2.0

Table Of Contents
VMware Server User’s Guide
284 VMware, Inc.
Using DMA in Windows NT Guests on Multiprocessor Host
Systems
YoumightexperienceslowerthanexpecteddiskI/OperformanceinWindowsNT
guestoperatingsystemswhenusingIDEvirtualdisksonmultiprocessorhost
computers.TheI/Olimitationisespeciallynoticeablewhenthevirtualmachineis
booting.YoucanincreaseperformancebyenablingDMAonthevirtualdisk’sIDE
channel.
Ifyou
haveavirtualdiskandaCD/DVDattachedasmasterandslavetotheprimary
IDEcontroller(channel0)andyouwanttoenableDMA,poweroffthevirtualmachine
andedittheCD/DVDdrivetomoveittothesecondaryIDEcontroller(channel1)at
IDE1:0.
Youcan
enableDMAafterinstallingWindowsNTServicePack3orhigher.Inthe
WindowsNTguest,insertanSP3orSP4CDinthedriveandrunDMACHECK.EXEfrom
the\SUPPORT\UTILS\I386folderontheCD.Alternatively, downloadDMACHECK.EXE
fromtheMicrosoftWebsite:http://support.microsoft.com/kb/q191774/
ClicktheEnabledoptionfortheIDE
controllerandchannelconfiguredforthevirtual
disk.Typically ,thisischannel0only,unlessyouhavethevirtualmachineconfigured
withmultiplevirtualdisksandnovirtualCD/DVDdrive.
DonotenableDMAonanIDEchannelwithavirtualCD/DVDdriveattached.
Monitoring Virtual Machine Performance on Windows Hosts
VMwareServerprovidesasetofcountersthattheMicrosoftPerformanceconsolecan
usetocollectperformancedatafromrunningvirtualmachines.
ThePerformanceconsoleisavailableonlyonWindowshosts.However,youcan
monitortheperformanceofanytypeofguestoperatingsystem,includingLinux
guests.
TheVMwareServerperformancecounters
canmonitorthefollowingdatafroma
runningvirtualmachine:
Readsandwritestovirtualdisks
Memoryusage
Virtualnetworktraffic
Youcantrackvirtualmachineperformanceonlywhenavirtualmachineisrunning.
Theperformancecountersreflectthestateofthevirtualmachine,nottheguest
operatingsystem.Forexample,thecounterscandeterminehowoftentheguestreads
fromavirtualdisk,butcannotdeterminehowmany
processesarerunningintheguest.