Specifications

VMware, Inc. 235
Chapter 15 Migrating Virtual Machines
processorsmustcomefromthesamevendorclass(IntelorAMD)andsameprocessor
family(P3,P4,orIntelcore)tobecompatibleformigrationwithVMotion.
ProcessorfamiliessuchasIntelXeonandAMDOpteronaredefinedbytheprocessor
vendors.
Youcandistinguishdifferentprocessorversionswithinthesamefamily
bycomparing
theprocessors’model,steppinglevel,andextendedfeatures:
 Inmostcases,differentprocessorversionswithinthesamefamilyaresimilar
enoughtomaintaincompatibility.
 Insomecases,processorvendorshaveintroducedsignificantarchitectural
changeswithinthesameprocessorfamily,suchastheSSE3andSSSE3instructions,
andNx/XDCPUsecurityfeatures.Bydefault,VMwareidentifiesmismatcheson
SSE3,SSSE3,andNx/XDasincompatibletoguaranteethestabilityofvirtual
machinesaftermigrationswithVMotion.
Server
hardware’sCPUspecificationswillusuallyindicatewhetherornottheCPUs
containtheSSE3,SSSE3,andNx/XDfeaturesthataffectVMotioncompatibility.Ifthe
specificationsofaserveroritsCPUfeaturesareunknown,VMware’sbootableCPU
identificationutility(availablefordownloadwithESXServer)canbeusedtoboota

serveranddeterminewhetheritsCPUscontainfeaturessuchasSSE3,SSSE3,and
NX/XD.
Nx/XD Considerations
 AMD’sNoeXecute(NX)andIntel’seXecuteDisable(XD)technologyservethe
samesecuritypurpose:tomarkmemorypagesasdata‐onlytopreventmalicious
softwareexploitsandbufferoverflowattacks.
 ThefollowingoperatingsystemssupportNXandXD:
WindowsServer2003(SP1),Windows*XP(SP2),WindowsVista,RHEL4,RHEL3
(Update3),SUSE10,SUSELinux9.2,Solaris10,Linuxkernels2.6.6orlater(or2.4
kernelswithapatch).
 InESXServer3.0,NXandXDtechnologyisexposedbydefaultforallguest
operatingsystemsthatcanuseit(tradingoffsomecompatibilityforsecurityby
default).HostspreviouslycompatibleinESXServer2.xmightbecome
incompatibleafterupgradingtoESXServer3.0ifNXmismatched,butper‐VM

CPUcompatibilitymasksspecifiedintheVMotionCPUCompatibilityMatrixcan
beusedtorestorecompatibility.
N
OTEVMware,inpartnershipwithCPUandhardwarevendors,isworkingto
maintainVMotioncompatibilityacrossthewidestrangeofprocessors.Foradditional
information,checktheVMwareKnowledgeBase.