Specifications

Table Of Contents
VMware Server Virtual Machine Guide
120 VMware, Inc.
Disk Types: Virtual and Physical
In!the!most!common!configurations,!VMware!Server!creates!virtual!hard!disks,!which!
are!made!up!of!files!that!are!typically!stored!on!your!host!computer’s!hard!disk.!In!some!
circumstances,!you!might!need!to!give!your!virtual!machine!direct!access!to!a!physical!
hard!drive!on!your!host!computer!!using
!the!disk!type!referred!to!as!a!physical!disk.
Virtual Disk
A!virtual!disk!is!a!file!or!set!of!files!that!appears!as!a!physical!disk!drive!to!a!guest!
operating!system.!The!files!can!be !on!the!host!machine!or!on!a!remote!computer.!When!
you!configure!a!virtual!machine!with!a!virtual!disk,!you!can!install!a!new!operating
!
system!onto!the!virtual!disk!without!repartitioning!a!physical!disk!or!rebooting!the!
host.
IDE!virtual!disks!can!be!as!large!as!950GB.!SCSI!virtual!disks!can!be!as!large!as!950GB.!
Depending!on!the!size!of!the!virtual!disk!and!the!host!operating!system,!VMware!
Server!creates!one!or!more
!files!to!hold!each!virtual!disk.
By!default,!the!virtual!disk!is!configured!so!all!the!disk!space!is!allocated!at!the!time!the!
virtual!disk!is!created.!This!type!of!virtual!disk!is!known!as!a!preallocated!disk.!A!
preallocated!disk!provides!enhanced!performance!and!is!useful!if!you!
are!running!
performancesensitive!applications!in!the!virtual!machine.!A!virtual!disk!that!is!not!
preallocated!is!known!as!a!growable!disk.!A!growable!virtual!disk’s!files!start!out!small!
and!grow!to!their!maximum!size!as!needed.!The!main!advantage!of!this!approach!is!the!
smaller!file!size.!Smaller!
files!require!less!storage!space!and!are!easier!to!move!if!you!
want!to!move!the!virtual!machine!to!a!new!location.!You!can!shrink!this!type!of!virtual!
disk.!However,!it!takes!longer!to!write!data!to!a!disk!configured!in!this!way.
Virtual!disks!can!be!set!up!as!
IDE!disks!for!any!guest!operating!system.!They!can!be!set!
up!as!SCSI!disks!for!any!guest!operating!system!that!has!a!driver!for!the!BusLogic!SCSI!
adapter!used!in!a!VMware!Server!virtual!machine.!
NOTE To!use!SCSI!disks!in!a!Windows!XP!or!Windows!Server!2003!virtual!machine,!
you!need!a!special!SCSI!driver!available!from!the!download!section!of!the!
VMware!Web!site!at!www.vmware.com/download.!Follow!the!instructions!
on!the!Web!site!to!use!the!driver!with!a!fresh!installation!of!Windows!XP!
or!
Windows!Server!2003.!
A!virtual!disk!of!either!type!can!be!stored!on!either!type!of!physical!hard!disk.!That!is,!
the!files!that!make!up!an!IDE!virtual!disk!can!be!stored!on!either!an!IDE!hard!disk!or!a!
SCSI!hard!disk.!So!can!the!files!that!make!up
!a!SCSI!virtual!disk.!They!can!also!be!stored!
on!other!types!of!fastaccess!storage!media,!such!as!DVDs!or!CDROM!discs.!For!