Specifications

CHAPTER 6 Using Disks in a Virtual Machine
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Using VMware Virtual Disk Manager
VMware Virtual Disk Manager is a utility in GSX Server that allows you to create,
manage and modify virtual disk files from the command line or within scripts.
One key feature is the ability to enlarge a virtual disk so its maximum capacity is larger
than it was when you created it. This way, if you find you need more disk space on a
given virtual disk, but do not want to add another virtual disk or use ghosting
software to transfer the data on a virtual disk to a larger virtual disk, you can simply
change the maximum size of the disk. This is something you cannot do with physical
hard drives.
Another feature allows you to change whether or not all virtual disk space is
preallocated or growable, and whether or not the virtual disk is stored in a single file or
split into 2GB files. For example, you might find that you preallocated all the disk space
for a virtual disk, but need to reclaim some hard disk space on the host. You can
convert the preallocated virtual disk into a growable disk and remove the original
virtual disk file. The new virtual disk is large enough to contain all the data on the
original virtual disk. The virtual disk grows in size as you add data to it, as if you never
preallocated the disk space when you created the virtual disk.
These features and the ability to use scripting to automate management of virtual
disks were not possible with VMware products until now.
You can use the virtual disk manager to:
• Automate the management of virtual disks with scripts.
• Create virtual disks that are not associated with a particular virtual machine, to
be used for templates, for example.
• Switch the virtual disk type from preallocated to growable, or vice versa. When
changing the disk type to growable, some space on the virtual disk is reclaimed.
You can shrink the virtual disk to reclaim even more disk space.
• Expand the size of a virtual disk so it is larger than the size specified when you
created it.
• Defragment virtual disks.
• Prepare and shrink virtual disks without powering on the virtual machine
(Windows hosts only).
• Rename and move virtual disks.