Specifications

VMware, Inc. 131
Chapter 6 View Composer
Averyaggressivelevelofstorageovercommitresultsinarelativelysmallamountof
spacebeingreservedfordeltadiskexpansion;however,administratorscanaddalotof
extravirtualmachinestothedatastoreiftheypredictthatthedeltadisksofeachvirtual
machinewillnevergrowtotheirmaximum
possiblesize.
Whileahighovercommitlevelmaybeoptimalforcreatingalargenumberofvirtual
machines,adesktoppoolofthistypealsodemandsmoreattentionfromthe
administratorinordertoensurethattheremainingdiskspaceisnotcompletely
consumedbyvirtualmachineexpansion.Thisconditioncan
bepreventedby
periodicallyrefreshingorrebalancingthedesktoppoolandreducingthesizeofthe
operatingsystemdatatoitsbaselinelevel.
Toaddressdifferentlev elsofthrough putoneachdatastore,youcanvarystorage
overcommitlev elsbetweendifferenttypesofdatastores(forexample,NASversusSAN).
Storageovercommitapplies
onlytodeltadisks.Itdoesnotapplytouserdisksor
standard(non‐linked)clones.
Desktop Recomposition
InFigure 6‐2adesktopcloneislinkedtoreplica1,whichitselfisacopyofParent VM 1.
Arecompositionactionisinitiatedwhentheadministratorselectsadifferentsnapshot
inthesameParentVMordifferentParentVM(asinthisexample).Ineithercaseanew
replicaisprovisioned.
Figure 6-2. Desktop Recomposition
base image + snapshot
bloated
OS data disk
refreshed
OS data disk
user data disk
user data disk
replica 2—
new base image
after recomposition
replica 1
parent VM 1
base image + snapshot
parent VM 2
recompose