atleastifyouarenotusingaWindowshypervisor—tokeep theenvironmentassecureaspossible.Byplacingboththemanagementand thedirectoryroleonthesameservers,youminimizethenumberofWindows VMsyourequire.
▲ T hird,byintegratingthetwoservicestogether,youwillgainfasterthroughput forauthenticationsincedirectorycommunicationswillbedirect.
Onedrawbackisthatyoumustgivelocallogonaccesstosomeofthemorerestrained roles in the management console. However, you may not even require the restrained rolesinyournetwork,sothisissuemaywellbemoot.
FinalOperatingSystemHardeningActivities Additionalactivitiesarerequiredforyoutofinalizethehardeningofyouroperatingsystems.Thefirstinvolvesupdatesandpatches.Whilehypervisorsarerarelyupdated—yes,
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evenHyper-VifyourunitonServerCore—youmusthaveaproperpatchinginfrastructureinplaceforthem.Thisisonemorereasonwhyyoumustbuildsystemredundancy intoyourhostservers.Ifyouneedtoperformmaintenanceononehostserverandthe maintenancerequiresareboot,youmustbeabletomoveyourVMsofftoanotherhostfor thedurationofthemaintenancewindow. AsdiscussedinChapter7,VMwarereliesontheUpdateManagertoprovideitsinfrastructureforupdatesforboththehypervisorandtheVMsitruns(seeFigure13-11). Update Manager supports both Windows and Linux guest operating systems and the applicationstheyrun.YoubeginbycreatingbaselinepatchinglevelswithinUpdateManager.Then,oncethebaselinesarecreatedforbothhostserversandVMs,UpdateManager willensurethemachinesareupdatedtomeetthebaseline.Tofurtherprotectthestateof aVM,UpdateManagerwillautomaticallycreatesnapshotsoftheworkingVMbeforethe updateisapplied,lettingyoueasilyrollbackupdatesifsomethinggoesawry. Inaddition,UpdateManagercanpatchofflineVMswithoutexposingthemtothe network.Todoso,offlineVMsarebootedupintoanisolatedmodetoensurethatonce theyarerunningfortheupdateprocess,theydonotinterferewithproductionmachines.
Figure13-11. VMwareUpdateManagerwillupdateboththehypervisorandtheVMsitruns.
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However,theabilitytoautomaticallyupdateofflinemachinesisanessentialpartofany virtualizationimplementation,sinceonlyinthisinstancewillyouhavemultiplecopies ofaspecificmachine. Toprotecthypervisorsandtheworkloadstheyrun,UpdateManagerwillworkin conjunctionwithVMware’sDistributedResourceScheduler(DRS)tomoveVMworkloads to other hosts before a patch is applied to the current host. It moves the VMs backoncethenewlypatchedhostisbackupandrunning.Becauseitprovidesacritical roleforVMsandhosts,UpdateManagerispartofeveryeditionofVMware’sVirtual Infrastructure. Citrix XenServer includes a similar ability through its XenCenter management interface.Pool-widepatchingwillautomaticallycheckwiththeCitrixWebsitetoseeif patchesareavailableforXenServerand,ifapatchisavailable,moveworkloadsoffthe hostwithXenMotionbeforepatchingitinamethodsimilartoVMwareUpdateManager.Pool-widepatchingisperformedthroughawizardthattakesyouthroughtheprocess stepbystep.However,thiscapabilityisonlyavailablefortheXenServerhosts,notthe VMstheyrun.ForVMpatching,youneedtoturntoathird-partysolution. MicrosoftreliesonthefreeWindowsServerUpdateServices(WSUS)topatchboth hostsandVMs.WSUSwouldalsoberequiredifyourunWindowsVMsonXenServer, sinceXenServerdoesnotpatchVMs.WSUSmaintainsadatabaseofbaselinepatchlevelsfordifferentmachinetypes.Machinesarepatchedonascheduleyousetthroughthe Windows Update client within each version of Windows. Microsoft also offers other productsthatsupportpatching,suchasSystemCenterEssentialsforsmalltomedium firmsorSystemCenterConfigurationManagerforlargershops;butWSUSisfreeand scaleswell,soitmightbeallyouneed. WSUSalsoworkswiththeMicrosoftOfflineVirtualMachineServicingTool(OVMST), whichbringstogetheraseriesofPowerShellscriptsthatworkwithSystemCenterVirtual Machine Manager to launch an offline VM, create a snapshot, update it through WSUS,andthenshutitdown(seeFigure13-12).OVMSTreliesonmaintenancehoststo serviceofflineVMs.Maintenancehostsareusedtoavoidanyimpactonoperationalhost workloadsduringtheofflinepatchingprocess. NOTE More information on WSUS can be found at http://technet.microsoft.com/en-us/wsus/ default.aspx. Find out more about the Offline VM Servicing Tool at http://technet.microsoft.com/ en-us/virtualization/default.aspx.
NOTE BecauseXenServerrunsVMsintheMicrosoftvirtualharddisks(VHD)format,theMicrosoft OfflineVMServicingToolcanalsobeusedwiththeVMsXenServerruns. Finally,inordertocompleteyourOShardeningprocedures,youneedtoputinplace redundantsystemsatalllevels.Systemredundancymeansbuildingresilienceintoyour hostandmanagementserversandintotheservicestheydeliver.Morewillbecoveredin Chapter15asyoubuildadditionalresiliencethroughhighavailabilityclusters.
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Figure13-12. TheofflineVMservicingprocess
Layer4:InformationAccess Layer4dealswithuseridentificationandtheattributionofpermissionsallowingthem tooperatewithinyournetwork.Themostimportantoftheseforaninternalnetwork istheKerberossecurityprotocol.Alothasbeensaidonthisprotocol.Ithasmanyadvantages,oneofwhichisthatitoperatesinbothWindowsandLinux.Oneofitsbest featuresisthefactthatonceithasauthenticatedusers,theusersdonotneedtoreturnto theserverforauthorization.InKerberos,theusercariesrightsandpermissionswithin theaccesstokenthatisgrantedbytheKerberosserver.Thisaccesstokenisintheform
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oftheKerberosticketthatisgrantedtotheuseratlogon.Inaddition,theserverauthenticatestotheclient,makingsurethatitisauthorizedtograntuseraccesswithin its realm of authority. Finally, Kerberos also supports two-factor authentication. This two-factorauthenticationcanbeintheformofasmartcardorabiometricdevice,such asafingerprintingdevice. OneofthekeyelementsofaKerberosrealm—theKerberosequivalentofaWindows Active Directory domain—is the timestamp. Time synchronization is essential in Kerberosbecausetheauthenticationservermatchesthetimeoftheclient’srequestwithits owninternalclock.Ifthetimediffersbymorethantheallottedtime—setwithinyour accountpolicies—theKerberosserverwillnotauthenticatetheuser.
SecureUserIdentification User identification happens on many levels within a resource pool network. The mostobviousauthenticationisthroughtheADDSutilitydomainyoucreate.Forthis, youneedtosetglobalaccountpoliciesfortheutilityforestanddomain.Inaddition, authenticationoccursincross-machinescenarios.Localhostmachineauthentication will vary, depending on the hypervisor you use. With VMware, host machine authenticationiscentralizedthroughVirtualCenterandtiedtotheutilitydirectory,as discussedpreviously.InXenServer,hostmachineauthenticationiscentralizedthrough XenCenter by replicating machine configuration from host to host. In Hyper-V, host machine authentication uses the member server structure and can be centralized throughtheutilitydirectory. Relyontherole-basedauthenticationcapabilitiesofyourhypervisortocontrolwhich administratorandtechnicianhasaccesstowhat.
SecureLayer4ThroughGroupPolicyObjects Thebestwaytomanageauthentication,authorization,andauditingisthroughGroup Policy,whichisatthecoreofActiveDirectory.Forexample,yousetauditingofaccess controlsthroughaGroupPolicyobject(GPO).YoucanmodifythedefaultGPOswithin theutilitydomain,butasabestpractice,itiseasiesttocreateanewGPOanduseitto tightensecurityonallobjectsintheutilitydomain,aswellastrackadministratorand technicianoperationswithintheenvironment. FullydocumenteachGPOyoucreateanduseastructuredchangemanagement approachforanymodification,asyoushouldforanyaccesscontrolstructure. Thedefaultdomainpolicyistheaccountpolicyforthedomain.Sinceonlyonepolicy cancontainaccountinformation,thisinformationshouldbedefinedinasinglearea.Be carefulwhenworkingwiththispolicybecauseitcannotbedeactivated.Ifyoumakea mistakewhileeditingthispolicy,youwillaffecttheentiredomain.Thisisonereasonfor astructuredGroupPolicychangemanagementstrategy. TheelementsthatneedtobecoveredinthisaccountpolicyareoutlinedinTable13-3. AlloftheelementsoutlinedinthistablearefromtheComputerConfiguration|Policy| WindowsComponents|SecuritySettingsbranchofGroupPolicy.Onceagain,remembertodocumentallofyourGPOsettings.
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Section
Setting
Recommendation
Comments
24passwords
Attherateofonepassword changepermonth,thissetting rememberstwoyears’worth ofpasswords.
Maximum passwordage
42days
Thisisapproximatelyamonth andahalf.
Minimum passwordage
2days
Thisstopsusersfromchanging theirpasswordstoooften.
Minimum password length
8characters
Thisisthethresholdwhere passwordcrackersstarttaking longertobreakpasswords.
Account Enforce Policies/ password Password history Policy
Account Policies/ Account Lockout Policy
Account Policies/ Kerberos Policy
Passwordmust Enabled meetcomplexity requirements
Thisensuresthatpasswords containbothalphabeticand numericcharacters,both upper-andlowercase,aswell asspecialsymbols.
Storepasswords Disabled usingreversible encryption
Enablingthissettingisthe sameasstoringplain-text passwords.Thissetting shouldneverbeenabled.
Accountlockout 60minutes duration
Thissettingdetermineshow longanaccountislockedafter severalbadlogonattempts.
Accountlockout 3invalidlogon threshold attempts
Afterthreebadlogontries,the accountislockedout.
Resetaccount lockoutcounter after
60minutes
Thismustbeequaltoor greaterthantheaccount lockoutduration.
Enforce userlogon restrictions
Enabled (default)
Thisensuresthatusershave therighttoaccesseitherlocal ornetworkresourcesbefore grantingthemaKerberos ticket.
Table13-3. DefaultDomainAccountPolicyElements
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Setting
Recommendation
Comments
Maximum lifetimefor serviceticket
600minutes (default)
Thisstatesthedurationof thesessionticketthatisused toinitiateaconnectionwith aserver.Itmustberenewed whenitexpires.
Maximum lifetimefor userticket
10hours (default)
Thismustbegreaterthan orequaltotheprevious setting.Itmustberenewed whenitexpires.
Maximum lifetimefor userticket renewal
7days (default)
Thisdetailsthedurationof auser’sticket-grantingticket. Theusermustlogonagain oncethisticketexpires.
Maximum tolerancefor computerclock synchronization
5minutes (default)
Kerberosusestimestampsto granttickets.Allcomputers withinadomainare synchronizedthroughthe domaincontrollers.
Individuals only
Selecttrustedindividuals shouldbemembersofthis group.
Domain/ Domain Admins
Individuals only
Selecttrustedindividuals shouldbemembersofthis group.
Domain/ Administrators
Enterprise Admins Domain Admins
Thisgroupshouldcontain onlytrustedgroups.
Restricted Domain/ Groups Enterprise Admins
Table13-3. DefaultDomainAccountPolicyElements(continued)
TIP AllofthesettingsforKerberospolicyaresetatthedefaultWindowsServersettings,butsetting themexplicitlyassistsyourGroupPolicyoperatorsinknowingwhatthedefaultsettingactuallyis. Allofthesesettingsareappliedatthedomainleveltoensurethattheyaffectevery objectwithinthedomain.Infact,theaccountpolicyisacomputerpolicy.Thismeans thattheuserconfigurationportionoftheGPOcanbedisabled.
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TIP It is very important to ensure that you have a strong communications program to keep administratorsandtechniciansawareoftheimportanceofhavingacomprehensiveaccountpolicy withinyourresourcepoolnetwork.Alsoindicatetothemthesettingsinyouraccountpolicy.Finally, educatethemontheprotectionofpasswordsandtheneedforimmediaterenewalofpasswordsthey thinkmaybecompromised.Thiswillensurethatyourresourcepoolaccountpolicyissupportedby theverypeoplewhouseit.
Layer5:ExternalAccess Layer5normallyfocusesontheperimeternetworkandtheprotectionofyourinternal networkfromoutsideinfluences.Intoday’sconnectedworld,itisimpossibletocreate internalnetworksthatarecompletelydisconnectedfromtheexternalworld,evenwhen dealingwithhostnetworks.Forexample,anadministratormayneedtoperformwork fromhomeduringemergencies.Becauseofthis,youneedtosecuretheinternalresource poolnetworkasmuchaspossible,creatingabarrierthatmustbecrossedbeforeanyone canenter.Thisbarriercantakeseveraldifferentforms,butinthecaseoftheresource poolnetwork,itmeansthecreation,orratherthecontinueduse,ofyourperimeterenvironment.ThisenvironmentisoftencalledthedemilitarizedzoneorDMZ. Perimeter networks can contain any number of components, but in the case of aresourcepool,theycanbelimitedtoaseriesoffirewallsthatprotectsyourinternal network, and they should not include and contain Internet servers or extranet services. Resource pools do not have a perimeter network because they do not interact withusersanddonotprovideanyuser-relatedservices.Theydo,however,interact withremoteadministrators.Forthislevelofinteraction,youmustworkwitheither theSecureSocketsLayerorIPSecurity(IPSec)–basedVirtualPrivateNetworkconnections.You will also need a Public Key Infrastructure in support of SSL because SSLcommunicationsarevalidatedthroughservercertificates.Youshouldalsoensure thatanyremotesitewilluseIPSecforserver-to-servercommunications,especially whenreplicatingvirtualmachineimages.Youmayalsodeterminethatyouneedto implement Network Access Protection to ensure that any system that connects to theresourcepoolisalwaysup-to-dateintermsofsecuritypatchesandantimalware protection. VirtualServiceOfferings,becauseoftheirproductivityfocus,haveaperimeternetworkandthereforeneedprotectionatmultiplelevels.PerimeternetworksforVSOscan includeahostofservices,butmostoftentheyinclude:
▼ Remoteconnectionsformobileendusersactingoutsideyourpremises
■ Federationservicesforpartnerorganizations
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■ NetworkAccessProtectionforanysystemthatwantstoconnecttothenetwork
▲ P ublicKeyInfrastructurestoprovideprotectionfortheapplicationsyoumake availableintheperimeteraswellasinsupportofsmartcarddeployments
ThelevelofimplementationismorecomprehensiveintheVSOsthanitisintheresource poolsinceresourcepoolsonlyinteractwithadministrators. CAUTION Sinceyourperimeternetworkwillbemadeupofvirtualmachines,youshouldrelyon theinternalsettingsofyourhypervisortocreatevirtualLANs,segregatingthevirtualmachines thatbelongtoeachpartofyourVSOnetwork.Youmightalsoconsiderplacingperimetermachines on specific host servers and make sure they are never intermingled with machines from the Intranetzone.
SecureWindowsServerswiththeWindowsServer FirewallwithAdvancedSecurity Oneofthefirsttoolsyoumustworkwithwithintheperimeter—aswithallserversin any zone of your network—is the Windows Server Firewall with Advanced Security (WSFAS).TheWindowsFirewallisbuiltintoeveryeditionofWindowsandisinstalled bydefault.Infact,whenyouinstallWS08,WindowsFirewallissettodenyallremoteaccess.Then,asyouconfigurerolesforyourserver,youmodifythedefaultfirewallpolicy toopenandcontrolspecificnetworkports. ThedifferencebetweenthebasicfirewallandtheWSFASisthatthelattercombines afirewallwithIPSecmanagementintoonetooltoprovideintegratedsecurecommunicationsmanagement.ThismeansthatyouuseWSFAStomanageinternalandexternal servercommunicationsaswellasVirtualPrivateNetworkconnections.WSFASiscontrolledthroughGroupPolicyandcanbesettoapplythesamerulestoallsystems(see Figure13-13). Alotmorecanbesaidonthefirewall,butbasically,youshouldrelyasmuchaspossibleontheSecurityConfigurationWizardtohelpyouproperlyconfigurefirewallrules basedonserverroles.Thiswillgoalongwaytoprotectingyourmanagementandother servers,wherevertheyareinyournetwork. Notethatinmostperimeternetworks,WSFASisnotenoughonitsown.Mostorganizationswillalsoincludeeitherhardware-basedprotectiontechnologiesorsoftwarebasedstatefulinspectiontools.Itisalsogoodpracticetoimplementsomeformofintrusiondetectionintheperimeter. NOTE For more information on the Windows Firewall, go to http://technet.microsoft.com/en-us/ network/bb545423.aspx.
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Figure13-13. ControllingWSFASthroughGroupPolicy
UsetheSecureSocketsLayertoProtectCommunications Communicationsbetweentheadministrativeworkstationsandthehostserversshould alwaysbeencrypted,whethertheyoriginateinsideoroutsideyournetwork.Infact,to furtherprotectyouradministrativecommunications,youshouldcreateaspecificVLAN andplaceallofthehostandadministrativemachinesonit.Thiswilllimittheabilityof anyotheruserorservicetointeractwiththesemachines. But even then, you must encrypt all communications. When you install VMware ESX with the Security=High switch—the default setting, as mentioned earlier—it automaticallygeneratescertificatesforthehostserversandreliesonthemtoencryptall communicationstoandfromtheserver.However,forcommunicationstoworkproperly
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withtheSecureSocketsLayer,eachmachineinthecommunicationlinkmusttrustthe originatorofthecertificate.Sincethecertificatesareself-signedoneachhostserver,you havethreechoices.
▼ I mporteachoftheself-signedcertificatesintoyourmanagementmachinesto ensuretheyaretrustedcertificates.
■ I mplementyourowninternalPublicKeyInfrastructure—whichcaneasilybe donewithWindowsServerADCertificateServices—andintegrateitwithyour utilitydirectory.Anymachinethatispartofthisdirectorywillautomatically trustanyofthecertificatesyougeneratethroughit.Thenyoumustreplacethe self-signedcertificateswiththenewcertificatesyougenerate.
▲ O btaintrustedcertificatesfrompubliccertificationauthoritiessuchasVerisign, Thawte,Entrust,orothers.Usethesecertificatestoreplacetheself-signed certificatesonyourservers.Sincethepublicauthoritiesareautomatically trustedbymostclientsystemsandwebbrowsers,thesenewcertificateswill betrustedwithoutfurthereffort.YoucanalsolooktonewSubjectAlternate Name(SAN)certificates.SANcertificatescanincludemultiplenameswithin thecertificate,lettingyouaddallofthenamesofyourhostserversintoone certificateandusethesamecertificateonallservers.However,youmust updatetheSANcertificateeachtimeanewhostisadded.
IfyouareusingWindowsHyper-V,youwillalsobeabletorelyonthenewSecure SocketsTunnelingProtocol(SSTP).Traditionally,VirtualPrivateNetworkconnections inWindowsnetworksreliedontheIPSecprotocol,whichprovidesanend-to-endconnectionatthenetworkinglayer.However,IPSecVPNscannotworkineverysituation. Forexample,whenyouuseNetworkAddressTranslationdevicesorevenwebproxy servers,yourIPSecVPNconnectionwillbeblockedatthegate.Inaddition,IPSecVPNs aremorecomplextoimplementandrequireyoutohavesomedegreeofcontroloverthe endpointorclientsystemmakingtheconnectionfromtheexternalworld.Asyouknow, thisisoftennotthecase. This is one reason why Microsoft has implemented the Secure Sockets Tunneling Protocol.SSTPreliesonHTTPovertheSecureSocketsLayer,orHTTPS,tocreateVPN connectionsoverport443.SSTPsupportsNetworkAccessProtectionaswellasIPv13. WhenyoucreateanSSTPVPN,theclientestablishesasingleconnectiontotheinternal serverandalltraffictravelsoverthisconnection.Youcannot,however,useittocreate site-to-siteconnections. SSTPreliesonPKIcertificatestocreateconnections.TheservershostingSSTPconnections must have installed certificates that include the ServerAuthentication or the All-PurposeEnhancedKeyUsagepropertyinordertoacceptSSTPconnections.SSTP VPNsarepartoftheNetworkPolicyandAccessServicesserverroleandmustbemanagedthroughtheRoutingandRemoteAccessServicesconsolenode. NOTE ForacompleteoverviewofSSLVPNS,seeTheCaseforSSLVirtualPrivateNetworksat www.reso-net.com/articles.asp?m=8#cundertheAdvancedPKIsection.
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RelyonanInternalPublicKeyInfrastructure PKIimplementationscanbequitecomplex,especiallyifyouneedtousethemtointeract withclientsandsuppliersoutsideyourinternalnetwork.Themainissueatthislevel isoneofauthority:Areyouwhoyousayyouareandcanyourcertificatesbetrusted? Whenthisisthecase,youshouldrelyonathird-partyauthorityspecializinginthisarea tovouchforyouandindicatethatyourcertificatescanandshouldbetrusted.WS08can playasignificantroleinreducingPKIcostsinthesesituations.Sinceitincludesallof the features required to implement a PKI service throughActive Directory Certificate Services(ADCS),allyouneedtodoisacquiretherootservercertificatefromanexternal source.Thiscertificatewillthenbeembeddedintoeverycertificateissuedbyyourinfrastructure.Itwillprovetoyourclients,partners,andsuppliersthatyouarewhoyouare andyouwon’thavetoimplementanexpensivethird-partyPKIsolution. Butyoudon’tneedthistypeofcertificateforthepurposesoftheresourcepoolnetwork since you control all of the systems within the network and you don’t need to proveyourselforyourorganizationtothem.ADCSsupportsseveraltypesofsecurity situations.Youcanusethemto:
▼ Securewebservices,servers,andapplications
■ Secureanddigitallysigne-mail
■ SupportEncryptingFileSystem
■ Signcode
■ Supportsmartcardlogon
■ SupportVirtualPrivateNetworking
■ Supportremoteaccessauthentication
■ S upporttheauthenticationofActiveDirectoryDomainServicesreplication linksoverSimpleMailTransferProtocol(SMTP)
▲ Supportwirelessnetworkauthentication
WS08providestwotypesofcertificateauthorities(CA):StandaloneandEnterprise.The latterprovidescompleteintegrationwithADDS.TheadvantageofEnterpriseCAsisthat sincetheircertificatesareintegratedwiththedirectory,theycanprovideauto-enrollment andauto-renewalservices.ThisiswhythePKIserviceyouimplementintheresource poolnetworkshouldbebasedonEnterpriseCAs. PKIbestpracticesrequirehighlevelsofphysicalprotectionforrootcertificateauthorities. This is because the root CA is the core CA for the entire PKI hierarchy. If it becomescorruptedforsomereason,yourentirePublicKeyInfrastructurewillbecorrupted.Therefore,itisimportanttoremovetherootCAfromoperationonceitscertificateshavebeenissued.Sinceyouwillremovethisserverfromoperation,itmakessense tocreateitasastand-aloneCAwithinavirtualmachine(removinganenterpriseCA fromthenetworkwillcauseerrorsinADDS).
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CAUTION RootCAsshouldberemovedfromoperationfortheirprotection.Thisiswhytheideal configuration for root CAs should be in virtual machines.Taking a virtual machine offline is much easierthanaphysicalmachine.Inaddition,thevirtualmachinecanbeplacedinasuspendedstate indefinitely,makingiteasierandquickertobringbackonlinewhenitisneeded. PKI best practices also require several levels of hierarchy. In fact, in PKI environmentsthatmustinteractwiththepublic,itmakessensetoprotectthefirsttwolevelsof theinfrastructureandremovebothfromthenetwork.ButinaninternalPKIenvironment,especiallyonethatwillmostlybeusedforsecurecommunicationsintheresource pool,twolevelsaresufficient.SubordinateCAsshouldbeenterpriseCAssothatthey canbeintegratedwithADDS.InordertoaddfurtherprotectiontothesubordinateCA, donotinstallitonadomaincontroller.Thiswillreducethenumberofservicesrunning ontheserver. EvenifyourPKIenvironmentwillbeinternal,youshouldstillfocusonaproperPKI design.Thismeansimplementingaseven-stepprocess.
1. R eviewWS08PKIinformationandfamiliarizeyourselfwithkeyconcepts. Anexcellentplacetostartisonlineathttp://technet2.microsoft.com/ windowsserver2008/en/library/532ac164-da33-4369-bef0-8f019d5a18b81033 .mspx?mfr=true.
2. D efineyourcertificaterequirements.Identifyalltheusesforresourcepool certificates,listthem,anddefinehowtheyshouldbeattributed.
3. C reateyourPKIarchitecture.Howmanylevelsofcertificateauthoritieswill yourequire?HowwillyoumanageofflineCAs?HowmanyCAsarerequired?
4. C reateormodifythecertificatetypesyourequire.Determineifyouneedtouse templates.Templatesarethepreferredcertificateattributionmethod.
5. C onfigurecertificateduration.Durationaffectstheentireinfrastructure.Root CAsshouldhavecertificatesthatlastlongerthansubordinateCAs.
6. I dentifyhowyouwillmanageanddistributecertificaterevocationlistsas wellaswhichADCSrolesyouwanttoincludeinyourinfrastructure.Thiscan includeWebEnrollmentandOnlineRespondersinadditiontoCAs.
7. I dentifyyouroperationsplanforthecertificateinfrastructureinyour organization.Whowillmanagecertificates?Whocanprovidethemtousers? Ifsmartcardsareinuse,howaretheyattributed?
Theresultshouldprovidethearchitectureyouintendtouse(seeFigure13-14). ConsidereachstepbeforedeployingADCS.Thisisnotaplacewhereyoucanmake manymistakes.ThoroughlytesteveryelementofyourADCSarchitecturebeforeproceedingtoitsimplementationwithinyourresourcepoolnetwork.Finally,justaswhenyou createdyoursecuritypolicytodefinehowyousecureyourenvironment,youwillneedto createacertificationpolicyandcommunicateittoyouradministrativepersonnel.
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Figure13-14. PotentialADCSarchitectures
NOTE FormoreinformationonPKIandtheworldoftrustitsupports,gotowww.reso-net.com/ articles.asp?m=8#c. For information on implementing and working with ADCS, see Chapter 16 in MCTSSelf-PacedTrainingKit(Exam70-640):ConfiguringWindowsServer2008ActiveDirectoryby Holme,Ruest,andRuest(MicrosoftPress,2008).
COMPLETETHERESOURCEPOOLSECURITYPOLICY TheCastleDefenseSystemprovidesastructuredapproachtothedesignofasecurity policy.Butitcannotstandalonetodefendyourcriticalresources.Itmustbesupplemented by a defense plan, a plan that includes both reactive and proactive defense measures. This means additional defenses at several levels, especially in terms of systemresilience.
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Therearealsoongoingoperationsthatmusttakeplaceatregularintervalstoensure that your defense system is constantly monitored and that your reaction plans work properly.Simulationsaregoodpractice.Youwillseehowyourespondandalsoifyour responseplanisadequate.Youdonotwanttofindyourselfinasituationwheretheonly responseisunpluggingasystem,especiallyahostsystemwithmultipleVMsrunning ontopofit. One of the keys to a solid response plan is ensuring that everyone in the organization knows and understands their role in the plan. Resource pools bring considerablechangetoyournetwork,especiallyintermsofthetypesofservicestheyrun.It isimportantthatthesechangesbefullyunderstoodbyyouradministrativestaff.Itis alsoimportantthatyouidentifyeachnewrolewithinyouroperationsaswellasthe modificationsyoumustbringtoexistingroles.Finally,tosupportyoursecuritypolicy toitsfullest,youneedtolimitthedelegatedrightsyouassigntoadministratorsand operatorswithinyournetwork.
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E
venthoughyouhavedoneyourbesttoensurethesecurityofyourserversand services, disasters can always happen, and servers, both host and virtual, can alwaysgodown.Thisiswhyitisimportanttoprepareforsystemrecovery.No system is perfect, but the more protection levels you apply to your systems, the less chance you have of losing data and experiencing downtime. Therefore, you need to implementdataprotectionstrategiestosupplementyoursecuritystrategies. Recoveringsystemsisneveraneasytask.Thebestwaytoavoidhavingtorecover systemsisbyusingamultilayeredprotectionstrategy.Butifyoudogettothestage where a recovery operation is required, you must have a detailed strategy to follow. Like every other operation in the virtual infrastructure, recoveries must be planned. Yourrecoverystrategymustbeginwithanunderstandingofthehypervisor’sbuilt-in capabilitiesfortheprotectionofvirtualmachinestates.Onceyou’refamiliarwiththe toolsthehypervisorofferstohelpyouprotectsystems,youcanoutlineoradjustyour protectionstrategy.
DEVELOPYOURSYSTEMPROTECTIONSTRATEGIES Systemprotectioninavirtualinfrastructuremustfocusonseveralkeyelements.
▼ T hereislittleneedtobackuphostserverssincetheyareredundant,and inmostcases,youcaneasilyre-createahostserverthroughtheintegrated hypervisorsnowavailable.
■ Y oumustalsoprotectthemanagementdatabaseandthemanagementvirtual machines(VMs)foryourresourcepool.Themanagementdatabaseespecially mustbeprotectedifyouwanttoensurethatyourresourcepoolcontinues tooperateproperly.AsforthemanagementVMs,youwouldusenormal VMprotectionmeasures.
■ Y oucaneasilyprotectvirtualmachinesthroughthesnapshotcapabilityof eachhypervisor.Youcancreateupto512snapshotsperVM.Asnapshotis acaptureofthecurrentstateofaVM,astateyoucanreturntoatanytime. Thisstatecapturesalloftheoperatingsystemsettingsandconfiguration,the applicationstate,andallofthedatacontainedwithintheVMatthetime.For mosthypervisors,snapshotsareusuallystoredwithintheresourcepool’s librarystore.Insomecases,forexampleVMware,thesnapshotsarestoredin thevirtualmachinefolder.
■ Y oucanbackupthefilesthatmakeupavirtualmachine,capturingallofits contentandthereforeprotectingallofthedatacontainedwithinit.
▲ Y oucanbackupthecontentsinsideavirtualmachine,justasyouwould normallybackupanyphysicalmachine.
Thereisalotofdiscussiononthemarketconcerningthelasttwopoints.Alotofpeople tendtousethelaststrategy,backingupthecontentsofeachVMandusingtraditional recovery strategies for their VMs. However, the very fact that machines are now virtualandarestoredonsharedstoragecontainersshouldmakeyourethinkthisstrategy.
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IfyoucanbackuptheentireVMandmountitsvirtualdiskdrivesoffline,youcaneasily restoreanycontentfromwithinthosediskdrives.Thisprocessiseasierandsimplerto workwith. However,beforeyoulookathowyouwillprotectasystem,youneedtoensurethat yoursystemrecoveryandprotectionstrategiesaresound.
UseStandardSystemRecoveryStrategies Everyorganization,largeandsmall,mustrelyonastandardsystemrecoverystrategy toprotecttheirmachines.Inavirtualinfrastructure,thismeansusingthesamestrategy forbothresourcepoolsandthevirtualmachinestheyrun.Standardrecoverystrategies shouldbebasedonthefollowingactivities:
▼ A serviceinterruptionisdetected.Thisinterruptioncanbeineithertheresource pooloraVM.IfitisinaVM,theimpactiscontainedtotheVMonly;butinthe resourcepool,theimpactcanaffectanynumberofVMsofferingservicesinthe productivitynetwork;therefore,reactionmustbeevenmoreprompt.
■ T heinterruptionmustbeinvestigatedandcategorized.Thebestwaytodothis istorelyonastandardtroubleshootingstrategy.
■ T helevelofriskmustbeevaluated.Thislevelofriskwilldeterminethe requiredlevelofresponse.Forexample,ifahostrunning20VMsfailsand thereisnoreplacementhost,responsemustbeimmediate.Ifthetroubleis withanoncriticalVM,theresponsecantakemoretime.
■ T herecoveryplanforthislevelofriskisputintoaction.Standardrecovery plansshouldalreadybeinplaceforthemostcommonsituations.These standardrecoveryplansshouldalsoincludea“PlanB”incasethemain recoverystrategydoesnotworkforsomereason.
■ Y ouperformtherecovery.Focusoncorerecoveryactivitiestogettheservice backupandrunningasfastaspossible.Oncethebasicrecoveryiscomplete, youshouldfullytesttheresultsoftherecoveryactionstoensurethat everythingisbacktonormal.
■ S econdaryrecoveryactionscanbeperformedoncethecoreactivitiesand testingarecomplete;forexample,brokenVMsthatweretakenofflineare repaired,orusersarenotifiedthattheirfilesarebackonline.
▲ O ncecomplete,theincidentshouldbedocumentedandproceduresare updated,ifrequired.
It is important to detail the actual recovery plan for each type of situation. This is one reasonwhyriskevaluationissoimportant.Youmaynothavetimetodocumentrecovery processes for every single disaster situation, but if you have taken the time to evaluate risks,youcanensurethatrecoveryplansforthemostcriticalsituationsaredocumented.In theend,youwillhavemultiplerecoveryplansthatwill“pluginto”yourrecoverystrategy.
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Alloftheseshouldbebasedonstandardoperatingprocedures(SOP)toensurethatyour staffrespondsinthesamemannertosimilarsituations. Inordertosupportthisrecoveryplan,you’llalsoneed:
▼ Anoffsitecopyoftheplantoprotecttheplanitself
■ Sparehardwarecomponentsonsitefortheresourcepool
■ Reliableandtestedsystembackups
■ Distancedoffsitestorageforrotatedbackupmedia,suchastape
▲ A vailableresources—systems,components,personnel—toperformsystems recovery
Inaddition,youneedtohaveeitherfailsafeserversorahotsite—aseparatesitethatmirrorsyourproductionsiteandthatcantakeoverinthecaseofadisaster—insupportof yourrecoveryplan.Hotsitescaneitherbeunderyourfullcontrolorhostedbyexternal serviceproviders,dependingontheresourcesyouhaveavailabletoyou.Moreonthis willbediscussedinChapter15.Asyouwillsee,withresourcepools,thissecondarysite iseasytosetup.
UseStandardTroubleshootingTechniques Acoreelementofthesystemrecoveryprocessisasoundtroubleshootingstrategy.This isthestrategyyouroperationsstaffshouldusetoidentifythetypeofdisastertheyare facing.Itisessentialthatthisstrategybeclear.Itshouldalsobeastandardwithinyour organizationbecausethisstrategyissocriticaltotherecoveryprocess.Forexample,if theissueyouarefacingiswronglyidentified,therecoverystrategyappliedtoitmay causeanevenworsedisaster.Youshouldapplythisstrategytobothresourcepoolsand VirtualServiceOfferings. In general, help requests and problem reports should be dealt with through an organized/scientific approach that treats system errors as always being causal; that is, problems don’t just happen—they are deviations from a norm that have distinct, identifiablecauses.Thetroubleshootingtechnician’sjobistologicallydeducecauses ofproblemsbasedonhisorherknowledgeofhowthesystemworks.Thebestwayto dothisistouseastandardprocedure. Forexample,yourtechnicianscouldrelyonthefollowingproceduretotroubleshoot systemissues:
1. O ncetheissueisdiscovered,documentappropriateinformation,suchasthe time,thedate,theaffectedmachine,andanyappropriateuserinformation.
2. D ocumentalloftherelevantinformationconcerningtheproblem.Referto yourbaselinesystemoperationinformationifnecessary.
3. Createanitemizedproblemdescription.Answerthesequestions:
■ Istheproblemreliablyreproducibleorrandom?
■ Isitrelatedtothetimeofday?
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■ Istheproblemuser-specific?
■ Isitplatform-specific?
■ Isitversion-specific?
■ Isitrelatedtoharddiskfreespace?
■ Isitnetworktraffic-related?
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4. R esearchsimilaroccurrencesinyourinternaltroubleshootingdatabases. Reviewthehelpsystemoftheaffectedcomponentifitisavailable.Also, reviewexternaltroubleshootingdatabases,suchasmanufacturerknowledge bases.Itisalsoagoodideatodrawontheexpertiseofyourcoworkers.
5. Createareasonablehypothesisbasedonalloftheavailableinformation.
6. Testthehypothesisanddocumenttheresults.
7. I fthetestsuccessfullycurestheproblem,documentandclosethecase.If unsuccessful,modifythehypothesisor,ifnecessary,createanewhypothesis. Repeatthehypothesisandtestcycleuntiltheissueisresolved.
Notethatcomplexproblems(morethanonecause-effectrelationship)mayrequireseveral iterationsofsteps2through7.RelyingonthisapproachwillgreatlysimplifyissueresolutionwheneveruntowardeventsoccurwithintheresourcepoolorwithinVMs.
CategorizeIssuesforResourcePoolsandVSOs One of the important aspects of troubleshooting is problem classification. It is often helpfultocategorizeerrorsaccordingtothecircumstancessurroundingtheoccurrence. Table14-1includesasamplelistofproblemclasses. Asyoucansee,yourtroubleshootingprocedureisnotonlyusedindisasters.Itcan beusedinalltroubleshootingsituations.Butfordisasters,thekeytothetroubleshootingandrecoverystrategyisthequalityofyourbackups—data,operatingsystem,and components.Thisiswhythebackupstrategyisoneofthemostimportantelementsof yoursystemresiliencyplan.
HypervisorManufacturerOfferings Backupstrategieswilldifferbasedonthehypervisoryourun.Eachhypervisorusesa completelydifferentapproach.Inaddition,approacheswilldifferbasedonthenumber ofhostserversyourunandtheirconfiguration.
VMwareConsolidatedBackup VMwareoffersaConsolidatedBackuptool,which,liketheUpdateManager,isavailable inalleditionsoftheVirtualInfrastructurebecauseitissuchacriticalcomponentofthe infrastructure.ConsolidatedBackupreliesonacentralizedproxyservertoperformand
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ProblemClasses
KeyCharacteristics
ResourcePoolsOnly Peripherals
Keyboard,videodisplay,hardwarecomponents, drivers
Network
Adapterconfiguration,traffic,cabling, transmissiondevices
ResourcePoolsandVirtualServiceOfferings Installation
Procedure,media,hardware/software requirements,networkerrors
Bootstrap
Missingfiles,hardwarefailures,bootmenu
Security
Fileencryption,accessrights,permissions
ServiceStartup
Dependentservices,configuration
Application
Application-specificerrors
Logon
Useraccounts,validatingserver,registry configuration,networkaccess
VirtualServiceOfferingsOnly UserConfiguration
Redirectedfolders,userprofiles,group memberships
Procedural
Usereducation,control
Table14-1. SampleProblemClassifications
runallbackupoperationsofboththeresourcepooldatabase(ifitiscontainedwithina VM)andtheVMsitruns(seeFigure14-1).Thekeytoitsoperationisthatbackupsare performed through the storage container, not through the local area network (LAN), whichiswhattraditionalbackupstrategiesdo.Becauseitprovidesanopenapplication programminginterface,ConsolidatedBackupwillintegratewithyourexistingbackup tooltoprovidecentralizedVMbackups. ConsolidatedBackupcanstreamtotapeordiskbyrelyingonsnapshotsoftheVMs yourun,whethertheyareonlineoroffline.Notehoweverthatitwillstreamtodiskfirst whenyouperformafullimagebackup.Whenabackupjobistriggered,Consolidated Backupcapturesthesnapshotandmountsittoperformthebackup,leavingtherunning VM on its original host and having minimal effect on its operation. Once the backup operationiscomplete,thesnapshotisdismountedanddiscarded.
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Figure14-1. VMwareConsolidatedBackupreliesonacentralproxyserverandthestorage containerfeatures.
ConsolidatedBackupalsosupportsfile-levelorincrementalbackupsaswellasfull image backups of the entire VM. Note that incremental backups are provided by the third-partybackuptoolyouusewithConsolidatedBackup.ConsolidatedBackupsupportsanytypeofstorage—storageaccessedthroughInternetSmallComputerSystems Interface(iSCSI),networkattachedstorage(NAS),storageareanetworks(SAN),oreven directattachedstorage(DAS). NOTE For a list of compatible backup software for VMware, go to www.vmware.com/pdf/vi35_ backup_guide.pdf.
CitrixXenServer CitrixdoesnotofferanyspecialtoolforeitherhostorVMbackups.Instead,Citrixrecommendsthathostsbekeptassimpleaspossibleintheirstructure.Ifahostfails,just reinstallitsincenodataislost.However,becauseeachhostserverstoresalocalcopyof theconfigurationdatabase,itisimportanttoprotectthisdatabaseatalltimesbecause ifyouloselocaldata,youstandachanceoflosingentireVMs.Theprotectionstrategies youwilluseforeachofthesedatabaseswilldependonthenumberofhostsyourun.
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Single hosts can be backed up through the command-line interface (CLI) for XenServer.Usethexepool-dump-databasecommandtoprotectthedatabaseonan individualserver.Usethexepool-restore-databasetorecoverit.Insomecases, youmayhavetorunthe xe vm-reset-powerstate commandtoensurethatthe stateoftheVMsonarestoredhostissettotheappropriatemode. Forserverpools,youmustprotectthemasterdatabasesincepooledhostsoperatein amaster-slaverelationshipforconfigurationdatabases.Youusethesamecommandsfor backingupandrestoringtheconfigurationdatabase,butyourunitonlyonthemaster server.However,therestorationprocedureisslightlydifferent.Becauseitisapool,you must also delete the old slave servers from the lost pool and re-create them. Run the xehost-forgetcommandtodeletetheoldslavesandthenrunthexepool-join commandoneachnewslavetojointhenewpool. Forvirtualmachines,CitrixrecommendsyoutreatthemasstandardphysicalmachinesandloadatraditionalbackupagentwithineachVM.RunVMbackupsjustthe wayyouusedtobeforeyoumovedtoavirtualinfrastructure. NOTE More information on XenServer backup strategies can be found at http://docs.xensource .com/XenServer/4.0.1/installation/apbs04.html.
MicrosoftHyper-V Since Hyper-V is a standard role that runs on Windows Server 2008, backup of both VMs—atleastWindowsVMs—andhostserversissimilartothestandardbackuppracticesyourunwithinanyWindowsnetwork.ThekeytoanybackupinWindowsServer, sinceversion2003,istheVolumeShadowCopyService(VSS).VSScantakeasnapshot of any running machine and then rely on this snapshot to perform the backup. VSS works with several backup providers, including Windows Server Backup (WSB), the newtoolinWindowsServer2008;Microsoft’sSystemCenterDataProtectionManager (DPM),astreamingbackupengine;andmostthird-partybackuptoolsthatworkwith WindowsServer. Basically, VSS acts like an orchestra conductor. It is the central actor that controls avolumeshadowcopyoperation.Todoso,itmustcommunicatewithalloftheother actorsintheprocess.Theprocessworksasfollows(seeFigure14-2):
1. A registeredrequestor—anapplicationthatisdesignedtoworkwiththe VolumeShadowCopyService,forexample,Hyper-V—beginsaVSSsession andrequeststhecreationofavolumeshadowcopy.
2. V SSsendsarequesttoallregisteredwriters—applicationsthataredesignedto understandVSSrequests—tofreezeallinputandoutput(I/O)activityonthe requestedvolume.
3. ThetargetedregisteredwriterindicatestoVSSwhenthisisdone.
4. O nceitreceivesconfirmationthatthefreezeisactive,VSSnotifiesthestorage providertoperformitsvendor-specificshadowcopyofthevolume.
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Figure14-2. ThevolumeshadowcopyprocessinWindowsServer
5. W hentheshadowcopyiscomplete,thestorageproviderconfirmstoVSSthat itisfinished.
6. V SSnotifiesthetargetedregisteredwriterthatitcanthawI/Oactivityonthe frozenvolumeandcontinuenormaloperations.
7. F inally,theVSSindicatestotheoriginalrequestorwhethertheoperationwas asuccessorafailure.
Thisprocessoccursextremelyfast.Infact,ifregisteredwritersaredesignedproperly,the processiscompletelytransparenttousers. AnotherimportantfactorintheVSSprocessisrelatedtothewaystoragetechnologies actuallycreatetheshadowcopy.Iftheycreatedanentirecopyofavolume,theywould requiresignificantphysicalspace.Thiscanbecomecost-prohibitive.Thisiswhymost storageprovidersprefertouseasingle-instancestoreapproach.Theydonotactually createacompletecopyofthedisk,butratherfocusonthechangestothevolumesince
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thelastshadowcopy.Microsoft’sproviderusesacopy-outprocessforthis:Everytimea diskblockistobeoverwritten,itismovedtoareservedareabeforethewriteoperation. Thisisasignificanttechnicalchallengethatcanleadtooverworkeddiskheads.Other providersuseamethodthatneveroverwritesthesamearea:Alloftheinformationis appendedtothedisk.Thismethodleadstolowercostsindiskspaceandismucheasier onthediskheads.Thisisthemethodusedbymosthypervisorstogeneratesnapshotsof theVMstheyrun. Asyoucansee,whenabackupoperationisrequested,Hyper-VinitiatesaVSSprocessandthebackupisrunoffthecopy.Copiescaneitherbediscardedorretainedasyou need.RetainingcopiesisagoodideasinceitallowsyoutorelyonthePreviousVersions clienttorestorelostfilesandfolders(seeFigure14-3).Youcanevenrelyonthistoolto recoverlostVMsonaHyper-Vhost.PreviousVersionsisafeatureofthepropertiesof afileinWindows.Simplyright-clicktheobject—fileorfolder—viewitsproperties,and thenmovetothePreviousVersionstabtorecoverthecontentyoulost.Thisisapowerful featureofthisoperatingsystemandonethatHyper-Vsimplyinheritssinceitrunson topoftheOS. NOTE For more information on the backup strategies for Windows Server 2008 (WS08), see Chapter 11 of Microsoft Windows Server 2008: The Complete Reference by Ruest and Ruest (McGraw-Hill,2008).
Figure14-3. UsingthePreviousVersionsclienttorestorelostdata
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WithSystemCenterDataProtectionManager,Microsoftoffersastreamingbackup enginethatwillcaptureremoteVSSimagesandstorethemcentrally,allowingadministratorstocentrallymanageallsnapshots.Theuser’sPreviousVersionsclientsareautomaticallyredirectedtothecentralVSSrepository,whichmakesitsimplertosupport. DPMstreamsallbackupstoacentraldisksystemandcanthenstorethemontapefor offlinestorage.ThisisamustformostorganizationssinceWindowsServerBackup,the toolintegratedwithWS08,nolongersupportstapeasabackupmedium.
DataProtectionStrategiesforHyper-VResourcePools BackingupHyper-Vhostserversmeansbackinguptwodifferenttypesofobjects.
▼ Operatingsystem ThepartitionthatmakesupdriveC:andrunsthe Hyper-Vrole.
▲ Datapartitions ThedatadrivethatcontainstheVirtualServiceOfferings. Thisshouldbesomeformofsharedorreplicatedstorage.
Hyper-VserversarethesimplestkindofserverinyourWindowsnetworkbecausethey onlyrunonemajorrole:virtualization.Ifyousetupyourinfrastructureright,backing upthesemachineswillberelativelyeasy.Ideally,eachandeverydrivethatmakesup theserverwillbehostedwithinthesharedstorageinfrastructure.Thisprovidesseveral levelsofdefenseagainstdataorsystemloss.
▼ E achpartitioncaneitherrelyontheVolumeShadowCopyServiceorthe internalsnapshottoolprovidedwiththestorageunittoprovideafirstline ofdefense.
■ T hesecondlineofdefenseisprovidedbythevolumeshadowcopyofthe virtualmachineslocatedonthedatadrive.
■ A thirdlineofdefenseisprovidedthroughreplicationofthefilesthatmakeup eachoftheVirtualServiceOfferings(VSOs).
■ Afourthlineofdefenseisprovidedthroughfailoverclustering.
▲ T helastlineofdefenseisprovidedthroughbackupsofthedisksthatmakeup eachhostsystem. CAUTION Youwillneedtoaddanotherdiskpartitiontoeachhostserverinordertoperformbackups through Windows Server Backup. WSB does not support backup to tape. Our recommendation: Obtain a third-party backup tool, since you will want comprehensive backup support for the host servers.GoodexamplesareSymantecBackupExec(www.symantec.com/backupexec/index.jsp)or CommVaultGalaxy(http://commvault.com/products/data_protection.asp).
Setupyourschedulestoprotectsystemsonanongoingbasis.Youshouldperform fullbackupsonceaweekandthenfollowwithdifferentialbackupseveryday.Differentialbackupstakeupmorespacethanincrementalbackups,buttheyareeasiertorecoverfrombecausetheyincludeallofthechangessincethefullbackup.Inarecovery
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situation,youonlyneedthemostrecentfullbackupandthemostrecentdifferential torestorethesystem.Thisisfasterthanusingincrementalbackupsbecauseyouneed toaddeachincrementaluntilthepointoffailuretorestoreasystem. IfyoudodecidetoperformhostsystembackupsfromWindowsServerBackup,use thefollowingcommandline.Itperformsafullsystembackuponceadayat6:00p.m.to adiskpartition. wbadminenablebackupaddtarget:DiskIDschedule:18:00user:Usernamepassword:Password
WhereDiskIDistheIDnumberofthedisktobackupto;usetheDISKPART,thenList DiskcommandstoidentifythediskID.UsernameandPasswordshouldbelongtoaserviceaccountwithlocaladministrationrightsonthehostserver. NOTE WhenyouuseWSB,destinationdrivesshouldbereservedexclusivelyforbackuppurposes becauseallotherdatawillbeerased.
DataProtectionStrategiesforVirtualServiceOfferings BackingupyourVirtualServiceOfferingswillmeanbackingupseveraltypesofinformation:userdata,corporatedata,databases,documents,systemstateinformationfor yourservers,andActiveDirectorydata.Asmentioned,youcanuseeitherthebuilt-in backuptoolorathird-partybackuptooltoperformthesebackups.Whicheveroneyou use, make sure that you will use a standard backup strategy, creating backup sets of specificdatatypes—forexample,creatingonlyuserdatabackupsinonebackupsetand onlysystemdatainanother.Thiswillsimplifytherestorationprocess. Data backups are rather straightforward; select the data drive and back it up. Rememberthatinmostcases,whetheryouuseWindowsorasharedstorageprovider, thebackuptoolwillautomaticallycreateasnapshotbeforebackingupthedataandthen createthebackupsetfromsnapshotdata.Thisavoidsissueswithopenfiles.Snapshot toolshavespecialapplicationprogramminginterfaces(APIs)thatenablethemtowork withdatabasessuchasActiveDirectory,SQLServer,andExchangeServer,makingthe snapshotsvalidevenfordatabases. Basically,youshouldbackupdataandoperatingsystemsonadailybasis.Performa fullbackuponceaweekandthenrelyondifferentials.Youneedtosupportyourbackup strategywithbotharemotestoragesolutionandoffsitemediastorage.Rememberthat you will need a third-party backup tool if you want to back up to tape on Windows Server2008machines.Youwillneedtoensurethatyouhaveasafeofflinestoragespace formedia.Youshouldrotateoffsitemediaonaregularbasis.Forexample,everysecond completebackupshouldbestoredoffsiteinacontrolledenvironment. Acommonschedulereliesonafour-weekretentionstrategy.Thismeansthatyou retainbackupmediaforaperiodoffourweeks.Ifyoukeepeverysecondcopyoffsite, youarealwaysonlyaweekawayfromcompletedisaster.Inaddition,yourarchiving schedulewilloutlinewhichcopiesyoushouldkeepoffsiteonapermanentbasis.
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RelyonReplicationforBackups IfyouareusingareplicationenginetoreplicateallofyourrunningVSOstoaremote site,youmaynotneedtofocusoninternalmachinebackups,sinceyoualreadyhaveoffsitecopiesofallofyourvirtualmachines.Intheeventofdataloss,youcanrelyonyour hypervisorenginetomountvirtualdiskdrivesinanofflinemode,lettingyourecover anydatafileyouneedfromthemountedvirtualharddrive. VMwaresupportsofflinediskmountingwiththeVirtualDiskManagerandthe DiskMount utilities. Both are found within the VMware Virtual Disk Development Kit at www.vmware.com/support/developer/vddk/VDDK-1.0-Relnotes.html. Use theVirtualDiskManagertoclone,create,relocate,rename,grow,shrink,ordefragmentofflinevirtualmachinedisk(VMDK)files.UsetheDiskMountutilitytomount anofflinediskinWindowsorLinuxandviewitscontentsasifitwereanotherdisk attached to your system. You can then recover the necessary files from within the offlinediskfile. Microsoft and Citrix can both rely on the Microsoft VHDMount tool, which is a Windows utility that mounts offline virtual hard disk (VHD) files and lets you view theircontentsasaseparatediskdrivefromwithinyoursystem.Findthisutilitywithin the Virtual Server 2005 R2 download at www.microsoft.com/windowsserversystem/ virtualserver.Theutilityiscontainedwithinthedownloadandmustbeextractedfrom ittouseitonitsown. NOTE FollowtheseinstructionsfromChrisWolf,oneofourtechnicalreviewers,toextractVHDMount without installing Virtual Server: http://myitforum.com/cs2/blogs/rcrumbaker/archive/2007/06/13/ vhd-mount.aspx. UsingthisstrategywouldgreatlysimplifyyourVSObackupandrestorestrategies. Make sure, however, that the replication tool you use is virtual machine–aware and understands the makeup of VMs to ensure proper data replication. More on this is coveredinChapter15.
SelectaThird-PartyBackupTool In many cases, organizations will opt to rely on a third-party backup tool to protect theirenvironments.VMwarerecommendstheuseofathird-partytool;Citrixabsolutely requires a third-party tool; and Microsoft’s new Windows Server Backup is not an enterprise-class backup tool. Because of this, you will most likely find yourself in a situationwhereyouneedathird-partytool,ifyoudon’talreadyhaveone. Oneofthemostimportantaspectsoftheselectionofathird-partybackuptoolisits awarenessofthecomponentsthatmakeahypervisoroperate.Manybackuptoolsare notdesignedtointeractproperlywiththehypervisoryourunand,therefore,willnot understandthemake-upofvirtualmachinefiles.Whenyouchooseabackuptool,make sureitishypervisor-aware.
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Anumberofthird-partybackupsolutionsonthemarketarespecificallydesignedfor hypervisors.Theyallmeetspecificcriteria,whichmustinclude:
▼ Beingawareoftheinnerworkingsofthehypervisor
■ Beingabletoprotectcentralizedmanagementdatabasedata
■ B eingintegratedwiththesnapshotserviceofyourstorageprovider,triggering asnapshotbeforelaunchingabackupoperation
■ B eingabletoworkwitheitherWindowsorLinuxvirtualmachines,depending ontheinfrastructureyouruninyourVSOs
■ Enablingcompletehostsystemrecoveryfromasimpleprocess
▲ Enablingcompletevirtualmachinerecoveryfromasimpleprocess
Meetingthesebasiccriteriaisessential.Thereareothercriteria,ofcourse,suchasintegratingwithmassivestorageproductsthataresupportedbyyourhypervisorengine, including special drivers for SQL Server, Exchange,Active Directory, Oracle, and so on; but the ones listed here are the core requirements for an intelligent, third-party backupsolution. NOTE Onegoodwaytoproceedistorelyonyourhypervisorvendor’srecommendationforthevery bestbackuptoolselection.Eachmanufacturerliststhird-partytoolsthatworkwiththeirengines.For VMware,gotowwwa.vmware.com/partnercatalog/catalogandselectISVSystemInfrastructureand theBackupandAvailabilitySoftwaresubcategory.ForCitrix,gotowww.citrix.com/English/partners/ partnertop.asp?ntref=hp_nav_US.ForMicrosoft,gotowww.windowsservercatalog.comandlookfor InfrastructureSolutions,thentheHyper-Vsubcategory.
COMPLETETHERECOVERYSTRATEGY Protectingdatawithinthevirtualinfrastructuremeansadaptingtraditionalapproaches tothenewrequirementscreatedbythesegregationoftheresourcepoolandtheVirtual Service Offerings. Securing these environments also requires adapting your methods. Overall,you’llfindthatbecauseyounowhavetwoinfrastructures,you’llhavetoadapt othermanagementmethodsaswell.This,alongwithsystemredundancystrategies,is thetopicofthenextchapter. Beprepared.Securing,protecting,andmanagingvirtualinfrastructuresisdifferent thanworkingwithphysicalinfrastructuresalone.Ifyourorganizationislargeenough, youmaybeabletodedicateresourcestoeachinfrastructure;butifnot,you’llhavetotrain yourself and your colleagues to wear different hats and respond in different manners whenissuesarise.
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V
irtualization transforms the way organizations run their datacenter. Server virtualization transforms productivity workloads into malleable engines that canberunwhenneededandscaledbasedonbusinessrequirements.Desktop virtualization lets you create volatile or stateless desktop operating system images that can greatly simplify management and reduce the pains of distributed desktop administration. Application virtualization finally gives you the ability to defeat DLL Hellonceandforallandprovideuserswithanapplication-on-demandmodel.Profile virtualizationletsyourusersuseanydesktopanywherewithinyourorganization. Alloftheselevelsofvirtualizationfinallyletyoubuildthedynamicdatacenter—a datacenterthatcanadjustitselfdynamicallytobusinessfluctuations.Butthisdatacenter doesnotbuilditselfonitsown.Sofar,you’veseenhowallofthedifferentlevelsofvirtualizationcanimpactyourdatacenter;butinordertorunvirtualizationandmakethebest ofit,youhavetwoitemslefttocover:businesscontinuityandmanagementpractices. Businesscontinuityfocusesonmakingsurethatyourservicesarealwaysavailableat alltimes,whereveryouareandwhereveryouneedthem.TosupportthisnewITmodel, managementpracticesmustbeupdatedandmustbesupportedbytheappropriatetoolset.ThesemanagementchangesarecoveredinChapter16.
BUSINESSCONTINUITYESSENTIALS Systemredundancyreliesontheimplementationofmethodsandmeasuresthatensure thatifacomponentfails,itsfunctionwillimmediatelybetakenoverbyanotheror,at theveryleast,theproceduretoputthecomponentbackonlineiswelldocumentedand wellknownbysystemoperators.Someofthemostcommonadministratorheadachesare networksecurityanddisasterrecovery.It’snotsurprising.We’veallfaceddisasters,such as9/11andHurricaneKatrina,andweallknowjusthowdamagingtheseeventscanbe tobusinessesofanysize.Infact,avastmajorityofbusinessesthatdonothaveabusiness continuityplaninplaceandfaceamajordisasteroftengoundersincetheycannotrecover fromsuchcatastrophicevents.Theseissuesareattheverycoreofanynetworkdesign. Nomatterwhatyoudo,youmustensurethatyoursystemsareprotectedatalltimes. Once again, the Castle Defense System can help. Layer 1 helps you identify risk levelsbecauseithelpsyoudeterminethevalueofaninformationasset.Riskisdeterminedbyidentifyingvalue(theimportanceofanasset)andmultiplyingitbytherisk factorthatisassociatedwithit.Theformulalookslikethis: Risk=assetvalue*riskfactor
Forexample,anassetthatisvaluedat$1millionwithariskfactorof0.2hasariskvalue of$200,000.Thismeansthatyoucaninvestupto$200,000toprotectthisassetandreduce itsriskfactor. Whilethesecalculationscanbeesotericinnature,whatremainsimportantistoinvestthemostintheprotectionofyourmostvaluedassets.Thisisonereasonwhyitisso importanttoknowwhatyouhave.Figure15-1isagoodreminderofthisprinciple. Chapter3introducedtheconceptofavirtualinfrastructurearchitecture(seeFigure15-2). Thisarchitecturefocusedonthesevenlayersofvirtualizationandhowyouprotectthem.
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Figure15-2. Thesevenlayersofthevirtualarchitecture
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Inaddition,itcoveredhoweachofthetwonetworksyourunshouldbecontainedwithin differentsecuritycontexts.Nowyouneedtocompletethisarchitectureandaddressthe elementswhichwillensurethateachcriticalcomponentofthisarchitectureisprotected andavailableatalltimes. To ensure availability of each piece of the infrastructure, you must address the requirementsofeachlevelofthearchitecture.Thisincludesthefollowing:
▼ T heresourcepoolmustincludeprotectionforeachelementoftheserver virtualizationinfrastructure.Thismustfocusonthehostserversandthe storageinfrastructurethatsupportsthem.
■ V irtualServiceOfferingsmustalsobeprotectedthroughthecapabilitiesofthe infrastructureyourunforthem.
■ V irtualdesktopsmustbesetuptoprotecttheiravailability,especiallythe abilityofuserstoreconnecttotheirdesktopswhenevertheyneedto.
■ A pplicationrepositoriesmustbemadehighlyavailabletoensurethat applicationsrunallthetime.
■ P rofilestoragecontainersmustalsobeavailableatalltimesandprotected throughbackups,asdiscussedinChapter14.
■ T heallocationandmanagementlayersmustbeupdatedtoincludenewways ofdoingthingsinIT.
▲ T heentireinfrastructuremustbeprotectedthroughoffsitereplicationand otherbusinesscontinuitypractices.
Protecting each resource and ensuring its availability will allow you to complete the entirevirtualizationarchitectureandrunITinresponsetoyourorganization’sbusiness imperatives.
MaketheResourcePoolHighlyAvailable Byfocusingonphysicalprotection,orprotectionoftheresourcepool,Layer2oftheCastle DefenseSystemalsohelpsyouplanforsystemredundancy.Buthostserversarenotthe onlycomponentintheresourcepool.AsoutlinedinChapter14,theresourcepoolcontains severaldifferentelements,eachofwhichmustincludesomelevelofprotectiontoensure itisrunningandavailableatalltimesandthatsystemoutagesormaintenancewindows cannotleaveyououtinthecoldwhenyouneedtoaccessafeatureoftheresourcepool. Thismeansthatyoumustprovideprotectionforeachofthefollowingelements:
▼ Hostservers Theseserversmustbemaderedundant,whethertheyare centralizedorinremotelocations.
■ Storagecontainers Thesemustnotbecomesinglepointsoffailure.
■ M anagementdatabase Thisdatabasecontainscriticaloperationalinformation andmustbeavailableatalltimes.
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■ M anagementvirtualmachines(VMs) Thesemachinesprovideaccesstothe managementdatabaseandcontroltheresourcepoolhosts.Forthisreason,they mustbemaderedundant.
■ M anagementdesktopvirtualmachines(DVMs) Thevirtualdesktopsthat operatorsusetoaccessthemanagementinfrastructuremustbeprotectedat alltimes.
■ R esourcepoolActiveDirectory Thisdirectorymusthavebuilt-inredundancy tobecomehighlyavailable.
▲ Additionalservers Anyadditionalserveryouincludeintheinfrastructure mustbemadehighlyavailable.Forexample,iftheyarerequired,youmay havetorunlicensingserverstosupportyourimplementation.Also,iftheyare inuse,thecertificateserversyouruninsupportofencryptedcommunications mustbeprotected.Thesamewouldgoforanyotherinfrastructureelement youmaintainfortheresourcepool—NetworkAccessProtection,Virtual PrivateNetwork,UpdateServices,andsoon.
Protectingtheresourcepoolmeansprotectingeachoftheseelements(seeFigure15-3).
CreateHighlyAvailableHostServers As you know, for your resource pool to work and your Virtual Service Offerings to remainavailableatalltimes,youmustintegratehigh-availabilityconceptsandcomponentsineachhostserver.Beginwiththeconstructionoftheserveritself.RandomArrays of Inexpensive Disks (RAID) and teamed network cards, for example, provide direct hardware-level protection for a host system. However, the ideal host system includes anintegratedhypervisorandwillnotrequirelocaldiskdrives;ifyoumustrunahost operatingsystem,runitfromsharedstorage,notlocaldisks. Itisalsoimportanttoincludeuninterruptedpowersupply(UPS)systems;thesecan either be individual USB–connected UPS devices (for regional servers), or centralized powermanagementinfrastructuresthatprotectentirecomputerrooms(usuallyatcentralsites). Resourcepoolsalsoneedredundancy.Eachoneofthephysicalserversplayinghost toaVirtualServiceOffering(VSO)musthavesomeformofredundancybuiltin.Ifahost serverisrunning10to15VSOs,itmustbeabletofailovertheseVSOstoanotherphysicalhostintheeventofafailureatthehardwarelevel.Thismeansthephysicalhostsmust beclustered—sharingtheVSOworkloadsothatVSOsareavailabletousersatalltimes. ThisisonereasonwhyitissoimportanttohostVSOsonsharedstorage.Becausethey arehostedonastoragestructurethateachhostserverhasaccessto,VSOscanbemoved fromhosttohostwithlittleimpactonusers.Thisprovidessite-levelredundancy.This alsomeansthatyoumusthavemorethanonehosttosupportvirtualworkloadfailover. Rememberthegoldenrule:Ifyouperformaphysicalconsolidationof20servers,you willnothavea20-to-1consolidationratio;rather,youwillhavea10-to-1consolidation ratiosinceyoumusthavetwohoststosupporthighavailabilityofthe20virtualservers (seeFigure15-4).
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Figure15-3. Protectingtheresourcepool
Figure15-4. Toprovidesite-levelredundancy,youmustalwayshavesparehosts.
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VMware relies on the Virtual Machine File System (VMFS) and the HighAvailability feature to provide this level of availability. Citrix XenServer relies on the resource pool concept along with shared storage. Microsoft, because Hyper-V runs onWindows,reliesontheWindowsServerFailoverClusteringfeaturealongwith,of course,sharedstorage. Site-level redundancy is also necessary at the regional level if you choose to host virtualworkloadsinremotelocationstoprovidebetterserviceavailability.Thisiswhy the ideal regional server will be an all-in-one box that includes at least two physical hostservers,sharedstorage,andwideareanetworkconnectivity.Byincludingtwohost servers,youcanmakesuretheregionalVSOsthisinfrastructurehostswillalwaysbe available(seeFigure15-5).
ProtectStorageContainers When you build for high availability, you must ensure that no single component can becomeapointoffailure.Thismeansthateachandeverycomponentmusthavesome redundancybuiltintoit.Forexample,youcan’tplaceallofyourvirtualworkloadsinto asinglesharedstoragecontainer,becauseifitfails,you’llhaveevenmoreproblemsthan withasinglehostserverfailurebecauseallofyourvirtualmachineswillfail.
Figure15-5. Useall-in-oneboxestoprovideregionalsite-levelredundancy.
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StoragecontainerswillalsoincludeRAIDconfigurationstoprovideafirstlevelof defenseagainstfailure.Theyalsocontainseveralfeaturesthatletyousnapshotcontents so that you can protect them through backups. In addition, many storage containers, especially storage area networks (SANs), will include the ability to replicate contents fromoneSANstructuretoanother. Severalhostsystemscantakeadvantageofthisreplicationenginewhilerunningwithin the same site. VMware provides this feature through Storage VMotion, a tool that will automaticallymovethecontentsofaVMfromonestoragecontainertoanotherwithout failure(seeFigure15-6).Ofcourse,youmuststructuretheSANaccordingtoVMware’s guidelinesforStorageVMotiontowork.Thissolutionisasite-levelsolutiononly. NOTE VMwarepublishesinformationonhowtoconfigureSANswithitstechnologythroughthe VMware SAN System Design and Deployment Guide at www.vmware.com/pdf/vi3_san_design_ deploy.pdf. MicrosoftcanusemultisitefailoverclusteringtodothesamethingwithitsHyper-V engine.WindowsServer2008supportstheabilitytocreateaclusterthatdoesnotrelyon sharedstorage,butcanactuallyrelyondirectattachedstorage(DAS).Thisclusterwill
Figure15-6. VMwarecanmoveaVMfromonecontainertoanotherwithStorageVMotion.
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providefailoverforthevirtualmachinesitruns—not,ofcourse,throughlivemigration, but through the Quick Migration feature, which pauses the machine, transfers it, and thenrestartsit.Thisfailoverwillnotrelyonashareddiskinfrastructure,butwillrequire datareplicationthroughathird-partyenginebetweeneachofthehostsinthecluster. ClusterdataisstoredonaFileShareWitnesstoensurethateachhostisawareofthestatusofothers.Thisisamajority-node-setclusterstructureinWindows.Thisclusterstructureisdesignedtoprovidemultisitefailover,runningaclusternodeindifferentsites, butthereisnoreasonwhyyoucannotusethisstructuretoprovidesingle-sitefailoveras wellasstoragecontainerprotectionatthesametime(seeFigure15-7). NOTE FormoreinformationonmultisiteclusteringwithWindowsServer2008,gotowww.microsoft .com/windowsserver2008/en/us/clustering-multisite.aspx. For a step-by-step guide on clustering Hyper-V,gotohttp://technet.microsoft.com/en-us/library/cc732181.aspx. CitrixXenServerreliesonthird-partyproductstoprovidethistypeofprotection.Citrix partners Steel Eye (www.steeleye.com), LeftHand Networks (www.lefthandnetworks .com),andotherssuchasMarathonTechnologies(www.marathon.com)providetools thatprotectbothdataandthehostineitherasingleormultiplesites. Other storage vendors, such as NetApp, provide replication capabilities for networkattachedstorage(NAS)aswellasSANs.NetAppreliesonthesamestrategyas VMwareforsystemsmanagement.VMwarealwaysreliesonVirtualCenterformanagementoftheirvirtualinfrastructure,addingfunctionalitytothetoolasyougrow. NetAppdoesthesame,addingfunctionalitytoitsstoragemanagementengineasyou growwithoutdifferentiatingbetweenNASorSANofferings.Thisgreatlysimplifies theuseoftheirproducts.
Figure15-7. Usingamultisiteclustertoprovidesite-levelprotectionfordisksandhosts
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ProtecttheManagementVMsandDVMs AsdiscussedinChapter14,theresourcepoolisnotonlymadeupofphysicalmachines. Infact,itoftencontainsseveralvirtualmachines.Thesemachinescanplayanynumber ofroles.
▼ Runthevirtualizationmanagementsoftware.
■ R unadesktopoperatingsystem(OS)tosupportadministrativeaccesstothe resourcepoolmanagementVMs.
■ R untheActiveDirectory,whichsynchronizessecuritygroupswiththeroles youassignintheresourcepool.
■ R unthedatabaseengine(local,SQLServer,orOracle),whichcontains managementdata.
▲ P ossiblyrunadditionalroles,suchascertificateservices,NetworkAccess Protection,VirtualPrivateNetwork,andsoon.
WhileitispossibletorunmanyoftheserolesonthesameVM,itmakessensetouseat leasttwoVMsandpossiblyevenmorethanthattoensurethehighavailabilityofthe servicesthatmaketheresourcepoolrun.Usetheseguidelinestocreateahighlyavailableresourcepoolinfrastructure:
▼ A sabestpractice,runatleasttwomachinesforActiveDirectory.Keepthese machinesseparatefromotherroles.Thesemachinesshouldalsorunthe DomainNameService(DNS)rolesinceActiveDirectoryrequiresDNSto operate.Whileitispossibletorunmultipleservicesonadomaincontroller, itisnotrecommendedsincethisisahighlysecurerole.Itmaybeokaytorun morethanoneserviceontheseserverssincetheydonotinteractwithend users,onlywithadministrators,operators,andtechnicians.Determineyour needbasedonyouravailablebudget.
■ R unatleasttwomachinesforthedatabaseengine.Thesemachinescanrun otherservices—forexample,theresourcepoolmanagementtool—butthey mustbeclusteredtomakesurethatthemanagementdatabaseishighly available.ForSQLServer,thismeansrunningtheWindowsFailoverCluster Service(WFCS)intheVMsthathostthedatabase.ForOracle,thismeans runningRealApplicationClusters(RAC).Becauseofthis,itmaynotbepossible torunthevirtualizationmanagementtoolonthesameserverinstances. CAUTION Oracledoesnotsupportitsapplicationswhentheyarerunningonanyhypervisorother thanOracleVM.
NOTE XenServer does not require this server role since it uses a master/slave configuration repositoryoneachhostserver.
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■ I fyouseparatethehostmanagementtoolfromthedatabase,runatleasttwo instancesofthisserviceontwodifferentVMs.SettheVMstoautostartwhen thehostserverbootstoensureyouhaveimmediateaccesstohostmanagement whentheresourcepoolisrunning. NOTE As a best practice, you should set each of the VMs that is part of the resource pool administrationinfrastructuretoautostart.Thisway,youhaveimmediateaccesstoallofthetoolsthat supportresourcepooloperations.
■ R undesktopVMswiththemanagementclienttoconnecttotheresourcepool managementVMs.Asabestpractice,itisalwaysbesttoaccessmanagement toolsthroughadesktopratherthanthroughaserver.Makethesedesktop VMspartoftheresourcepoolActiveDirectory(AD).UsingDVMswilllet administrators,operators,andtechniciansconnecttotheresourcepoolfrom theirproductiondesktopsoranyotherconnectedsystem.Theylaunchthe virtualdesktop,logintotheresourcepoolAD,andaccessthemanagementtool throughacompletelyseparatesecuritycontext,protectingtheinfrastructure fromtheirproductionnetwork.
▲ R unadditionalservicesfromotherVMs.ServicessuchasCertificateServices willrequireatleasttwoVMs:onethatisoffline—therootcertificateauthority (CA)—andonethatisonline—theissuingCA.Thesemachines,especiallythe offlinemachine,shouldnotbedomaincontrollers.VirtualPrivateNetwork (VPN),NetworkAccessProtection(NAP),andUpdateServicescouldbe cohostedonthesameservers.Youdonotwantthemtobecohostedonthe managementVMsbecauseVPNserversareoftenthepointofentryinto anetworkfromoutsideyourzoneofinfluence.Ifsomeonecompromises theVPNserveranditiscohostedonthemanagementserver,thiscould compromiseyourresourcepool.
Manyoftheseservices,excepttheobviousWindowsservices,canrunonLinuxaswell asWindows.However,rememberthattheWindowsServerEnterpriseEditionlicense grantsyoutherighttorunuptofourfreeinstancesofWindowsinvirtualmachines.If youdothisright,youcanruntheentireinfrastructureinfewerthaneightVMs,keeping yourWindowslicensingcostsdown. Building redundancy in your systems is valuable only if you know it works. It’s not enough to be prepared; you need to know that your preparation has value. To do so, you’ll need to test and retest every single redundancy level you implement in yourresourcepool.Toomanyorganizationshavemadethefatalerrorofputtinghighavailabilitytechnologiesinplacewithouttestingthem,onlytofindoutthattheydidn’t workwhentheyneededthem.Thisisnotamyth.Itactuallyhappens.Don’tletithappen to you. Test all your systems and document your procedures. In fact, this is another excellentopportunityforyoutowritestandardoperatingprocedures.
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ProtectYourVirtualServiceOfferings Buildingaredundantnetworktosupporttheresourcepoolispartofthehigh-availability structureyouneedtoputinplace.Youalsohavetomakesurethattheservicesyouoffer withinyourproductivitynetworkarehighlyavailable.Whilesomethinkthatyoudon’t needtoworryaboutthisifyouhavetherightvirtualinfrastructureinplace,itisstill goodpracticetodoso. Take,forexample,anExchangeserverrunninginaVM.Thisserverisrunningas astand-aloneservice.SinceitisinaVM,itwillbemadehighlyavailablebecausethe resourcepoolishighlyavailable.IfthehostserverrunningtheVMfails,theVMwill automaticallybemovedtoanotherhostthroughHighAvailability(HA)features.There will,however,beaminorinterruptioninservicebecauseHAisnotlikelivemigration; sincethereisafailureatthehardwarelevel,alloftheVMsrunningonthishostwillalso failbeforethehypervisor’sHAfeaturedetectsthehostfailure.Oncethehostfailureis detected,themachinesaremovedandrestarted. ButwhathappensifthefailureisintheVM,notonthehost?Inthiscase,hypervisortechnologiesofferalotoffeaturesthatarenotavailableonphysicalmachines. For example, you can restart the Exchange VM from a snapshot or from an older offlinecopy,butthiswouldmeanlosingsomedata.Youre-mailuserswon’tbetoo happyaboutthat. Theansweristoclusterwithinthevirtualizationlayer.Ifyou’rerunningWindows, youcanruneitherFailoverClusteringorNetworkLoadBalancing(NLB)onthevirtual machines. If you’re running Linux, you’ll want to implement enterprise clustering to maketheworkloadshighlyavailable.Then,ifaservicefailsforanyreason—hostserver failure,VMfailure,andsoon—itwillautomaticallyfailovertoanotherVMinyournetworkandwon’tcauseaserviceinterruptionforyourendusers.
ConsiderHighAvailabilityforDifferentServices Clusteringisnottheonlyformofhighavailabilityyoucanrun.Manyservicesinclude built-inreliabilityfeatures.Considerthefollowing:
▼ Directoryservices Resiliencyhereiscreatedthroughthedistributionof directoryserversthroughoutyournetwork.Itisalsobasedonmultimaster replicationsystemsandthecreationofanappropriatereplicationtopology.
■ D NS DNSisoftenmarriedtoadirectoryservice.ByintegratingDNSwith thedirectoryservice,youensurethatyournetworknameresolutionservice willalwaysfunctionbecauseithasthesameresiliencyasthedirectoryservice. ThisfeatureisprovidedthroughDNSreplication.
■ D HCP Youraddressallocationinfrastructurealsohasresiliencebuiltin becauseofthewayyoustructureditwithredundantscopes.Inaddition,if youplaceyourDynamicHostConfigurationProtocol(DHCP)serversin differentsites,youhaveasolutionthatwouldcontinuetoworkintheevent ofadisaster.
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■ F ileshares Yourfilesharescanbemaderesilientthroughvariousfeatures oftheoperatingsystemyourunonthem.Forexample,Windowsincludesthe DistributedFileSystem(DFS),whichcancopyfilesharecontentsfromonesite toanother,makingthemresilient.DFSalsosupportsautomaticfailover—i.e., iftheservicefailsinonesite,itautomaticallyfailsoveruserconnectionstothe othersite.DFScanalsobeprotectedthroughfailoverclusters.
▲ Volumesnapshots Yoursharedfiles,shareddatabases,Exchangestores,and othersharedinformationrepositoriesarealsoprotectedthroughthesnapshot feature,eitherinyourOSoryourstoragecontainer.Forexample,inWindows, theVolumeShadowCopyServicecantakesystemsnapshotsonaregularbasis andevenallowenduserstorecoverfilesthemselves.
Theseareonlyafewexamplesofbuilt-inresiliencyfeatures.Butdespitethefactthat several of your systems are resilient, there remain areas that could have significant impactonyouroperationsiftheyfailed. Remember,oneofthemainreasonsforhackerattacksisDistributedDenialofService orDDoS.Thistypeofattackcansucceedfortworeasons.First,theserverhostingthe serviceisnotprotected,andsecond,theserviceishostedbyasingleserver,i.e.,thereisno failoverservice.Chapter14showedyouhowtoprotectyoursystemsthroughtheCastle DefenseSystem.NowyouneedtoaddadditionalresiliencytotheVSOnetwork.
ClusterServicesforVirtualServiceOfferings Whilemanyservicesincludetheirownbuilt-inresiliency,othersmustrelyontheresilient features of the OS they run on. As mentioned earlier, for Windows, this is Failover ClusteringandNLB.Todeterminewhichtousewhen,keepthefollowinginmind:
▼ W henprotectingstatelesssystemsorsystemsthatprovideread-onlyservices, relyonNetworkLoadBalancing.
▲ W henprotectingstatefulsystemsorsystemsthatprovideread-writeservices, relyonFailoverClustering.
It’sasimpleformula:SystemsthatdonotpersistdatarelyonNLB.Thesesystemsare usuallyfront-endsystems.SystemsthatpersistdatarelyonFailoverClustering.These systemsareusuallyback-endsystems. NLBclustersdonotneedanyparticularhardwaresincetheyrelyonnetworkinterface cards to work. Failover clusters, however, rely on either Small Computer System Interface(SCSI)emulationorInternetSmallComputerSystemInterface(iSCSI)connectors.FailoverClusteringalsoworkswithFibreChannel,butthereisnoFibreChannel emulationinthevirtualizationlayer,atleastnotyet.InWindowsServer2008,youcan createeither2-nodeorupto16-nodeclusterswithFailoverClustering.NLBsupportsup to32nodesinacluster. You’llfindthatclusteringinVSOswillbemorecomprehensivethaninresourcepools becausethereismoretoprotect.Table15-1outlinesthefeaturesandsupportedservices foreachclusteringmodeforVSOsinWindowsServer2008(WS08).
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ClusteringService
NetworkLoadBalancing
FailoverClusters
WS08edition
Web Standard Enterprise Datacenter
Enterprise Datacenter
Numberofnodes
Upto32
Upto16
Resources
Minimumoftwo networkadapters
SCSIoriSCSI diskconnectors Minimumoftwo networkadapters
ServerRole
ApplicationServers(stateless) DedicatedWebServers CollaborationServers (front-end) TerminalServers(front-end)
Application
WebFarms InternetSecurityand AccelerationServer(ISA) VirtualPrivate Network(VPN)Servers StreamingMediaServers UnifiedCommunications Servers
ApplicationServers (stateful) FileandPrintServers CollaborationServers (storage) NetworkInfrastructure Servers SQLServers ExchangeServers MessageQueuingServers FileServers PrintServers
Table15-1. WS08ClusteringServices
Asyoucansee,NLBandfailoverclustersarerathercomplementary.Infact,itisnot recommendedtoactivatebothservicesonthesameserver;thatis,afailoverclustershould notalsobeamemberofanNLBcluster.Inaddition,NLBclustersaredesignedtosupportmorestaticconnections.Thismeansthattheyarenotdesignedtoprovidethesame typeoffailoverasaservercluster.Inthelatter,ifauseriseditingafileandtheserver stops responding, the failover component will automatically be activated and the user willcontinuetoperformhisorherworkwithoutbeingawareofthefailure(theremaybe aslightdelayinresponsetime).Thisisbecausetheserverclusterisdesignedtoprovide amirroredsystemtotheuser.ButanNLBclusterwillnotprovidethesametypeofuser experience.Itsmainpurposeistoredirectdemandtoavailableresources.Assuch,these resourcesmustbestaticinnature,sinceNLBdoesnotincludeanycapabilityformirroring informationdeposits.
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Bothclusteringservicesoffertheabilitytosupportfourservice-offeringrequirements.
▼ Availability Byprovidingserviceofferingsthroughacluster,itispossible toensurethattheyareavailableduringthetimeperiodstheorganizationhas decreedtheyshouldbe.
■ R eliability Withacluster,itispossibletoensurethatuserscandependon theserviceoffering,becauseifacomponentfails,itisautomaticallyreplaced byanotherworkingcomponent.
■ S calability Withacluster,itispossibletoincreasethenumberofservers providingtheserviceofferingwithoutaffectingtheservicebeingdelivered tousers.
▲ Maintenance AclusterallowsITpersonneltoupgrade,modify,applyservice packs,andotherwisemaintainclustercomponentsindividuallywithout affectingtheservicelevelofserviceofferingsdeliveredbythecluster.
AnadvantagethatfailoverclustershaveoverNLBclustersistheabilitytosharedata. Failoverclusterresourcesmustbetiedtothesamedatastorageresource,ensuringthe transparencyofthefailoverprocess. Clustersdohavedisadvantages.Theyaremorecomplextostageandmanagethan stand-aloneservers,andservicesthatareassignedtoclustersmustbecluster-awarein ordertotakeadvantageoftheclusteringfeature. CAUTION Remember that if you create a highly available configuration for a Virtual Service Offering,youmustensurethatanti-affinityruleshavebeenappliedtotheVMswithintheresource pool.Anti-affinityruleswillensurethatthevirtualmachinesthatmakeupahighlyavailableservicewill notresideonthesamehostandwillbedistributedamongavailablehosts.Afterall,ifthetwonodesof anExchangeclusterrunonthesamehostandthathostfails,bothnodeswillfailandallyourefforts towardscreatingahighlyavailableExchangeservicewillhavebeenfornaught.
WindowsVSOClusterCompatibilityList Ifyou’rerunningWindowsserviceswithinyourVSO,asmostorganizationsdo,you’ll wanttoknowhowtoprotecteachserviceyourunintheproductivitynetwork.Evenin Microsoft’sownproductoffering,therearesomeparticularitiesintermsofclustering compatibility.Clustercompatibilitycanfallintooneoffourcategories:
▼ WSFC-awareisaproductorinternalWS08servicethatcantakefulladvantage oftheclusterservice.Itcancommunicatewiththeclusterapplication programminginterface(API)toreceivestatusandnotificationfromtheserver cluster.Itcanreacttoclusterevents.
■ W SFC-independent(orunaware)isaproductorinternalWS08servicethat isnotawareofthepresenceoftheclusterbutthatcanbeinstalledonacluster andwillbehavethesamewayasifitwereonasingleserver.Itrespondsonly tothemostbasicclusterevents.
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■ W FSC-incompatibleisaproductorinternalWS08servicethatdoesnotbehave wellinthecontextofaclusterandshouldnotbeinstalledonaservercluster.
▲ NLB-compatiblelistsproductsthatarewellsuitedtoNLBclusters.NLBand WSFCareoftenincompatiblewitheachother.
Table15-2categorizesMicrosoft’sWindowsServerSystemandWS08functionsinterms ofclustercompatibility.
ProductorService
WSFC- WSFC- WSFC- NLB- Aware Independent Incompatible Compatible Comment
ActiveDirectory DomainServices (ADDS)
X
Notrecommended; availabilityisprovided throughmultimaster replication.
ActiveDirectory Lightweight DirectoryServices (ADLDS)
X
Notrecommended; availabilityisprovided throughADLDS replication.
BizTalkServer
X
X
X
BizTalkstateserver andmessagebox arecluster-aware. Messagingand processingserversare cluster-independent. Allotherservices shoulduseaNetwork LoadBalancing cluster. BizTalkcanalso takeadvantageofa clusteredSQLServer back-end.
COM+
X
CommerceServer
DFS
Componentload balancingclusters preferred. X
X
Table15-2. WindowsVSOClusterCompatibilityList
Componentload balancingclusters preferred. Stand-aloneDFS namespacesonly.
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WSFC- WSFC- WSFC- NLB- Aware Independent Incompatible Compatible Comment DomainDFS namespacesuse redundancy providedbyADDS. AlsosupportsDFS replication.
DHCP-WINS
X
Fullycompliant.
Distributed Transaction Coordinator
X
Fullycompliant.
DNS
X
Exchange2000 andlater
X
FileServer
X
Redundancyprovided byADDSwhen integratedwiththe directory. X
Fullycompliant. InExchange2007, differentserverroles cantakeadvantageof differentmodes. Fullycompliant.
Generic Application
X
Supportsnon-cluster– awareapplications throughcustom integration.
GenericScript
X
Supportsnon-cluster– awarescriptsthrough customintegration
GenericService
X
Supportsclusterindependentservices throughcustom integration.
Hyper-V
IIS ISAServer
X
Whilenotrunina VSO,theHyper-V roleismostdefinitely cluster-aware. X X
X
NLBclustersare preferred.
X
NLBclustersare preferred.
Table15-2. WindowsVSOClusterCompatibilityList(continued)
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ProductorService
WSFC- WSFC- WSFC- NLB- Aware Independent Incompatible Compatible Comment
InternetStorage NameService (iSNS)Server
X
Fullycompliant.
MicrosoftIdentity LifecycleManager
X
Fullycompliant.
Microsoft MessageQueuing
X
Fullycompliant.
NetworkFile System
X
TheWindowsNFS engineiscompletely cluster-aware. X
OfficeLive Communications Server(LCS)
OfficeProject Server
X
X
LCSisincompatible withWFSC.Usean NLBclusterforfrontendservers.Usea WFSCforSQLServer back-ends. OnlytheSQLServer portion.
OfficeSharePoint PortalServer
X
X
OnlytheSQLServer portion. TheIISportionshould useNLB.
OtherServer
X
WSFCsupports cluster-independent serverrolesthrough customintegration.
PrintServer
X
Fullycompliant.
SQLServer2000 andlater
X
Fullycompliant.
SystemCenter Configuration Manager
X
SQLServerback-ends canbeclusteredunder specialconditions. X
SystemCenter Operations Manager TerminalServices SessionBroker
X
Table15-2. WindowsVSOClusterCompatibilityList(continued)
Notsupported.
Fullycompliant.Also usedtosupportvirtual machineconnections.
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WSFC- WSFC- WSFC- NLB- Aware Independent Incompatible Compatible Comment X
WindowsServer UpdateServices
Windows SharePoint Services
X
Windows StreamingMedia
X
Notsupported.
X
Front-endservers canbeload-balanced; however,WSUSonly updatessystems onceamonthand maynotrequirea highlyavailable infrastructure.
X
OnlytheSQLServer portion. TheIISportionshould useNLB.
X
NLBclustersare preferred.
Table15-2. WindowsVSOClusterCompatibilityList(continued)
TheinformationinTable15-2issubjecttochangeaseachoftheproductsevolves,but itservesasagoodstartingpointindetermininghowyoucanconfigurehighavailability foryourservices. NOTE Asservervirtualizationevolves,Microsoftserverproductteamsarerefiningthesupported high availability strategies for their particular product. For example, Exchange 2007 is now only supportedwhenhighavailabilityisappliedattheguestOSlevelandnotatthehostlevel.Formoreon thispolicysee:http://technet.microsoft.com/en-us/library/cc794548.aspx.
MakeVirtualDesktopsHighlyAvailable Chapter10outlinedhowcentralizeddesktopvirtualizationworkedandhowitfitinto yourservervirtualizationinfrastructure.Themajordifferencebetweentheresourcepool forservervirtualizationandtheresourcepoolfordesktopvirtualizationisthatforthe first time, security boundaries are crossed. This is due to how desktop virtualization actuallyworks.Theprocessworkslikethis(seeFigure15-8):
1. T heuserturnsonhisorherpoint-of-accessdevice.Thiscanbeaworkstation, personalcomputerathome,thinclientdevice,orevenapublicbrowser.Then, theusergoestothevirtualdesktopinfrastructure(VDI)interfaceandlogson.
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2. T heproductionActiveDirectoryverifiestheuser’scredentialsand,iftheyare valid,logsthemon.
3. T ogether,theActiveDirectoryandthedesktopbrokerassignthedesktop virtualmachinetobeused.
4. T heprovisioningengineassignsthedesktopvirtualmachine(DVM)toahost withintheservervirtualizationinfrastructure.
5. T heloginprocessbegins,andthevirtualizedapplicationiconsappearonthe user’sdesktop.Theuser’sremoteprofileisalsoloaded.
6. O ncetheuserhasfinishedworkandlogsoffofthesession,theDVMis discardedbecausethecoreDVMimageisread-only.
7. T heDVMthengoesbacktothepool,andallchangedinformationintheuser profileissavedintheuserprofilestore.
Thisprocessisrelativelysimple,butitrequiresthoughtandpreparationtosetupand workproperly.
Figure15-8. Thedesktopvirtualizationassignmentprocess
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However,theDVMassignmentprocessoutlinesafewkeyitemsthataredifferent fromtheservervirtualizationinfrastructure.
▼ F irst,instepfouroftheDVMassignmentprocess,thereisanoperationthat crossessecurityboundaries.Thisisbecausethedesktopbrokersendsasignal totheprovisioningenginetoassigntheDVMtoahostserver.Inthisparticular operation,theprovisioningengine,whichiscontainedwithintheproduction ActiveDirectory,mustinteractwiththeresourcepoolbecauseitneedsaccess rightstoassigntheDVMtoahostserver.Thisinteractionisusuallyperformed byembeddingthecredentialsrequiredfortheoperationwithinthecommand thatissent.Forthisreason,thelinkbetweentheprovisioningserverandthe resourcepoolmustbeencrypted.
■ S econd,thisoperationrequiresseveralsupportingcomponents,includinga repositoryforAppVapplications,arepositoryforuserprofiles,astreaming engineforAppVapplications,theDHCPtoassignvolatileInternetProtocol (IP)addressestoDVMs,ActiveDirectory,DNS,andmuchmore.Eachofthese componentsmustberenderedhighlyavailabletosupportDVMassignments.
▲ M anyoftheitemsrequiredtomaketheDVMassignmentprocessoperate shouldalreadybeinplaceinmostWindowsnetworks.
This means that the DVM architecture must be a mix of resource pool and Virtual ServiceOfferingcomponents(seeFigure15-9).YoumustkeepinmindthatanyinteractionsbetweentheVSOandtheresourcepoolinfrastructuresmustalwaysbehighly securedandprotected.
ProtectDVMAssignmentInfrastructureComponents Whileyourservervirtualizationinfrastructureisalreadywellprotected,severalcomponentsofthedesktopvirtualizationinfrastructurehavenotbeenaddressedyet.These includethefollowingitems:
▼ TheproductionActiveDirectory
■ TheproductionDNS
■ TheDHCPservice
■ T hefile-sharingstoresthatcontainapplicationvirtualization(AppV) applicationsandprofiles
■ TheAppVstreamingengine
■ T hevirtualdesktopinfrastructurecomponents,suchasthedesktopbrokerand theprovisioningserver
■ Thevirtualdesktopsthemselves
▲ Optionally,filesharereplicationandabstractionengines
Eachcomponentrequiresdiscussion.BothAppVandprofileprotectionmechanismsare discussedlater,buttheothercomponentsmustbeaddressedhere.
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Figure15-9. DVMassignmentinfrastructurecomponents
TheproductionActiveDirectoryisusedforseveralitems.Itlinksuseraccountswith assigneddesktops,providesthedesktopswithsecurityidentifiers,appliesGroupPolicy to the desktops and to users, and assignsAppV applications to users. Group Policy especially is the core engine that will control roaming user profiles and folder redirectionsettings,makingprofilevirtualizationworkalongwithdesktopvirtualization.
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Basically,anyproductionActiveDirectory(AD)musthaveatleasttwodomaincontrollersforeachdomainitcontains.Normally,productionADsruninamultidomainforest,protectingtherootoftheforestfromend-userinteraction.Thismeansaminimum offourdomaincontrollersandpossiblymore.ADstructuresfocusonboththelogical (structureoftheorganizationalunitswithineachdomain)andthephysical(structure ofthesitescontainedwithintheforesttocontrolreplication).MakesureyourADstructuresaresoundandreadyforprimetime. NOTE ForadiscussiononproductionActiveDirectorystructures,downloadthefreeChapter3 fromWindows Server 2003, Best Practices for Enterprise Deployments at www.reso-net.com/livre .asp?p=main&b=winsvr&m=12.This chapter covers each aspect of a production Active Directory structure. DNSisalsoakeycomponentoftheDVMinfrastructureforseveralreasons.DNSis atthecoreoftheoperationoftheproductionActiveDirectory.Assuch,itshouldnormallybeintegrateddirectlywiththedirectory.Thebestwaytodothisistomarrythe DNSrolewitheachandeverydomaincontrollerinyournetwork.DNSisalsocriticalfor theoperationoftheDVMs.SinceeachDVMisvolatile,itwillbeassignedavolatileIP address.ThisaddressmustberegisteredinDNSfortheDVMtoworkproperly.Using aWindowsDNSserverintegratedwithADandwiththeWindowsDHCPservicewill ensuretheproperoperationoftheDVMs. DHCPisalsoarequirement.ADHCPserverisusedtoassignvolatileordynamic IPaddressestomachinesasthemachinesstartupwithinaproductionenvironment.In addition,theWindowsDHCPserverwillautomaticallyinteractwiththeWindowsDNS servicetoensurethateachmachineisproperlyregistered.ModernWindowsoperating systemswillmanagetheirownregistrationwithinDNSoncetheyreceivetheIPaddress fromtheDHCPserver.TomakeaDHCPinfrastructureresilient,youmusthaveatleast twoDHCPserversintheproductionnetworkandeachDHCPservermustbeconfigured tosupport50percentoftheaddresseswithinthisnetwork. The VDI components must also be highly available. The high-availability solution willvary,dependingontheVDIengineyouuse.Insomecases,boththedesktopbroker andtheprovisioningservercanbemadehighlyavailablebyinstallingmorethanone copy of the service and running them against a load balancer. The load balancer you usewillgreatlydependontheVDIproductyouuse;butbasically,theprocessusesan IPaddresstranslationscheme,whichredirectsTransmissionControlProtocol/Internet Protocol (TCP/IP) requests to available servers. This is similar to the Network Load Balancingservicediscussedearlier,andwhilesomeproductswillrunwithNLB,others requirethird-partyloadbalancingappliancestorun. Inothercases,theVDIcomponentswillincludetheirowncapabilityforhighavailability.Forexample,CitrixXenDesktopprovidesbuilt-inhighavailabilityforeachof itscomponents.AXenDesktopfarmconsistsofmultipleDesktopDeliveryControllers (DDCs), which include a DDC master and multiple DDC member servers.If a DDC master becomes unavailable, a DDC member will automatically be promoted as the newmaster.Inaddition,apooledvirtualdesktopenvironmentwilluseProvisioning ServertobootDVMsthroughthePre-bootExecutionEnvironment(PXE)capabilities
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ofnetworkinterfacecards.Forhighavailability,ProvisioningServerwillensurethat PXEbootrequestsfromDVMsarehandledinatransparentmannerbyload-balancing requestsacrossmultipleservers. DVMsmustalsobeprotectedtoensurethattheyarealwaysavailable.ForaDVMto workproperly,itmustcommunicatewiththedesktopbroker.DVMsdiscoverdesktop brokersthroughthelinktoActiveDirectory.Ifmultipledesktopbrokerserversareavailable,theDVMwillpickoneatrandom,makingithighlyavailable. Finally,thelastcomponentistheprotectionofthefilesharesthathostbothvirtual applicationsanduserprofilecontents.Virtualapplicationsharescanberead-onlysince usersystemsonlyreadthecontentstoruntheapplications.Profileshares,ontheother hand,mustbereadandwrite.WindowsServerincludesapowerfultoolcalledtheDistributed File System (DFS). DFS is made up of two components. The first is the DFS namespace (DFSN).A DFS namespace is used to create one single namespace for file shares with multiple targets. DFS namespaces use the Universal Naming Convention (UNC)filesharingformat,butinsteadofusinga\\servername\sharenameformat,they use a \\domainname\sharename format. The namespace uses one single name, but multipletargets.Thisallowsittobeavailableinmultiplesites.Usingmultiplefileshare targetsmakesyourfilesharesredundant.DFSnamespacesintegratewithActiveDirectorytomakesureusersalwaysfindtheappropriatetargetwherevertheyare. ForDFSnamespacestoworkproperly,theymustcontainthesameitems.Thisiswhy the second DFS component, DFS replication (DFSR), must be used in conjunction with thenamespace.DFSRisadeltacompressionreplicationenginethatwillreplicateonlythe changesmadetoafileatthebytelevelandcompressthembeforesendingthemoverWAN links.Inaddition,DFSRcancontroltheamountofbandwidthusedforreplication,letting youcontrolexactlyhowreplicationwillruninyournetwork.UsingDFSNswithDFSR will make sure your applications are always available locally in remote sites and your userswillalwaysfindtheirprofiles,wherevertheyareinyournetwork. NOTE FormorecompleteinstructionsonbuildingandconfiguringeachoftheseWindowsServer componentsinsupportofVDIhighavailability,seeMicrosoftWindowsServer2008:TheComplete ReferencebyRuestandRuest(McGraw-Hill,2008). Makingsureeachoftheseitemsishighlyavailablewillensurethatyouruserswill always find their centralized desktops, wherever your users are and whenever they needthem.
MakeVirtualApplicationsHighlyAvailable AsdiscussedinChapter11,applicationvirtualizationbringsmajorchangestotheway youworkwithapplications.SeveralcomponentsarerequiredtomakeAppVwork,many ofwhichhavealreadybeenmadehighlyavailablethroughtheVDIyouprepared.
▼ ActiveDirectoryisusedtoassignAppVapplicationstoendusers.
■ F ilesharesareusedastheAppVrepository.TheyshouldberunningwithDFS, shouldyourequiretherepositoryinmorethanonesite.
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■ S treamingserversshouldbeusedtomaketheapplicationsavailablewithinthe virtualdesktopsyourun.
■ M anagementserversallowyoutoassignapplicationsandlinkthemtoAD securitygroups.
■ DatabaseserversareusedtostoreAppVassignmentinformation.
▲ A ppVpackagingandadministrationstationsareusedtocreatetheAppV packagesandadministertheAppVinfrastructure.Thesemachinescansimply bevolatileDVMswithAppVcomponents.
ThemajordifferencebetweentheAppVinfrastructureandtheVDIinfrastructureisthat theAppVinfrastructuredoesnotneedtointeractwiththeresourcepoolatanylevelbecausevirtualizedapplicationsareend-userapplications—atleastfornow—anddonot runonservers.Eveniftheydid,youwouldmostlikelyassignAppVservertoolstothe productionnetworkratherthantotheresourcepoolnetwork. OfallofthecomponentsrequiredtomakeAppVwork(seeFigure15-10),Active Directory,fileshares,andtheNLBcomponentsthatmakethestreamingservershighly available have already been dealt with. The database servers should run the same Failover Clustering service as the database engines for the resource pool. However, thesedatabaseserversarelocatedwithintheproductionnetwork,nottheresourcepool, andmaysupportotherinfrastructuremanagementdatabases,suchastheonesrequired forUpdateServices,inventory,orthetraditionalElectronicSoftwareDistribution(ESD) engineyouusetomanageutilitiesandcomponentsthatcannotbevirtualized.
Figure15-10. AhighlyavailableAppVinfrastructure
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Thepackagingworkstations,ifpreparedproperly,cansimplybevolatiledesktop VMs and because of this, will be made highly available through the components of yourVDI.
MakeProfilesHighlyAvailable AsseeninChapter11,profilevirtualizationissupportedthroughamixtureofroaming profilesandfolderredirection.RoamingprofilesareassignedinActiveDirectorysince theyareanattributeoftheuser’saccount.However,roamingprofilesalonearemonolithicandcantakealongtimetoload.Byremovingcontentsfromtheroamingprofile andassigningthemtoredirectedfolders—bothofwhicharedonethroughGroupPolicy settings—youcanensurethattheroamingprofileremainssmallandloadsfast. Contentssuchastheuser’sdocuments,whicharemadeavailablethroughfolder redirection,arethenavailableondemand.Redirectedfoldersarenetworkfileshares and, because of this, do not need to download contents into the volatile desktop as theuserlogsin.Whenauseropensaredirecteddocument,thedocumentisopened fromthefileshareandautomaticallycachedwithinthedesktopmachine.Onceitis cachedlocally,accessisevenfaster.Ifchangesaremadeofflineforsomereason,the SynchronizationManagerinWindowswillautomaticallysynchthecontentsfromthe localcachetothenetwork. Components that support profile virtualization have already been addressed throughboththeVDIandtheAppVinfrastructures.ActiveDirectoryisalreadyhighly availableandthefilesharesshouldberunningDFSNandDFSR,especiallyifremote sitesaresupported.ThemajordifferencebetweenaprofilefileshareandanAppVfile shareisthattheAppVfileshareisread-onlyforusers,whiletheprofilefileshareisset toread-writeforendusers. Making the VDI, AppV, and profile virtualization infrastructures highly available will ensure that no matter what happens at the site level, your end users will always haveaccesstotheircentralizeddesktop.
BUILDYOURBUSINESSCONTINUITYSTRATEGY All of the preparations to date have had one single aim: make your services and infrastructureshighlyavailableatthesinglesitelevel.However,thisdoesnothingwhen somethinggoeswrongandtheentiresiteisnolongeravailable.Thiscanbecausedby anynumberofpotentialdisasters. Therearetwotypesofdisasters:naturalandmanmade.Naturaldisastersinclude earthquakes,tornados,fires,floods,hurricanes,landslides,andmore.Theyarehard to predict and even harder, but not impossible, to prevent. The best way to prevent thesedisastersistohaveredundantsites:Yourcoreserversandservicesareavailable atmorethanonesite.Ifyourmaindatacenterisimpairedforanyreason,yourother sitetakesover.Thisisalsowheretheconceptofthefailsafeservercomesintoplay.This server is a standby server that is dormant, but can be activated quickly if required.
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Inthedynamicdatacenter,thismeansprovidingredundantresourcepoolserversand savingcopiesofeachoftheVSOsyouruninproduction. Therearealsomanmadedisasters:terroristattacks,powerfailures,applicationfailures, hardware failures, security attacks, and internal sabotage. These attacks are also hardtopredict.Somerequirethesametypeofprotectionasfornaturaldisasters.Others, suchasapplicationandhardwarefailuresandsecurityattacks,canbeavoidedthrough theCastleDefenseSystem. Todeterminethelevelofserviceprotectionyouneedtoapply,youcanuseaservice categorizationthatissimilartotheLayer1categorizationfordata.
▼ Mission-criticalsystems Thesearesystemsthatrequirethemostprotection becauseinterruptionofserviceisunacceptable.
■ M ission-supportsystems Theserequirelessprotectionthanmission-critical systems,butinterruptionsshouldbeminimizedasmuchaspossible.
■ B usiness-criticalsystems Thesearesystemswhereshortservice interruptionscanbeacceptable.
▲ Extraneoussystems Thesearedeemednoncriticalandcanhavelongerlastinginterruptions.
Whatmostpeopleseldomrealizeisthatthebasicnetworkinfrastructureforyournetwork is, in many cases, part of the mission-critical level because if it does not work, nothingworks. BecauseVMsarenothingbutasetoffilesonaserversomewhere,youcanensurea betterbusinesscontinuitymanagement(BCM)practice.Asseenearlier,alocalBCMis ensuredthroughhigh-availabilitymeasures.Forexample,allhostserversareconnected toasharedstorage.Ifahostserverhasanoutage,thehighavailabilityautomatically shifts the load to another node in the cluster, but you must have spare nodes in each cluster.Toprotectagainstsite-leveldisasters,youmustimplementamultisiteBCM.And becausevirtualmachinesarenothingbutasetoffilesonaserver,you’llfindthatthe multisiteBCMismucheasiertoimplementthaneverbefore.
ProvideMultisiteRedundancy Site-levelredundancyisnolongersufficientfororganizations.Toomanyorganizations literally lose everything when disaster strikes.You don’t want all of your eggs in the samebasket.Fortunately,theadventofvirtualizationmakesitmucheasiertoprovide multisite redundancy. First, you need to build a second datacenter, if it isn’t already available.Thissecondarydatacenterdoesnotneedtohostthesameresourcesasyour productionenvironment(seeFigure15-11).Itjustneedsamodicumofresources—just enough,infact,tohelpyougetbackonyourfeetinthecaseofanemergency.Thismeans itrequiresafewhostserversattachedtosharedstorage.ItalsoneedscentralpowerprotectiondevicesandWANconnectivity.
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Figure15-11. Providingmultisiteredundancy
This secondary site could even be hosted by an Internet service provider (ISP). Severalareavailableonthemarket.UsinganISPmightbethebestchoiceforsmall andmediumbusinesses,becausesettingupasecondarydatacenterforthepurposeof businesscontinuitymanagementisacomplexandsometimesexpensiveventure. NOTE Several ISPs offer this service, for example SunGard (www.availability.sungard.com), Sunrad (www.sanrad.com/products/overview.aspx), and INetU (www.inetu.net/innovative-support/ virtualization.php).Chooseyourprovidercarefullyandlooktotheirprivacyagreementstoensurethat yourdataissecurewhenhostedoutsideyourorganization.
AdjustYourServiceLevelAgreements Servicelevelagreements(SLAs)fordisasterrecoveryarenotthesameasthosefornormalproduction.Whenadisasteroccurs,youwillneedtobeginwithessentialservices only.Inaddition,whenyouareinadisasterrecoverysituation,itshouldnotlastforever, butonlyforthetimeyouneedtogetbackonyourfeet.Becauseofthis,thehostserver resourcesyouneedinthedisasterrecoverysitearenotthesameasthoseinyourproductiondatacenter. Youcanrelyonaformulatohelpyoudeterminejusthowmanyphysicalresources yourdisasterrecoverycenterwillrequire.Theformulalookslikethis: ProductionResources/RecoveryTime=DisasterRecoveryResources
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Forexample,ifyouarerunningyourinfrastructureon15physicalhostsandyouexpect yourrecoverytimetobethreehours,youcanrunthedisasterrecoverycenterwithfive physicalhosts.Thelowertherecoverytime,themoreresourcesyouwillneedtopopulateyourrecoverycenter. Balancethenumberofphysicalresourcesinyourrecoverycenterwiththeneedto reload critical services. In the event of a disaster, your recovery will require essential servicesfirst—forexample,ActiveDirectoryDomainServicesandDNS—thenloadsecondaryservices,DHCP,fileandprintservers,andsoon.Usingagraduatedapproach forthereloadingofservicesforuserswillletyoubringeverythingbackonlineinstages andwillreducetheoverheadcostofthesecondarydatacenter.
BusinessContinuityManagementThroughReplication Remotebusinesscontinuityforresourcepoolsisprovidedthroughdatareplicationtechnologiesthatwillreplicatethecontentsofyourstoragecontainersfromonelocationto another.Youcanrelyonthestoragecontainer’sownreplicationengineoryoumayusea third-partyengine.Theadvantageofusingathird-partyreplicationengineisthatitoften includesthecomponentsyouneedtoredirecttheservicesyourendusersareaccessingto theremotesiteintheeventofadisaster.Thissimplifiesthedisasterrecoveryprocess. Eachresourcepoolvendorreliesonadifferentsolutionformultisiteresiliency.For example,MicrosoftcanrelyonthemultisiteFailoverClustermentionedearliertomake Hyper-Vmultisite-resilient(seeFigure15-12).Thissolutionreliesonthebuilt-infeatures ofWindowsServer2008,butalsorequiresathird-partyreplicationenginetomaintain storagecontentsthatareidenticalbetweenthesites.Notethatforthissolutiontowork, youmusthavetheexactsameresourcesavailableinboththeproductionandtheremote sites.Thisnegatesanycost-effectivenessforthissolution. NOTE For a list of supported replication partners for Hyper-V Failover Clustering, go to www .microsoft.com/windowsserver2008/en/us/clustering-multisite.aspx.
Figure15-12. UsingmultisiteFailoverClusteringwithHyper-V
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Citrix relies on third-party products for business continuity. Basically, you must obtainareplicationengineforaXenServerresourcepool.Theenginewillincludethe capabilitytoperformcontinuousdataprotection(CDP)throughreplication,aswellas theabilitytoredirectalluserstoaremotesiteintheeventofafailure.Redirectionis mostlyperformedthroughchangesintheDNSentriesforeachoftheservicesusers relyon. VMware relies on Site Recovery Manager (SRM) as well as integrated SAN capabilitiesorreplicationenginestoprovidemultisiteredundancy.SiteRecoveryManager isacomponentoftheVMwarevirtualinfrastructurethathelpsyoubuild,manage,and executedisasterrecoveryplans.SRMensuresthatrecoverieswillbereliablebyenabling nondisruptivetesting.Italsoeliminatesmanualrecoverystepsthroughautomation,and providescentralizedmanagementofrecoveryplans(seeFigure15-13). SRMprovidesasimpleintegratedinterfacethatis,onceagain,anextensionofthe capabilities of VMware Virtual Center (see Figure 15-14). This greatly simplifies the administrationofthetoolsinceyoualwaysworkwiththesameinterface. SRMfullysupportsthedatacenterreplicationmodeldiscussedearlier.Recoveryor secondarysitesdonotneedtohavethesameoridenticalresourcesastheproductionor primarysite.Forexample,ifyourproductionsitereliesonaSANusingFibreChannel andtheverybesthigh-speeddrives,yourrecoverydatacentercaneasilyruniSCSIon
Figure15-13. RunningVMwareSiteRecoveryManager
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Figure15-14. TheVMwareSiteRecoveryManagerinterface
SerialATA(SATA)drives.Thismeansthattherecoverysiteismuchcheapertoputin placethantheproductionsite.Relyontheformulaoutlinedearliertodeterminejust whichkindsoftechnologiesyouwillwanttoputinplaceintherecoverysite. NOTE For more information on VMware Site Recovery Manager, go to www.vmware.com/ products/srm.
ChoosetheProperReplicationTool The replication tool you select must be able to fully understand the make-up of your virtualmachinesandvirtualizationenginetoworkproperly.SeveralSAN-basedreplicationtoolsareonlycapableofreplicationandnothingelse.Sincereplicationoccursatthe
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bytelevel,thecontentofthedatadoesn’treallymatter.However,considerthefollowing whenyouselectyourreplicationengine:
▼ Theenginemustbeofficiallysupportedbythevirtualizationvendor.
■ T heenginemustbeabletoworkwithanyofthestorageinfrastructuresyou putinplace:DAS,NAS,orSAN.
■ T heenginemustsupportautomaticfailoverofresources,properlyredirecting enduserstotheremotelocation.
▲ Theenginemustsupportisolatedrecoverytesting(seeFigure15-15).
The last item is probably one of the most important since replication alone does not make a recovery solution. With VMware, as discussed earlier, Site Recovery Manager willperformmanyofthekeyactivitiesrequiredtorecoverfromasite-baseddisaster.But ifyouarenotrunningVMware,you’llneedsimilarcapabilities.Thesewillcomefrom yourreplicationtooloracombinationofyourreplicationtoolandthebuilt-infeatures ofyourhypervisor. Ifyoucan’ttestafailoversituationwithoutdisruptingyourproductionnetwork, you’llhavetotaketheproductionnetworkdowntoperformthetest.Nottestingis notasolution.Ifyoudonottestyourfailoverstrategies,youwillneverknowifyour solutionworks.Don’twaituntilamajorfailureoccurstofindoutthatnothingworks asyouexpected!
Figure15-15. Performingisolatedrecoverytesting
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Also,whilepreviousphysicalnetworksreliedonreplicationtechnologiestoprovide availabilityofaservice,younolongerneedtobeconcernedaboutthisinaresourcepool. Forexample,severalreplicationvendorshavemadesmallfortunesprotectingMicrosoft Exchangethroughreplicationengines.Inthepast,youwouldimplementareplication engine to ensure that should the Exchange server in one location go down, another duplicateExchangeserverwouldspringbackupelsewhere.Withresourcepools,you donotneedtoworryaboutthisbecauseifyoureplicatetheVMrunningExchangeand theVMcanbebroughtbackupelsewhere,that’sallyouneed.Don’treplicateinsidethe VMs—only focus on replicating the resource pool contents and your solution will be adequate. Finally,rememberthatreplicationisnotabackupsolution;itisaBCMsolution.But ifyouhavetheproperBCMsolutioninplace,itmayactasanadditionallevelofprotectionforvirtualmachinecontents.
PrepareforSite-BasedDisasters Whenplanningforyourremotebusinesscontinuitymanagementsite,keepthefollowingitemsinmind.InBCMsituations,youmust:
▼ Beginwithcriticalservicesfirst:domaincontrollers,DNS,DHCP
■ T henlaunchcriticalapplications:businessapplications,e-mailservices,and soon
▲ R uninreducedservicelevelagreementmode—notallservicesarerequiredin theBCMsituation
Because of this, you can start with just enough hardware to get core VMs going and tokeepyourbusinessrunning.IftheBCMsituationlastslonger,provisionmorehost serversandlaunchadditionalvirtualworkloads.Ifyouuseintegratedhypervisors,they willbeeasytoaddtotheBCMresourcepool. Usethefollowingruleofthumb:Startwith25percentofyourproductionhardware capacity. Identify all of your critical applications. Assign a priority to each of these applications.Thenruncontinuousteststoensurethatallcriticalapplicationswillload withthisBCMconfiguration.Adjustyourconfigurationasnecessary.Finally,makesure youdocumentyourBCMstrategycompletelyandthatalladministratorsandtechnicians areawareofit.Disastersdon’tonlyhappentomachines;theyhappentopeopleaswell. Makingsureyourentireteamknowswhattodoinadisastersituationwillgoalongway towardsprotectingyourbaseswhentheworsthappens.
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ast,butnotleast,you’llhavetoreviewyourmanagementpractices.Thismeans lookingtonewadministrativeandtechnicalrolesyourstaffwillplayintheresource poolinfrastructure.Italsomeansworkingwithnewpolicy-basedworkloadsor workloads that dynamically boot up when required in support of business processes. Resource pool management will also force you to look at new ways to do things in branchoffices.Inaddition,theywillmoveyoutocreateanewdivisionofresponsibilities betweenresourcepoolsandproductionnetworks. Tomakesureyouhavefullcontroloverthetwoinfrastructuresyourun,you’llneed tomakesureyouhavetherightmanagementtoolsinplace.Willyouusethesametools foreachinfrastructure,orwillyousegregatethetwo?Thesequestionswillhelpyoucompletethereflectionyoumustundertaketomovetoacompletelyvirtualinfrastructure.
LOOKTONEWADMINISTRATIVEROLES Managingtwoinfrastructures,physicalandvirtual,changesthewayITneedstowork within the datacenter. This is evident in the tools you use to manage your resource pool.Forexample,inVMwareVirtualCenter,theAdministrationtabincludesdefault resourcepoolroles(seeFigure16-1).Whileyoudon’tneedtorelyoneachoftheseroles, someadditionalrolesarerequired.Table16-1outlinessomeoftheneworchangedroles you will find in a datacenter that virtualizes servers, desktops, and applications and mapsthemtotheappropriateinfrastructure. The roles outlined in Table 16-1 cover both networks. For example, the server virtualizationrolesallresideintheresourcepoolonly,butthedesktopandapplication virtualizationrolesallresidewithintheproductivityorvirtualnetwork. Rememberthattheserolesdonotneedtohaveaspecificbodyattachedtothem. Larger organizations will probably have personnel to fill each role, but smaller and medium-sizedorganizationswillprobablyrelyonafewpeopletofillalloftheroles. Inthelattercase,personnelwillhavetowearmultiplehatstomakesureeverything getsdone.
MOVETOPOLICY-BASEDWORKLOADS One of the biggest impacts virtualization has on IT operations is the ability to create policy-basedworkloads.Inavirtualinfrastructure,physicalserversarenothingbutresourcesthatarepooledtogethertocreateawhole,muchlikethenetworkinfrastructure. Productivityserviceofferings—theofferingsthatinteractwiththeusers—arerunning invirtualmachinesonly.Becausetheseservicesareallofferedatthevirtuallayer,they becomemuchmoremalleablethaneverbefore. While no organization could afford to have multiple physical servers that just sit therewaitingforabusinessneed,everyorganizationcanaffordtodothiswithvirtual machines. Let’s say you have a pressing need for temporary services in support of a seasonalbusinessfluctuation.Inyesterday’sITworld,youwouldhavetoplanforthis workloadfluctuationwellaheadoftimetoensureyoucouldruntheadditionalservices
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Figure16-1. DefaultadministrativeroleswithinVMwareVirtualCenter
yourequireforit.Buttoday,youcansimplycreateworkloadson-the-fly,addingthemto yourinfrastructureasneeded—provided,ofcourse,youhavetherequiredhostservers torunthem. This ability to create machines when needed, run them, and then remove them is partoftheautomationthatisrequiredinthevirtualdatacenter.EachVMhasalifecycle, as discussed in Chapter 9, and this life cycle includes steps that might not have been addressedorwerenotrequiredinthepast.Machinesarecreatedasneededandrunon onehostoranotherbasedonthepoliciesandprioritiesyousetforthemachine.While itismucheasiertocreateVMson-the-fly,itisalsoeasytoletthemlingerwhennotin use.SeveralVMsareoften“atrest”waitingforsomeonetousethembutstillconsumingspaceandresources.Thisisonereasonwhyitisoftenbettertocreatetime-based machinesthatwillautomaticallybereturnedtotheVMpoolwhentheirpurposehas beencompleted.
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VirtualizationType
Role
Description
Server Virtualization
ResourcePool Administrator
Hasfullaccesstotheresourcepool andallofthetoolsitcontains. Includescontrolofthedesktop virtualizationinfrastructureaswell.
ResourcePool Operator
Hasfullaccesstoservervirtualization controlswithintheresourcepool.
ResourcePool Technician
Installsnewhostservers,creates newvirtualmachines(VMs),stages newvirtualworkloads,updatesVMs andhosts.
ResourcePoolUser
Testingordevelopmentrolethat supportstheuseofspecificvirtual machines.
ResourcePoolReader
Letsmanagementviewthestatus oftheresourcepoolandthevirtual machinesitruns.
DesktopOperator
Hasfullaccesstodesktopvirtualization controlswithintheresourcepool. Managesdesktopvirtualmachine (DVM)groupswithinthepool.
DesktopTechnician
CreatesnewDVMs,stagesnew virtualDVMimages,updatesDVMs.
DesktopUser
HasaccesstoaspecificDVMfor everydayuse.
SubjectMatterExpert
Applicationownerthatprovides supportforspecificapplications withintheproductivitynetwork. Responsibleforqualityassuranceof virtualapplicationpackages.
ApplicationOperator
Managesapplicationallocationand accessrights.Controlsthestreaming engineandmanagestheapplication repository.
ApplicationPackager
Preparesapplicationsfor virtualizationthroughtheuseofthe applicationvirtualization(AppV) packagingtool.
Desktop Virtualization
Application Virtualization
Table16-1. NewITRolesinVirtualInfrastructures
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Asyoucansee,policiesareattheheartoftheautomationofprocesseswithinavirtualinfrastructure.Butyoucantakethisonestepfurthertocreatepoliciesthataffecthost serversasmuchasvirtualmachines.Inthisscenario,VirtualServiceOfferings(VSOs) arepoweredonandoffonanas-neededbasis,andresourcepoolsarepoweredupbased onVSOworkloads(seeFigure16-2).Forexample,apayrollapplicationonlyrequires extensiveresourceswhenitrunsthepayrollpayload.Dependingonyourpayschedule, thiscanbeeverytwoweeksortwiceamonth.Fortherestofthetime,thepayrollmachineis“atrest”andcanbeparkedonahostserveralongwithothervirtualmachines. Inparkedmode,themachinestillruns,butdoesnotdrawuponextensiveresources. Youcanevenextendthisfeaturetoallofyourworkloads.Forexample,alargedatacentercanpopulateservicesasneeded.ThereisnoreasontoruntenExchangeServersat nightwhennooneisusingthem.Youcan,however,runtwoofthesemachinesatnight andthensetpoliciesthatwakeuptheothersandtheircorrespondinghostswhenthey areneeded—forexample,atpeaktimes,suchasearlyinthemorningandafterlunch.
Figure16-2. Policy-basedworkloadsatwork
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Running policy-based workloads changes the datacenter paradigm and provides evengreatersupportforgreeningthedatacenter.Ifhostserverscanbeatrestandrun onlywhenrequired,itwillhaveapositiveimpactonthedatacenter’spowerandcoolingbottomline.Buttocontrolthisnewdynamicdatacenter,youmusthavetheright toolset. NOTE VendorCassattalreadyoffersautomatedpowerefficiencysoftware;seetheirpowersaving calculatoratwww.cassatt.com/tools/powersavecalc.php.
NOTE MicrosofthasupdateditsWindowsServerproductlicensing.Before,eachlicensewastiedto thephysicalserver,thatis,thehostwheretheVMwasrunning.Now,licensesaretiedtoadatacenter orapoolofhostservers.Thismeansthatyoucanusepolicy-basedworkloadmanagementwithout havingtoworryaboutreassigninglicenseseachtimeaVMmovesfromonehosttoanother.
POLICY-BASEDRESOURCEMANAGEMENT Policy-basedresourcemanagementrequiresnotonlyanewviewofthedatacenter,but italsorequirestherighttoolforthejob.Virtualizationvendorshavecomealongway towardscompletingthedifferenttoolsetsrequiredtorunthevirtualdatacenter,butin some cases, these tools will not be enough. Table 16-2 describes the different features required in the virtual datacenter and the management tools provided by VMware, Microsoft, and Citrix to meet these features’ requirements. Keep in mind that virtual infrastructuremanagementmustfocusonfourkeyfunctionsasyoulookthroughthe contentsofTable16-2:
▼ M anagingdriverstobeusedinvirtualmachines(integrationcomponents, VMwareadditions,andsoon).
■ AllocatingorbuildingVMspacesforguestoperatingsystems.
■ M onitoringVMcharacteristics(RAM,processorcores,diskspace,I/O)and providingalarmswhenneeded.
▲ Loading,unloadingandbackingupeachVM.
These are the four basic functions required of any virtual machine management tool. Anyadditionalfunctionisabonus. Asyoucansee,bothVMwareandMicrosoftofferanextensiveselectionoftoolsto support the dynamic datacenter. However, even though both VMware and Microsoft havetoolslistedinparticularsectionsofTable16-2,thetoolsdon’tnecessarilyhavethe same feature set. For example, VMware Lifecycle Manager offers a feature set that is morecomprehensivethanVirtualMachineManagerwhenitcomestoVMprovisioning automation.AnotherexampleiswithVMware’sDistributedPowerManagementcomparedtoMicrosoft’sOperationManagerwhenitcomestohostpowermanagement.
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Microsoft
Hyper-VConsole SystemCenter (SC)Virtual MachineManager VMProvisioning LifecycleManager SCVirtual MachineManager Windows VMAutomation Infrastructure ToolkitforWindows PowerShell (inWindowsServer (PowerShell) 2008) VMware Infrastructure PerlToolkit LiveVMMigration VMotion QuickMigration LiveMigrationto comeinWS08R2 HighAvailability Failover Site-LevelHigh Availability:VMs Clustering Site-LevelHigh StorageVMotion WindowsServer Availability:Storage SimpleSAN Backup Consolidated Windows Backup ServerBackup SCDataProtection Manager Volume ShadowCopy SCOperations VMPlacement Distributed Managerwith Management Resource SCVirtual Scheduler MachineManager Security VMsafe WindowsServer Integration PatchingandUpdates UpdateManager WindowServer UpdateServices SCConfiguration Manager HostPower DistributedPower SCOperations Management Management Managerat hostlevel Failover SiteRecovery WideArea Clustering Manager Network(WAN) Geoclusters businesscontinuity management(BCM)
Table16-2. RecommendedFunctionsforVirtualizationManagement
Citrix XenCenter
XenCenteror third-party Third-party
XenMotion
ResourcePool Third-party Third-party
XenCenter
XenAccess (indevelopment) XenCenterforhosts WindowsServer UpdateServices (WSUS)forVMs Third-party Third-party
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AnothermajordifferenceisthatVMwareoffersitsentiretoolsetwithinVirtualCenter,addingfunctionalityasyoumoveforwardwithadditionalfeatures.VirtualCenter supports seven different key functions—basic virtual machine and host management, provisioning,migration,resourcemanagement,systemmonitoring,security,andaccess control—andalsoprovidesanapplicationprogramminginterface(API)forthird-party integrationwiththetool(seeFigure16-3). Tofacilitatetheacquisitionofallofthetoolsyourequiretomaintainthedynamic VMwaredatacenter,VMwareofferstwosoftwarebundlesalongwiththeVirtualInfrastructureeditions.TheVMwareITServiceDeliverybundleincludesVMwareLifecycle Manager,LabManager,andStageManager,lettingyoucontrolVMlifecyclesthrough automatedpolicies.TheVMwareManagementandAutomationbundleincludeseverythingfromthepreviousbundleaswellasSiteRecoveryManager. Citrix’s XenCenter is similar to VirtualCenter in that it provides a single interface foroperationandmanagementoftheresourcesforbothhostsandvirtualmachines(see Figure16-4).Hostserverscanbemanagedindividually,aswiththeExpressandStandardEditions,orthroughresourcepoolswiththemoreadvancededitions.Theinterface providesallbasicmanagementfunctionalityinonetool. Microsoft’s toolset relies mostly on System Center tools, which all have the same lookandfeel,butwhichareallseparatetools.However,forsinglemachineandpool management,MicrosoftreliesontheHyper-VManager,whichisavailableeitherasa
Figure16-3. VMwareVirtualCenteroffersseveralfeatures.
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Figure16-4. CitrixXenCenterprovidesoneinterfaceforXenServermanagement.
stand-alonetool(seeFigure16-5)orasanadd-intotheWindowsServer2008Server Manager (see Figure 16-6). The latter is often preferable if you do not have access to SystemCentertoolsbecauseitbringstogetheralloftheservermanagementfeatures in one single interface. Note, however, that Server Manager cannot be installed on a workstation because it is an integral part of Windows Server. Because of this, many organizationstendtoinstallTerminalServicesinapplicationmodeontheirserversand useittopublishServerManagerasaremoteapplicationthroughtheTerminalServices RemoteApp feature. This gives administrators the same experience as with a locally installedtool. ServerManagercannotmanageremotemachinesandcan,therefore,onlybeused onfullinstallationsofWindowsServer2008(WS08).IfyouinstalltheHyper-Vroleon Server Core—as you should to reduce host operation overhead—you will not be able to rely on Server Manager and will have to fall back on the individual interfaces for Failover Cluster and Hyper-V management. Both of these are available through the Remote Server Administration Tools (RSAT), which are available for both x86 and x64versionsofWindows.RSATcanbeinstalledonlyonWindowsServer2008orWindowsVistawithServicePack1. NOTE RSAT for x86 can be found at www.microsoft.com/downloads/details.aspx?FamilyID= 9ff6e897-23ce-4a36-b7fc-d52065de9960&displaylang=en and RSAT for x64 can be found at www .microsoft.com/downloads/details.aspx?FamilyId=D647A60B-63FD-4AC5-9243-BD3C497D2BC5& displaylang=en.BotharedocumentedinMicrosoftKnowledgeBasearticlenumber941314.Validation ofGenuineWindowsisrequiredtoobtainthedownload.
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Figure16-5. UsingHyper-VManager
But when you run virtual infrastructures, everything but the simplest infrastructuresrequiresthebasefunctionsfoundinVMware’sVirtualCenter.Inordertoachieve thisleveloffunctionality,youneedMicrosoft’sSystemCentertools.Smallershopscan relyonSystemCenterEssentialsalongwithSystemCenterVirtualMachineManager (SCVMM)WorkgroupEdition.WorkgroupEditionsupportsuptofivehostservers. LargershopsrequiretheentireSystemCentertoolkit,whichisavailablethrough aspecialbundle—theServerManagementSuiteEnterprise(SMSE)—whichincludes fourtools:
▼ S ystemCenterConfigurationManager(formerlySystemsManagementServer), whichcanprovisionmachines,eitherhostsorVMs,aswellasmanagetheir configurationandmaintainconfigurationcompliance.
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Figure16-6. UsingWS08ServerManagertomanageHyper-V
■ S ystemCenterOperationsManager(SCOM),possiblyMicrosoft’sbesttool,is designedtomonitorthehealthandperformanceofhostservers,VMs,andthe applicationswithintheVMs.SCOMreliesonmanagementpackstosupport anyserverworkloadorapplication.Third-partyvendorssuchasnWorks (www.nworks.com)evenoffermanagementpacksforVMwareESXServer, lettingyoumanagemixedenvironmentsthroughonesingletool.
■ S ystemCenterDataProtectionManager,whichisacontinuousprotectiontool thatcanbeusedtocentralizeallbackupandrecoveryoperations.
▲ SystemCenterVirtualMachineManager,whichmanageshostandVMoperations.
Thisbundlesimplifiesmanagement,andwhileeachofthetoolsoffersthesameinterface (seeFigure16-7),theyareseparateandindependenttools.
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Figure16-7. SystemCentertoolssuchasVirtualMachineManagerallrelyonthesameinterface.
LOOKTOTHIRD-PARTYMANAGEMENTTOOLS Whileeachvendorofferspowerfulmanagementtoolsfortheirhypervisors,andsome willevenmanagetheircompetitors’hypervisors,youmightfindthatsomefeaturesand functionsaresimplynotcoveredbythistoolsetandthatthird-partytoolsarerequired. Table16-3providesasamplelistofsomeofthemostinnovativethird-partytoolstodate. Otherswillsurelyfollowintheirfootstepsasvirtualizationbecomesmainstream. Asyoucansee,third-partytoolstrytoaddressneedsthathavenotbeenaddressed bythebigthreeyet.VMoptimization,multivendorlifecyclemanagement,hostserver provisioning,and,especially,controlovervirtualmachinesprawlareallfunctionsyou willeventuallyneedinyourenvironment.Forthesereasons,obtainingathird-partytool mightbethebeststrategyformany.
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VendorProduct
Description
Akorri (www.akorri.com)
BalancePoint:Agentlesstoolfocusedonsystem monitoring,utilizationoptimization,and performanceimprovementsofhostsandVMs. SupportsCitrix,Microsoft,andVMware.
CiRBA (www.cirba.com)
DataCenterIntelligence:Policy-basedmanagement toolthatdynamicallyreassignsVMworkloadsin thedatacenter.Excellentvirtualizationassessment tool.Constantlycapturesandanalyzestechnical, business,andresourceconstraintstomanage workloadsandensuretheyhavetheappropriate resourcesavailable.
DynamicOps forCitrix,Microsoft, VMware,andSolaris (www.dynamicops.com)
VirtualResourceManager:Lifecyclemanagement toolthatincludesaself-serviceportal,controls VMsthroughpolicies,tracksresourceusage,and providesextensivereporting.Supportsscalability throughfederation.Supportsmultivendor virtualizationdeploymentsforCitrix,Microsoft, andVMware.
Embotics (www.embotics.com)
V-Commander:Policy-basedVMmanagement product.SupportsfullautomationofVMlifecycles. Supportsmultivendorvirtualizationenvironments runningCitrix,Microsoft,orVMware. V-Scout:Freeagentlesstoolthatlinkswithupto twoVMwareVirtualCenterserverstoprovide VMinformationinrealtime.
Fortisphere (www.fortisphere.com)
VirtualEssentials:Asuiteofpolicy-based virtualizationmanagementsolutionsthatprovides visibility,control,andautomationaroundthe inventory,configuration,andpolicy-based managementofvirtualmachines. VirtualInsight:Anoperationalmanagementproduct thatenablesenterprisestoautomatetheprocess ofidentifying,tagging,tracking,andreporting onallvirtualmachinesastheymovethroughout preproductionandproductionenvironments. Providesvisionintoallvirtualmachines,centralized ordistributed.
Table16-3. SampleThird-PartyManagementTools
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VendorProduct
Description VirtualForesight:Apolicy-basedmanagement productthatdeliversout-of-theboxbestpractices forenforcingoperationalandITsecuritypoliciesin virtualenvironments.Itensurespolicyenforcement throughoutthelifecycleofavirtualmachine, regardlessoflocationorstate.
Scalent (www.scalent.com)
Virtualization:Actsasthepre-bootenvironmentfor hypervisors,takingphysicalmachinesfromadead, bare-metal,powered-offstatetoinstalled,operating, connectedVMwareESXorXen.Focusedonhost serverrepurposing.
VEEAM (www.veeam.com)
Backup:Abackupanddatareplicationtoolthatis designedtoprotectVMsinVMwareESX. ReporterEnterprise:Adatacollectionandreporting toolforentireVMwareinfrastructures. Monitor:Amonitoring,capacityplanning,and troubleshootingtoolforVMwareinfrastructure management.
Vizioncore (www.vizioncore.com)
vRangerPro:Abackupandrecoverysolutionfor virtualizedenvironments.Canscheduleregular image-levelbackupsofvirtualorphysicalmachines whilethemachineisstillrunning.Supports VMware. vConverter:Physical-to-virtual(P2V)enginethat usesacloningmethodexecutedattheblocklevel asopposedtothefilelevel.Cancreateimagesof bothphysicalandvirtualmachinesthatcanbesent andarchivedataremotesite.CanaddonaP2VDRmodulethatcanextendthedisasterrecovery strategytocoverthephysicalmachines. vReplicator:Host-levelsoftware-basedreplication solutionforVMwareinfrastructuretoleverage virtualizationtosupportHighAvailability(HA)and BCMstrategies. vCharterPro:Monitoringtoolthatprovidesasingle viewintomultiplelayersofvirtualenvironments.
Table16-3. SampleThird-PartyManagementTools(continued)
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Update Your Management Structure
Description vOptimizer:Anoptimizationsolutionthatreducesa virtualmachine’svirtualharddrivetothesmallest sizepossiblewhileoptimizingWindowsguest operatingsystemforspeedandperformance. Comesintwoeditions:DesktopandNetwork. vEssentials:ManagementbundleforVMware InfrastructurethatincludesvRangerPro, vReplicator,andvCharterPro. VDRforSMB:BundlesVMwareVirtual InfrastructureStarterEditionwithvEssentials. ProvidescompleteBCMforsmalltomedium businesses.
Table16-3. SampleThird-PartyManagementTools(continued)
UPDATEYOURMANAGEMENTPRACTICES Virtualmachinemanagementandresourcepooladministrationbringmanychangesto themoderndatacenter.Becauseofthis,youneedtoupdateyourmanagementpractices. Insmallshops,ITpersonnelwillhavetolearntowearnewhatsandbeespeciallycareful nottotraversesecurityboundarieswhentheyperformtheiractivities.Inlargershops, you’llwanttocreatespecificpositionsforresourcepoolversusVirtualServiceOffering managementandkeepthemseparated. Theidealdynamicdatacenterisonewhereresourcepoolsarebundledresourcesthat areonlyavailableforhostingservices.Virtualmachinesofferallotherservicesasmuch aspossible.Thisdualityisnowafactandisthewaydatacenterswillrunandoperate movingforward.Makesureyoucarefullyexamineyourcurrentpracticesandbepreparedtoupdatethemasyoutransformyourdatacenterintoadynamicenvironment.
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Afterword
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Y
ou now have a good understanding of how virtualization can transform your datacenter. Now you need to look at your adoption path. According to IDC, organizationsthathavemadethemovemostoftenuseathree-tieredapproach (seeFigure1).First,theyfocusoncapitalexpendituresandaimforphysicalconsolidation. Next, they move to operational changes and focus on the implementation of high availabilityanddisasterrecovery.Finally,theybegintoviewthestrategicadvantages virtualization offers and truly begin to transform their datacenters into the dynamic systemstheyshouldbe. Beginwithyourshort-termneeds.Mostoften,organizationshaveproblematicapplicationsthatcanimmediatelyprofitfrombeingvirtualized.Then,onceyourinfrastructureisstable,looktothelongterm.Youshouldaimfor100percentvirtualization,but keepthefollowingcaveatsinmind:
▼ V irtualizeapplicationsunlesstheapplicationownerorvendorcanprovidea costjustificationfornotdoingso.
■ Aimfor60to70percentutilizationratiosonyourhostservers.
■ K eephostserverfarmsorresourcepoolstoamaximumofeightserversorfewer tomaintainmanageability.VMwaresupports32machinesinafarm,while MicrosoftHyper-VandCitrixXenServerwillsupport16.However,creating farmswiththemaximumnumberofnodestendstomakethemunwieldy.
Figure1. Potentialadoptionpaths(Source:IDC,Virtualization2.0:TheNextPhaseinCustomer Adoption,Nov.2006)
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Afterword
■ D esignforVirtualServiceOfferinghighavailability.Youwanttoensureyour machines,atleastthemachinesthatofferproductionservices,areavailableat alltimes.
■ M atchprocessortypesineachserverfarmtosupportlivemigrationcapabilities, andstartanewserverfarmeachtimeaprocessortypechanges.Thoughthisis changing,itisstillagoodpracticefornow.
■ M akesureyouperformcostaccountingforeachvirtualmachine(VM)running onahost—it’seasytolosetrackofVMcostsbecausetheyaresoeasytocreate anddeploy.
▲ U seaspecificVMallocationprocess,bothadministrativeandtechnical,toensure thatonlyrequiredVMsmakeitintoyournetwork.
These practices are good strategies. Keep them in mind as you move forward with yourproject.
CALCULATEYOURRETURNONINVESTMENT Finally,you’llwanttoperformaprojectpost-morteminwhichyouwillcalculateyour returnoninvestment(ROI).You’llfindthatharddollarsareeasytocomeupwith,but thesoftdollarsaremuchhardertolocate.Keepthefollowingquestionsinmindwhen calculatingyourROI:
▼ H owmuchdoyouvaluethetimeyousaveinpreparingavirtualversus aphysicalserver?
■ H owmuchdoyouvaluethepreparationofstandardtestinganddevelopment environments?
■ H owmuchdoyouvaluetheflexibilityavirtualinfrastructuregivesyouto meetchangingbusinessneeds?
▲ H owmuchdoyouvaluethereducedtimetomarketforallofyourcore applications?
Timeismoney,butitishardtoquantify.Table1outlinessomeofthepotentialcost savingsyouwillbenefitfromwhenyoumovetovirtualization. Virtualization will also change the metrics in your IT department (see Figure 2). Youcanreducecapitalexpendituresbyupto50percent.Responsetimeswilldecrease, sometimesbyupto90percent.Operatingexpenses,especiallypowerandcoolingcosts, willbegreatlyreduced.Andrecoverytimeswillalsobenefitfromthismove. Thisisonlythebeginning.Bythetimeyoumovetoavirtualinfrastructure,dozens ofnewfirmswillhaveappearedandhundredsofnewproductswillbeavailable.The futureisnow,andintermsofIT,itmeansvirtualizationofeverythingthatmovesin thedatacenter.
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Category
PotentialSavings
Powersavings
$300to$600pervirtualizedserver
Coolingsavings
Upto$400pervirtualizedserver
Hardwaresavings
From$2,500to$$$pervirtualizedserver
Licensesavings(Microsoft)
75percentofEnterpriselicenseper virtualizedserver
Licensesavings(open-source) Nil,exceptforsupportcosts Processorpowersavings whenusingAMD
Between15to65percentperprocessor
Powerrebates (selectedutilityfirms)
Upto50percenttotalcostoftheproject
Governmentrebates Variablereductionrates(incometax, (federal,provincial,andstate) rebates,andmore) Spacesavings
90-pluspercentspacereduction(basedon anaverageoftenVMsperphysicalhost)
Table1. PotentialandRealCostSavings
Figure2. Potentialreturnsfromvirtualization
INDEX ▼
A
ABE(Access-BasedEnumeration),292 AccessFabric(Desktone),261 Access-BasedEnumeration(ABE),292 ACE(VMware),243,255 AcressoSoftware: AdminStudio,29 InstallShieldAdminStudio,268 Acronis,225 ActiveDirectory(Microsoft),250,279 ActiveDirectoryCertificateServices (ADCS),350–352 ActiveDirectoryDomainServices (Windows),22,137,337 ActiveDirectorystructures,391 Adhoclayer,inPASSmodel,236–237
ADCS(ActiveDirectoryCertificate Services),350–352 Administrativerights,ofusers,213 Administrativeroles,404 AdminStudio(AcressoSoftware),29 ADS(AutomatedDeployment Services),229 Affordability,ofvirtualappliances,222 Agent-basedapplication virtualization,277–278 Agentlessapplicationvirtualization, 42,277,278 Allocationlayer,56 AltirisWisePackageStudio,268 AMDprocessors,67–69,107 AmericanPowerConversion,70 Antimalwareagent,278
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Antimalwarestrategies,334–335 Antivirusverification,forlaboratories,148 APCTradeOffTools,75,76 AppleComputer,25 Applicationlayer(desktops),238,239 Applicationlayers(applications),266 Applicationlifecycle,267–268 Applicationmanagement,266 withapplicationlifecycle,267–268 withapplicationpackaging processes,270–271 issuesin,14–15,266–272 withpresentationvirtualization, 271–272 forredesign(seeApplication virtualization) traditionalsolutionsfor,267 withWindowsInstallerservice, 268–269 Applicationpackagingprocesses, 270–271 ApplicationPlatformAssessment,83–85 Applicationservers,22,198 Applicationsponsors,237 Applicationstreaming,281–283 Applicationvirtualization(AppV),29, 40–43,272–283 ActiveDirectoryintegration,279 advantagesof,42,273–274,294–295 agentvs.agentless,277–278 agentless,42 applicationstreaming,281–283 benefitsof,283–284 andbusinesscontinuity,392–394 CitrixXenApp,290 comparingproductsfor,286–289 componentsof,274–275 decisionprocessfor,294 InstallFreeBridge,290–291 integrationofdesktopandprofile virtualizationwith,298–309 keypointsabout,294–296 localrepositorymanagement, 278–279
majorvendorpositioning,293 MicrosoftApplication Virtualization,291 potentialsolutions,289 asprotectivelayer,273 selectingsolutionsfor,275 SoftwareasaServicemodel,280–281 softwarepackaging,280 SymantecSVSPro,291 systemstack,275–276 technologiesandvendorsfor, 286–288 TenCommandmentsof,295 throughstreamingtechnologies, 41–42 VMwareThinApp,292 andWindowsversion independence,277 ApplicationVirtualization(Microsoft), 34,41,291 Applications: categorizing,22 lifecyclesof,237,267–268 AppSync(ThinApp),292 Architecturesstep(invirtualization process),55–57 Ardence,257,258 AssessmentandPlanningToolkitSolution Accelerator(Microsoft,MAP),16–18 Assetdisposal,green,11 Assigneddesktops,248 Authentication,343 AutomatedDeploymentServices (ADS),229 Availability,withclustering,383
▼
B
Back-endmanagement,250 Backupverification,forlaboratories,149 Backups,32 oflaboratoryinformation,147–148 replicationfor,367
Index
selectingmethodfor,112 instorageconfiguration,106 third-partytoolsfor,367–368 whenbuildinglaboratories,147 BartPE,229 Baseenvironment,reuseof,144 BaselineSecurityAnalyzer(Microsoft, MBSA),15,16 BasicConsolidationEstimate(BCE), 88,331 BasicInput/OutputSystem(BIOS),68 Basicproductivityworkers,247 BasicstageofITmaturity,154,155 BCE(BasicConsolidationEstimate),331 BCM(seeBusinesscontinuity management) Bestpractices: forlaboratories,149–150 forprovisioningvirtual machines,231 inservervirtualization,207 withvirtualappliances,221 BIOS(BasicInput/OutputSystem),68 BIOSsecurity,331 Bladeenclosures,53–54 BladePCs,297 Bladeservers,108 BlueScreenofDeath(BSOD),4 Bridge(InstallFree),42,290–291 BSOD(BlueScreenofDeath),4 Buildingconstruction,protecting,330 Buildingsecurity,330 “Bull’seye”endpointsystemstack,298 Businesscontinuity,370–401 buildingstrategyfor,394–401 makingprofileshighlyavailable,394 makingresourcepoolhighly available,372–379 makingvirtualapplicationshighly available,392–394 makingvirtualdesktopshighly available,387–392 protecting,328
protectingVirtualService Offerings,380–387 withvirtualappliances,222 Businesscontinuitylayer,56 Businesscontinuitymanagement(BCM), 395,401 BusinessProductivityInfrastructure Assessment,83,84 Business-criticalsystems,395
▼
C
CA(seeCertificateauthorities) Cachecontrol,278 CalistoTechnologies,247 Callcenters,93 CapacityPlanner(VMware),20 Cassatt,408 CastleDefenseSystem(CDS),315–327 forbusinesscontinuity,370 criticalinformationlayer,315, 327–330 defenseplansupplementing, 352–353 externalaccesslayer,316,348–352 informationaccesslayer,315, 342–348 layersin,315–316 operatingsystemhardeninglayer, 315,332–342 physicalprotectionlayer,315, 330–331 inplanningforsystem redundancy,372 forresourcepool,317–322,327–352 forVirtualServiceOfferings, 317–318,322–327 Celerra(EMC),252–253 Centralizeddesktopvirtualization, 248–249 Centralizedmanagementdata,329 Certificateauthorities(CA),350–351,379
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Certificates,349 Changelog,forlaboratories,149 CiRBA: DataCenterIntelligence,20,21 PlacementIntelligenceTechnology tool,70 Citrix(company),155–156,180 Citrixtechnologies,34,157 applicationvirtualization,290,293 pricingcomparedtoothervendors, 185–187 replication,398 servervirtualization,7,173–176 VDIsolutions,249 XenApp,34,41,290 XenDesktop,34,257–260 XenServer,7,34,35,174–175, 361–362 (Seealsospecificapplications) Client-sideDesktopVirtualization,240 Cloningphysicalmachines,229 Clustering,378 complexworkloadswith,214 multisite,376–377 ofsharedstorage,99 testing,137 ofvirtualmachines,58 inVirtualServiceOfferings, 381–387 Collaborationservers,22,198 Commercialsoftware,inPASS model,236 Communications,encrypting,348–349 Complexworkloads,214 Comprehensiveanalysis,66–90 additionaltoolsfor,81–85 existingnetworkbandwidth review,73–74 hardwarelayersevaluations,70–71 powerandcoolingaudit,74–80 rationalization,88–90 serverconsolidationstudy,85–88 serverprocessors,67–69 storageconsolidationstudy,71–73
Configurationfile,30 Configurations,ofvirtualmachines, 127–128 Conflictdetection,266–269 Connectix,24,176 Consoleservers,securityfor,333–334 ConsolidatedBackup(VMware),166, 168,359–361 Converter(VMware),226–228 Copiesofvirtualmachines,135 Coreenvironment,reuseof,144–145 Coremachines,reuseof,142 CoreOSlayer(desktops),238,239 CPUsteppingvalues,68 Criticalinformationlayer(CDS),315, 327–330 protectingmanagementdata, 329–330 protectingvirtualdiskdrives, 328–329
▼
D
DAAS(DesktoneDesktopAsAService), 261–262 DAS(seeDirectattachedstorage) DataCenterCapitalCostCalculator, 77,78 DataCenterCarbonCalculator,75,76 DataCenterEfficiencyCalculator, 75,76 DataCenterInRowContainment Selector,78,80 DataCenterIntelligence(CiRBA),20,21 DataCenterPowerSizingCalculator, 78,80 Dataprotection,328,366–367 DataSynapse,29 Databaseprotection,329,372 Datacenters: green,8–11 serverutilizationin,4 DDoS(DistributedDenialofService),381
Index
Decisionflowchart,60–61 Decisionprocess: forapplicationvirtualization,294 fordesktopvirtualization,264 forservervirtualization, 194–197 virtualizationdecisionflowchart, 60–61 Dedicatedwebservers,22,198 Defaultbackuptechnologies,148 Defaultdomainpolicy,343–345 Defenseplan,352–353(SeealsoCastle DefenseSystem) Deliverables: reuseof,142–145 ofvirtuallaboratories,138–141 Demilitarizedzone(DMZ),346 Denialofserviceattacks,381 Depersonalizedmachines,reuse of,142–143 Deployment: ofagents,277–278 AutomatedDeployment Services,229 on-demand,282–283 ofpackagesinMSIformat,271 ofvirtualappliances,221 inVirtualServiceOfferings lifecycle,211 Desktone,249,261–262 Desktop(InstallFree),260–261 DesktopAsAService(Desktone,DAAS), 261–262 DesktopManagementTaskForce (DMTF),180 Desktopvirtualmachines(DVMs), 253–256,373,378–379 Desktopvirtualization(DeskV),28, 38–40,234–264 andbusinesscontinuity,387–392 centralizedinfrastructuremodels, 248–249
withCitrixXenDesktop,257–260 withDesktoneDesktopAsA Service,261–262 identifyingaudiencesfor,246–248 withInstallFree,260–261 integrationofapplicationandprofile virtualizationwith,298–309 keypointsabout,310 licensing,241–243 managementissueswith,237–238 potentialscenariosfor,243–246 productsfor,240–241 profitfromVDIs,262–264 withQuestVirtualAccess Suite,262 reasonsfor,39–40,239–240 withsystemstack,234–237 technologiesandvendors,242 withVMwareVirtualDesktop Manager,250–256 Desktops,234,238–239 DeskV(seeDesktopvirtualization) Developmentenvironments,workload requirementsfor,195–197 DevelopmentVMs,protectionof,328 DFS(seeDistributedFileSystem) DFSnamespace(DFSN),302,392 DFSreplication(DFSR),392 DFSN(seeDFSnamespace) DFSR(DFSreplication),392 DHCP(seeDynamicHost ConfigurationProtocol) DIMMs(DualInlineMemory Modules),109 Directattachedstorage(DAS),72,73,103 Directoryservices: hardening,337–339 highavailabilityfor,380 Disasterrecovery: withAppV,284 forlaboratories,147–148 withvirtualappliances,222
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Discoverystep(invirtualization process),14–23 categorizingserverresources, 21–23 inventory,15–16 rationalizationin,23 scanningforcandidates,16–21 Diskformats,180–182 Disksizing,111 DistributedDenialofService(DDoS),381 Distributeddesktopvirtualization,248 DistributedFileSystem(DFS),302, 381,392 DistributedPowerManagement(DPM), 169,170 DistributedResourceScheduler(DRS), 169,170,207 Distributedsystems,levelsof componentswith,297 DLL(DynamicLinkedLibraries),266–267 DLLHell,266–268 DMTF(DesktopManagementTask Force),180 DMZ(demilitarizedzone),346 DNS(seeDomainNameSystem) Domainloginprofiles,299–300 DomainNameSystem(DNS),96–97 inDVMinfrastructure,391 highavailabilityfor,380 Downtime,withP2Vconversion, 223–224 DPM(seeDistributedPower Management) Drivereplication,instorage configuration,106 DRS(seeDistributedResource Scheduler) DualInlineMemoryModules (DIMMs),109 DVMs(seeDesktopvirtualmachines) DynamicHostConfigurationProtocol (DHCP),99 inDVMinfrastructure,391 highavailabilityfor,380
DynamicLinkedLibraries(DLL), 266–267 DynamicstageofITmaturity,154,155
▼
E
Easyworkloads,213 ElectronicSoftwareDistribution(ESD), 273,274,277,297,393 EMC: Celerra,252–253 FileSystemAssessment,72 Encapsulation,40 Enclosures,53–55 Encryption: forcommunications,348–349 ofdesktopVMs,243 Enterprisearchitectures,58–59 Entrust,349 Environmentstandardization,159 ESD(seeElectronicSoftware Distribution) ESXServer(VMware),161–165 directoryservicehardening,337 securityfor,332–333,335 ESXi(VMware),33,35,161–165 Eventlogverification,forlaboratories,148 Externalaccesslayer(CDS),316,348–352 internalPublicKeyInfrastructure, 350–352 SecureSocketsLayer,348–349 Windowsservers,347–348 ExternalUSBdisks,195 Extraneoussystems,395 Extranetinteraction,315
▼
F
FailoverClustering,380,381,397 Failsafeservers,199 FibreChannel,103,381 Fileandprintservers,22,198
Index
Fileshares,highavailabilityfor,381 FileSystemAssessment(EMC),72 Filesystemsecurity,335–337 Filetypes,31–32 Firewalls,97,347 Five-stepvirtualizationprocess,11–12 Architecturesstepin,55–57 Discoverystepin,14–23 HardwareMaximizationstepin, 46–55 ManageVirtualizationstepin, 57–61 Virtualizationstepin,23–43 Flexibility,withAppV,284 Folderredirection,301–309 withroaminguserprofiles,307–309 inWindowsVista,303–307 inWindowsXP,303 Freespaceverification,for laboratories,148 Fully-automatedP2V,223 Functionaltestinglevel,122,129, 132,133 Fusion(VMware),255
▼
G
GAL(generalizedapplicationlayer),278 GAL(globalapplicationlayer),279 Gartner,154 Generalizedapplicationlayer(GAL),278 Geographicallocation,protecting,330 Globalapplicationlayer(GAL),279 GoodtoBeGreenWebsite,8,9 GPOs(GroupPolicyobjects),343 Greenassetdisposal,11 GreenAssetDisposalWebsite,11 Greendatacenters,8–11 Greentechnologies,buying,10–11 GroupPolicy,301,390–391 GroupPolicyobjects(GPOs),343 Growthpotential,112
Guestoperatingsystems: defined,29 hypervisorsupportfor,190 numberof,110 virtualizationtechnology vendors,34 GuidedConsolidation(VMware,VGC), 18–19
▼
H
Harddiskfile(s),31 HardV(seeHardwarevirtualization) Hardwarelayersevaluation,70–71 HardwareMaximizationstep(in virtualizationprocess),46–55 licensingcosts,51–53 moveto64-bit,46–48 newserverformfactors,53–55 sharedstorage,48–49 Hardwareprotection,112 Hardwarevirtualization(HardV),25,33, 156,157 Helpdesk,159 Hewlett-Packard(HP),53–54,261 Highlyavailableconfigurations,100–102 applications,392–394 profiles,394 resourcepool,372–379 virtualdesktops,387–392 Homedirectory,302 Hong,Qui,229 Hostservers: defined,29 highlyavailable,373,375 IPaddressesfor,96 forlaboratories,126–127 maintenanceof,108 placementrulesfor,202–204 protecting,372 forresourcepool,107–117 scalingup/out,107–108
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Virtualization: A Beginner’s Guide
Hostservers:(Cont.) securityfor,332–333 singlevs.multi-VM,204–206 sizing,110–113 upgrading,114 Host-onlyvirtualnetworkcards,206 HP(seeHewlett-Packard) Humphries,John,74 Huss,Chris,229 Hyper-V(Microsoft),6,34,35,176,177 directoryservicehardening, 337,338 protectionstrategiesfor,362–366 replication,397 securityfor,333 Hyper-VManager(Microsoft),410–413 Hypervisorhardware,building,116–117 Hypervisors,30 choiceof,92 diskformatssupportedby,182 andflexmigration,69 hardware-integrated,114–116 manufacturerofferings,34–37, 359–366 metricsof,187–191 OracleVM,160 rundirectlythroughmanagement tool,329 virtualnetworkswitchesin,97,99 (SeealsoServervirtualization)
▼
I
IBM,24,25,35,261 ICA(seeIndependentComputing Architecture) Identitymanagementservers,22, 137,198 Imagepre-provisioning,260 Implementationcosts,66–67 Implementationmethod,choiceof,95 IndependentComputingArchitecture (Citrix,ICA),249,255
Informationaccesslayer(CDS),315, 342–348 GroupPolicyobjects,343–348 secureuseridentification,343 Informationassetcategories,371 Infrastructure: desktop,248,250(SeealsoVirtual desktopinfrastructure) ensuringavailabilityof,372 IT,spendingon,5 Infrastructuresecurity,314–353 applyingCastleDefenseSystemto resourcepool,327–352 CastleDefenseSystem,315–327 defenseplansupplementingCastle DefenseSystem,352–353 forlaboratories,146–147 (SeealsoSystemprotection strategies) In-housevirtualization,95 In-memoryfile,31 InstallFree,249 Bridge,42,290–291 Desktop,260–261 Virtual,260–261 InstallShieldAdminStudio,268,281 Integrationarchitecture,123 Integrationofapplication,desktop,and profilevirtualizationwith,298–309 Integrationtestinglevel,122,129, 132–133,136 Intel,108 Intelprocessors,67–69 InternalPublicKeyInfrastructure, 350–352 Internetinteraction,314 InternetSmallComputerSystems Interface(iSCSI),95–96,103 Intranetinteraction,314 Inventories,15–16 administrators’dislikeof,14 generating,15 Inventoryagent,277 IPaddresses,96
Index
IPSecurity(IPSec)-basedVirtualPrivate Network,346 iSCSI(seeInternetSmallComputer SystemsInterface) ITmaturity,stagesof,154,155
▼
K
KellSystems,55 Kerberossecurityprotocol,342–343,345 “Kernel,”PASSmodel,236 Kidaro(Microsoft),243 Knowledgeworkers,247
▼
L
LabManager(VMware),131–132, 170,197 Laboratories,120–151 bestpracticesfor,149–150 building,120–121 creationoflabenvironment, 133–141 hostserverconfigurations,126–127 maintenancepracticesfor,148–149 managementpracticesfor,145–149 physicalvs.logicalworkspaces,125 portable,136 requiredserverandworkstation roles,129–132 requirementsfortestinglevels, 132–133 reuseofdeliverables,142–145 testinglevels,122–124 usesof,121,137 virtualmachineconfigurations, 127–128 virtualmachinesoftwarein, 124–125 virtualmachineuseraccounts,129 virtualizationof,125 visualmapsof,137,138
Laverick,Mike,229 Layers,56–57,266 application,266 inCastleDefenseSystem,315–316 security,314 LDAP(seeLightweightDirectoryAccess Protocol) LeftHandNetworks,377 Licensecontrol,283 Licensing: foractualworkloads,211 costsof,51–53 fordesktops,241–243 byMicrosoft,207,241 forvirtualmachines,135 WindowsServer,186–187 Lifecycles: applicationvirtualization,295 ofapplications,237,267–268 machine,210 oftraditionalPCsvs.VDI,263 VirtualServiceOfferings, 210–213 LightweightDirectoryAccessProtocol (LDAP),22,141 Linux,5 Localinteraction,314 Localrepositorymanagement,278–279 LockeddesktopVMs,243 Logicalworkspaces,physical workspacesvs.,125 Logonissues,147,299–300
▼
M
Machinedeletionprocedure,for laboratories,149 Machinelifecycles,210–213 Mailboxservice,58 Maintenance: withclustering,383 ofhostservers,108 oflaboratories,148–149
431
432
Virtualization: A Beginner’s Guide
ManageVirtualizationstep (invirtualizationprocess),57–61 Manageability,withAppV,284 Managedproductusage,241 Managementdata,protecting,329–330 Managementissues: withdesktopvirtualization, 237–238 withvirtualmachines,59–60 Managementlayer,56 Managementpractices,145–149,417 Managementstructureupdate,404–417 managementpractices,417 newadministrativeroles,404 policy-basedresource management,408–414 policy-basedworkloads,404–408 third-partymanagementtools, 414–417 Managementvirtualmachines, protecting,373,378–379 Managementvirtualization(ManageV),28 ManualP2V,223 MAP(MicrosoftAssessmentand PlanningToolkitSolutionAccelerator), 16–18 MarathonTechnologies,377 MaturitystagesforIT,154,155 Maximumacceptableserverload,110 MBSA(MicrosoftBaselineSecurity Analyzer),15,16 MDOP(MicrosoftDesktopOptimization Pack),241 Mediafiles,101,102 Memoryballooning,164 Metrics: hypervisor,187–191 performance,86–87 MicrosoftCorporation,156,176 CalistoTechnologiesacquired by,247 Connectixacquiredby,24 OSproblemsof,4 supportforvirtualization,224
MicrosoftDesktopOptimizationPack (MDOP),241 MicrosoftDeveloperNetwork (MSDN),135 Microsofttechnologies,34,157 ApplicationVirtualization,34, 41,291 applicationvirtualization,291,293 AssessmentandPlanningToolkit SolutionAccelerator,16–18 BaselineSecurityAnalyzer,15,16 besteffortsupportpolicy for,35 conversiontools,229–230 desktop-based,156 Hyper-V,6,33–35,176,177, 362–366 licensingof,207,241 patching,341 forpolicy-basedresource management,408–414 pricingcomparedtoothervendors, 185–187 profilevirtualization,256 serverconsolidationsavings tools,82 servervirtualizationsolutions,7 servervirtualizationtechnologies, 176–180 SystemCenterVirtualMachine Manager,130–131,177 TerminalServices,34 VDIsolutions,249 virtualharddisks,31 VirtualPC2007,34 VirtualServer,176 VirtualServer2005,34 Visio,15,16 Vista,237 Windows,4,5 WindowsInstallerservice,14–15 WindowsServer,6,33,71,72,125, 176,177,186–187 (Seealsospecificapplications)
Index
Migration,223–224(SeealsoPhysical-tovirtualconversions) Minimumservercapacity,111 Min/maxmemorysettings,163 Mission-criticalsystems,395 Mission-supportsystems,395 MobileVirtualizationPlatform (VMware,MVP),29 MSDN(MicrosoftDeveloper Network),135 Multicoreprocessors,111 Multiprocessingservers,111 Multisiteclustering,99,376–377 Multisiteredundancy,395–396 Multi-VMhosts,204–206 MVP(MobileVirtualizationPlatform),29
▼
N
NAS(seeNetworkattachedstorage) NAT(seeNetworkAddressTranslation) NetApp,106–107,253,377 NetV(networkvirtualization),27 NetworkAccessProtection,346 NetworkAddressTranslation(NAT), 99,349 Networkattachedstorage(NAS),72, 73,99 replicationcapabilitiesfor,377 storageconfigurations,102 Networkbandwidthreview,70,73–74 Networkcards,206–207 NetworkFileSystem(NFS)container,102 Networkidentificationcards(NICs),96, 98,107 Networkinfrastructureservers,21,198 Networklayer: resourceallocationruleswith, 206–207 forresourcepool,95–99 NetworkLoadBalancing(NLB),99,137, 380–382 Networksecurity,331
Networkvirtualization(NetV),27 Networking,invirtuallayers,97–99 NextComputing,LLC,136 NextDimensionsystem,136 NFS(NetworkFileSystem)container,102 NICteaming,97 NICs(seeNetworkidentificationcards) NLB(seeNetworkLoadBalancing) NLB-compatible,384 Nonpersistentdesktops,249 Novell,35,161 NTFS,335,336
▼
O
OfflineDesktop(VMware),255,256 OfflineVirtualMachineServicingTool (Microsoft,OVMST),217,341–342 On-demandblocks,281 On-demanddeployment,282–283 Opendesktops,234 OpenVirtualizationFormat(OVF), 180–182,218,219 Operatingsystemhardeninglayer (CDS),315,332–342 antimalwarestrategies,334–335 directoryservicehardening, 337–339 fileandprintsystemsecurity, 335–336 finalactivitiesfor,339–342 securityforconsoleservers, 333–334 securityforhostservers,332–333 Operatingsystemvirtualization,30 Operatingsystems: newmigrationpathsto,40 problemswith,4–5 Vista,237 (SeealsospecificOSs) Operationalworkloads,214 Operations,keyelementsof,154,155 Optimization,withAppV,284
433
434
Virtualization: A Beginner’s Guide
OptimizationSelf-AssessmentTool,82–83 Oracle,35,135,160,224,378 OracleVM,160 Outsourcingofvirtualization,95 OVF(seeOpenVirtualizationFormat) OVMST(seeOfflineVirtualMachine ServicingTool)
▼
P
PacificGas&Electric(PG&E),8 Packaging,AppV,280 Parallels(parallels.com),161 Partners,forvirtualization,95 PASSmodel(seePointofAccessfor SecureServicesmodel) Passwords,146 Patchdeploymentagent,278 PCimages,time-controlled,40 PClayer,56 PCs(seePersonalcomputers) Performancemetrics,identifying,86–87 PerformanceMonitoringconsole,86–87 Perimeternetworks,346–347 Persistentdesktops,248,251 Personalcomputers(PCs),14,234 lifecycleofVDIvs.,263 securityof,331 Personalityprotection: inoperatingsystem management,299 policyfor,299–300 strategyfor,301–310 Personalizableclonedesktops,249 PG&E(PacificGas&Electric),8 Physicallayer,56 Physicallocationofservers,112 Physicalmachines: cloning,intoVMs,229 disposingof,11 partitioning,24,30 protecting,14 provisioning,14,217
Physicalprotectionlayer(CDS),315, 330–331 Physicalservers,21,160,198,200 Physicalworkspaces,logicalworkspaces vs.,125 Physical-to-virtual(P2V)conversions, 223–230 withMicrosoftconversiontools, 229–230 performing,225–226 withPlateSpinPowerConvert, 228–229 preparationfor,223–225 toolsfor,224–225 withUltimate-P2VforBartPE,229 withVMwareConverter, 226–228 PilotProjecttestinglevel,122,133 PlacementIntelligenceTechnologytool (CiRBA),70 Planningandpreparation,forresource pool,92–95 Planningphase(VirtualService Offeringslifecycle),211 PlateSpin: PowerConvert,21,228–229 PowerRecon,20,21 Player(VMware),255 PointofAccessforSecureServices (PASS)model,235–236,266, 277,278 Policy-basedresourcemanagement, 408–414 Policy-basedworkloads,30,404–408 Pooleddesktops,249 Portability,withAppV,284 Portablelaboratories,136 Powerandcoolingaudit,70,74–80 PowerConvert(PlateSpin),21, 228–229 PowerRecon(PlateSpin),20,21 Predictiveblocks,281 Preparationanddeploymentphase (VirtualServiceOfferingslifecycle),211
Index
PresentationServer(Citrix),272,290 Presentationvirtualization(PresentV), 29,271–272,297 Pricing,ofservervirtualization technology,185–187 Printsystemsecurity,336 Privatevirtualnetworkcards,207 Processors,multicore,111 Productionenvironments,workload requirementsfor,195,197 Productionphase(VirtualService Offeringslifecycle),212 Productivityapplicationlayer,298 Productivityserviceofferings,404 Productivityworkloads,213 Profilevirtualization,256,299–303 choosingprofilestoprotect, 300–301 integrationofapplicationand desktopvirtualizationwith, 298–309 personalityprotection,299–309 Profiles: andbusinesscontinuity,394 highlyavailable,394 Provisioningphysicalmachines,14 Provisioningvirtualmachines,210–231 bestpracticesfor,231 creatingseedvirtualmachines,216 machinelifecycles,210–213 performingphysical-to-virtual conversions,223–230 physicalvs.virtualprovisioning, 217–218 processfor,215 SCOPEclassificationtool,213–215 throughuseofseedmachines, 216–217 virtualappliancesfor,218–223 P2Vconversions(seePhysical-to-virtual conversions) Publiccertificates,349 PublicKeyInfrastructure,349–352
▼
Q
Quest,249 QuestVirtualAccessSuite,262
▼
R
RAC(RealApplicationClusters),378 RAID(seeRandomArrayofInexpensive Disks) RAM: forhostservers,108–109 sizing,111 RAMovercommitment,164 RandomArrayofInexpensiveDisks (RAID),103,104 Rationalization: incomprehensiveanalysis,88–90 ascoreprocess,216 inDiscoverystep,23 RationalizedstageofITmaturity,154,155 RDP(seeRemoteDesktopProtocol) RealApplicationClusters(RAC),378 RedHat,35,161 Redesignapplicationmanagement(see Applicationvirtualization) Redundancy,331(SeealsoBusiness continuity) Reliability,withclustering,383 Remoteaccess,283 RemoteDesktopProtocol(RDP), 255,272 RemoteServerAdministrationTools (RSAT),411 Remoteservers,protectionof,328 Remotesites,simulating,129 Renamedvirtualmachines,135 Replication: forbackups,367 businesscontinuitythrough, 397–399 choosingpropertoolfor,399–401
435
436
Virtualization: A Beginner’s Guide
Resiliency,withAppV,284 ResolutionsEnterprises,11,12(Seealso Five-stepvirtualizationprocess) Resourceallocationrules: hostserverplacementrules, 202–204 withnetworklayer,206–207 singlevs.multi-VMhosts,204–206 forvirtualworkloads,200–207 Resourcemanagement,policy-based, 408–414 Resourcepools(RPs),28,92–117 andbusinesscontinuity,372–379 CastleDefenseSystemfor,322–352 defined,30 highlyavailable,372–379 hostserversfor,107–117 Hyper-V,365–366 layersofprotectionfor,320–322 networklayerfor,95–99 planningandpreparation for,92–95 redundancyfor,373 securityfor,317–322 sizingrecommendationsfor,113 storagefor,99–107 troubleshooting,359,360 Restoringpreviousversion,32 Retirementphase(VirtualService Offeringslifecycle),212 Returnoninvestment,calculating, 421–422 Richdesktopusers,247 Roaminguserprofiles,302,307–309 Role-basedapplications,inPASS model,236 RPs(seeResourcepools) RSASecurID,250 RSAT(RemoteServerAdministration Tools),411 Runningstateofapplications, installationof,273
▼
S
SAN(seeStorageareanetworks) SAN(SubjectAlternateName) certificates,349 SATA(serialadvancedtechnology assessment)disks,195 Scalability: withclustering,383 ofvirtualappliances,221 Scalingout,107–108 Scalingup,107,108 Scenarios: fordesktopvirtualization,243–246 forservervirtualization,158–160 SCOM(seeSystemCenterOperations Manager) SCOPEclassificationtool,213–215 SCVMM(seeSystemCenterVirtual MachineManager) Searchengine,278 Securefilesystems,335–336 SecureSocketsLayer,346,348–349 SecureSocketsTunnelingProtocol (SSTP),349 Secureuseridentification,343 SecurID(RSA),250 Security: withAppV,284 forconsoleservers,333–334 desktop,234 forhostservers,332–333 keyelementsin,315 traditionalapproachesto,314 withvirtualappliances,221 (SeealsoInfrastructuresecurity) Securityscan,forlaboratories,148 Seedvirtualmachines: creating,216 provisioningwith,216–217 Segregatedsecuritycontexts,318 Semi-automatedP2V,223
Index
Serialadvancedtechnologyassessment (SATA)disks,195 SerV(seeServervirtualization) Server(VMware),34 Serverbases,110 Serverconsolidationstudy,85–88 Serverprocessors,comprehensive analysisof,67–69 Serversecurity,331 Serversprawl,4–5 Servervariance,110 Servervirtualmachines,protection of,328 Servervirtualization(SerV),25,154–191 benefitsof,37–38 bestpracticesin,207 choosingtechnologyfor,155–185 Citrixtechnologiesfor,173–176 decisionprocessfor,194–197 market-leaderhypervisormetrics, 187–191 Microsofttechnologiesfor,176–180 models,32–34 reasonsfor,14 scenariosfor,158–160 technologypricing,185–187 vendors,34–37 VMdisktypes,182–185 VMformats,180–182 VMwaretechnologiesfor,161–173 (SeealsoHypervisors) Server-basedcomputing(see Presentationvirtualization) Server-hostedDesktopVirtualization,241 Servers: categorizingrolesandfunctions of,21–23 laboratoryrolesfor,129–132 multiprocessing,111 newserverformfactors,53–55 protecting,373 unsuitedforvirtualization,92–93 Windows,4,5 (SeealsoHostservers)
Servicelevelagreements(SLAs),212, 396–397 Sharedcontent,protectionof,328 Sharedstorage,48–49,72–73,102(See alsoResourcepools) 64-bit,moveto,46–48 Single-VMhosts,204–206 SiteRecoveryManager(SRM),398–400 Site-baseddisasters,preparingfor,401 SLAs(seeServicelevelagreements) Snapshots,184,381 SnapSure,253 Socialenvironment,protecting,330 SoftGrid,291 SoftV(seeSoftwarevirtualization) SoftwareasaService,280–281 Softwaredevelopment,159 Softwarelicensing,135 Softwarepackaging,270–271,280 Softwarevirtualization(SoftV),25, 32–33,156 freeproducts,195 productsfor,157 SoftwareVirtualizationSolution (Symantec,SVS),42,256,291 Sourceservers,216 Specialworkloads,215 SQLServer: securitybestpractices,330 WFCSfor,378 SRM(SiteRecoveryManager),398–400 SSTP(SecureSocketsTunneling Protocol),349 StageManager(VMware),124,170,197 Stagingsecurity,331 Stagingtestinglevel,122,129,130, 133,136 Standardization,ascoreprocess,216 StandardizedstageofITmaturity, 154,155 Startupblocks,281 Statefulvirtualdesktops,245 Statelessvirtualdesktops,246,298 SteelEye,377
437
438
Virtualization: A Beginner’s Guide
Storage: EMCCelerrafor,253 forlaboratories,136 Storageareanetworks(SAN),72,73,99 bootingfrom,117 replicationcapabilitiesfor,377 andstorageconfiguration,106 storageconfigurations,102–103 Storageconfigurations,99–107 backupplan,106 best-in-breed,106–107 preparing,102–103 virtualizingstorage,103–107 Storageconsolidationstudy,70–73 Storagecontainers,protecting,372, 375–377 Storagelayer,56 Storagestrategy,112 Storagevirtualization(StoreV),27, 103–107 StorageVMotion,167–169,376 StoreV(seeStoragevirtualization) Streamingtechnologies,41–42 applications,256,273,274,281–283 desktops,256,298 SubjectAlternateName(SAN) certificates,349 Sun,35,135 Supportability,withvirtualappliances,221 Surveillanceprogram,331 SVS(seeSoftwareVirtualization Solution) SVSPro(Symantec),291–292 Symantec(company),225 Symantectechnologies: applicationvirtualization,293 SVS,42,256 SVSPro,291 SysPrep(SystemPreparationTool),257 SysPrepmachines,135 SystemCenterApplication VirtualizationStreamingServer,291 SystemCenterDataProtectionManager (Microsoft),413
SystemCenterOperationsManager (SCOM),16,413 SystemCentertools(Microsoft),412–414 SystemCenterVirtualMachineManager (Microsoft,SCVMM),89,130–131,177, 202–204,413 directoryservicehardening, 338–339 P2Vconversion,230 SystemPreparationTool(SysPrep),257 Systemprotectionstrategies,356–368 AppVas,273 CitrixXenServer,361–362 dataprotectionforVirtualService Offerings,366–367 hypervisormanufacturerofferings, 359–366 keyelementsfor,356 MicrosoftHyper-V,362–366 selectingthird-partybackuptools, 367–368 standardsystemrecovery strategies,357–359 VMwareConsolidatedBackup, 359–361 (SeealsoInfrastructuresecurity) Systemrecovery,356–359 Systemstack: AppV,275–276 “bull’seye,”298 fordesktopvirtualization,234–237 Systemtesting,158–159
▼
T
TCOCalculator(seeTotalCostof OperationsCalculator) TCO/ROICalculator(VMware),81 TechNetPlus,135 Technologypricing,185–187 Templates,VM,215 TenCommandmentsofAppV,295 Teradici,247,255
Index
Terminalservers,22,198 TerminalServices,29,34,137,253,297 Testingenvironments,195–197(Seealso Laboratories) Testinglevels,122–124 Testingphase(VirtualServiceOfferings lifecycle),212 TestingVMs,protectionof,328 Thawte,349 Thinclients,39 ThinApp(VMware),34,42,292 ThinStall,292 Third-partytools: backup,367–368 management,414–417 time-controlledvirtualPCimages,40 TotalCostofOperations(TCO) Calculator,81,170 TradeOffTools(APC),75,76 Training,159 TrangoVirtualProcessors(VMware),29 Transitive,29 Transparentpagesharing,164 Transportability: ofvirtualappliances,222 ofvirtualmachines,328 Trigence,29 Troubleshootingtechniques,standard, 358–359
▼
U
Ultimate-P2V,229 Undoabledisks,32,183 Unittestinglevel,122,129,132,133 UniversalSerialBus(USB),93 UNIX,5 Unmanageddesktopvirtualization, 244–245 Unmanagedproductusage,241 UpdateManager(VMware),217,340–341 Updating,219 USB(UniversalSerialBus),93
USBports,virtualizationof,93 Useraccounts: andpersonalityprotection,300 forvirtualmachines,129 Userdatalayer(desktops),238,239 Users: administrativerightsof,213 desktoprightsof,234 identifying,246–248 Utilitydirectories,337,339
▼
V
ValuetoBusinessBarometer,215 VAPs(seeVirtualappliances) VAS(VirtualAccessSuite),262 VDI(seeVirtualdesktopinfrastructure) VDM(seeVirtualDesktopManager) VECDlicense(seeVistaEnterprise CentralizedDesktoplicense) Verisign,349 VGC(VMwareGuidedConsolidation), 18–19 VHD(seeVirtualharddisks) VHDMount(Microsoft),367 View(VMware),253–258 VirtualAccessSuite(Quest,VAS),262 Virtualappliances(VAPs),218–223 benefitsof,221–222 creating,222–223 defined,30,218 selecting,219–220 Virtualapplications,highlyavailable, 392–394 Virtualarchitecture,370–371 Virtualdesktopinfrastructure(VDI),34, 240,248–249 highlyavailable,391 profitfrom,262–264 VirtualDesktopManager(VMware, VDM),250–256 Virtualdesktops,highlyavailable, 387–392
439
440
Virtualization: A Beginner’s Guide
VirtualDiskDevelopmentKit (VMware),367 Virtualdiskdrives,protecting,328–329 Virtualharddisks(VHD),31,183 VirtualInfrastructure(VMware),34,161, 165–173,250 VirtualIron,35,135,161 Virtuallayer,56 Virtuallayer,clusteringin,58 Virtuallocalareanetworks(VLANs), 95–96 Virtualmachinedisks(VMDK),31, 180–182 VirtualMachineFileSystem(VMFS), 101,102,375 Virtualmachine(VM)software,24, 124–125 Virtualmachinestatefile,32 Virtualmachines(VMs),30–32 configurationsforlaboratories, 127–128 decisionprocessforcreating, 194–197 disktypes,182–185 filetypes,31–32 formats,180–182 IPaddressesfor,96 licensing,135 managementof,59–60 protecting,373 seed,216–217 assetsoffiles,34 useraccounts,129 VirtualModemPro,93 Virtualnetworkswitches(VNS),97 VirtualPC(Connectix),176 VirtualPC(Microsoft),34,176 VirtualPrivateNetwork,349 VirtualServer(Microsoft),34,176 VirtualServer2005MigrationToolkit (Microsoft,VSMT),229 VirtualServiceOfferings(VSO),28 clusteringin,381–387 dataprotectionfor,366–367
defined,30 layersofprotectionfor,323–327 lifecycle,210–213 perimeternetworksfor,346–347 protecting,380–387 securityfor,317–318,322–327 structureof,197–100 troubleshooting,359,360 VirtualCenter(VMware),155,165,410 Virtual-DPlatform,261 Virtualization,4–7 defined,23 driversof,6 five-stepprocessfor(seeFive-step virtualizationprocess) forgreenerdatacenters,8–11 layersof,25–30,56–57 planningfor,5–7 rebatesfor,8–9 typesof,25–30 Virtualizationdecisionflowchart,60–61 VirtualizationEnergyCostCalculator, 77–79 Virtualizationlayer,273–281 Virtualizationstep(invirtualization process),23–43 applicationvirtualization,40–43 definingvirtualization,25–30 desktopvirtualization,38–40 servervirtualizationmodels,32–34 servervirtualizationvendors, 34–38 virtualmachines,30–32 Virtuozzo(Parallels),161 Visio(Microsoft),15,16 VistaEnterpriseCentralizedDesktop (VECD)license,241,242 VLANs(virtuallocalareanetworks), 95–96 VMsoftware(seeVirtualmachine software) VMDK(seeVirtualmachinedisks) VMFS(seeVirtualMachineFileSystem) VMotion,58,167,168
Index
VMs(seeVirtualmachines) VMsafe,335 VMwareCorporation,8,25,155,176,247 VMwaretechnologies,34,157 applicationvirtualization,292,293 CapacityPlanner,20 ConsolidatedBackup,166,359–361 Converter,226–228 fordesktopvirtualization,250–256 desktop-based,156 ESXServer,161–165 ESXi,33,35,161–165 GuidedConsolidation,18–19 LabManager,131–132 MobileVirtualizationPlatform,29 OpenVirtualizationFormat (OVF),180 forpolicy-basedresource management,408–410 popularityof,6 pricingcomparedtoothervendors, 185–187 replication,398 Server,34 serverassessmenttools,18–20 servervirtualizationsolutions,7 servervirtualizationtechnologies, 161–173 StageManager,124 TCO/ROICalculator,81,170 ThinApp,34,42,292 TrangoVirtualProcessors,29 VDIsolutions,249 View,253–256 VirtualDesktopInfrastructure,34 VirtualDesktopManager,250–256 VirtualInfrastructure,34,165–173 virtualmachinedisks,31 Workstation,34 (Seealsospecificapplications) VNS(virtualnetworkswitches),97 Volatiledesktops,249,298 Volatilepersistentdesktops,251
VolumeShadowCopyService(VSS),12 Volumesnapshots,highavailability for,381 VSMT(VirtualServer2005Migration Toolkit),229 VSO(seeVirtualServiceOfferings) VSS(VolumeShadowCopyService),12
▼
W
WAIK(WindowsAutomatedInstallation Kit),230 WFCS(WindowsFailoverCluster Service),378 WindowsAutomatedInstallationKit (WAIK),230 WindowsFailoverClusterService (WFCS),378 WindowsFileSystemResource Manager,70 WindowsInstallerservice (Microsoft,WIS),14–15,258–270 WindowsNT,4,89,94 Windowsoperatingsystem,4,5 AppVandindependenceof versions,277 problemswith,266 (Seealsospecificversions) WindowsResourceProtection,269 WindowsServer(Microsoft),6,33,71, 72,125,176,177,186–187 AutomatedDeployment Services,229 clusteringservices,382 DistributedFileSystem,392 FailoverClustering,375–377 PresentVfeaturesof,272 securityfor,333–334 WindowsServerFirewallwith AdvancedSecurity(WSFAS),347–348 WindowsServerUpdateServices (WSUS),341
441
442
Virtualization: A Beginner’s Guide
WindowsVista,14,16,237,269,303–307 WindowsXP,237,303 WIS(seeWindowsInstallerservice) Workloadvirtualization,194–207 resourceallocationrulesfor, 200–207 VirtualServiceOfferingsstructure, 197–100 Workloads: categorizing,22 laboratory,124 policy-based,30,404–408 SCOPEclassificationof,213–215 Workspaces,physicalvs.logical,125 Workstation(VMware),34,198 Workstations: inlaboratories,126–127 laboratoryrolesfor,129–132 fortestersanddevelopers,195–197 WSFAS(WindowsServerFirewallwith AdvancedSecurity),347–348 WSFC-aware,383
WSFC-incompatible,384 WSFC-independent,383 WSUS(WindowsServerUpdate Services),341 WyseTechnology,247,255
▼
X
XenApp(Citrix),34,41,290 XenCenter(Citrix),329,411 XenDesktop(Citrix),34,249,253, 256–260,391–392 XenMotion,58 XenServer(Citrix),7,34,35,173–175,375 businesscontinuity,377 directoryservicehardening,338 operatingsystemhardening,341 protectionstrategiesfor,361–362 securityfor,333 XenSource,173–174 Xerox,25