Specifications

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VMware GSX Server Virtual Machine Guide
Configuring Hard Disk Storage in a
Virtual Machine
Like a physical computer, a VMware GSX Server virtual machine stores its operating
system, programs and data files on one or more hard disks. Unlike a physical
computer, GSX Server gives you options for undoing changes to the virtual machine’s
hard disk.
The New Virtual Machine Wizard creates a virtual machine with one disk drive. You can
use the virtual machine settings editor (VM > Settings) to add more disk drives to
your virtual machine, to remove disk drives from your virtual machine or to change
certain settings for the existing disk drives.
The following sections describe the choices you can make in setting up hard disk
storage for your virtual machine.
• Disk Types: Virtual and Physical on page 162
• Additional Information about Disk, Redo-Log, Snapshot and Lock Files on
page 165
• Defragmenting and Shrinking Virtual Disks on page 168
Disk Types: Virtual and Physical
In the most common configurations, GSX 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 may 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 128GB. SCSI virtual disks can be as large as 256GB.
Depending on the size of the virtual disk and the host operating system, GSX 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
performance-sensitive applications in the virtual machine. Virtual disks created in this