Specifications

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VMware GSX Server Virtual Machine Guide
The first .vmdk file for each disk is small and contains pointers to the other files that
make up the virtual disk. The other .vmdk files contain data stored by your virtual
machine and use a small amount of space for virtual machine overhead.
By default, all disk space is allocated when you create the virtual disk. A preallocated
virtual disk has fixed file sizes, and most of the files are 2GB. As mentioned above, the
first file is small. The last file in the series may also be smaller than 2GB.
If you chose to not allocate the space in advance, the .vmdk files grow as data is
added, to a maximum of 2GB each — except for the first file in the set, which remains
small.
The virtual machine settings editor shows the name of the first file in the set — the
one that contains pointers to the other files in the set. The other files used for that disk
are automatically given names based on the name of the first file.
For example, a Windows 2000 Server virtual machine using the default configuration,
with files that grow as needed, stores the disk in files named Windows 2000
Server.vmdk, Windows 2000 Server-s001.vmdk, Windows 2000
Server-s002.vmdk and so on.
If the disk space is allocated in advance and the virtual disk is split into 2GB files, the
names are similar, except that they include an f instead of an s — for example,
Windows 2000 Server-f001.vmdk. If the disk is not split into 2GB files, the
virtual machine stores the disk in two files, named Windows 2000
Server.vmdk and Windows 2000 Server-flat.vmdk.
If you are using a physical disk, the .vmdk file stores information about the physical
disk or partition used by the virtual machine.
Redo-Log and Snapshot Files
Redo-log files save blocks that the virtual machine modifies while it is running. The
redo-log file for a disk in independent-nonpersistent mode is not saved when the
virtual machine is powered off or reset, while the redo-log file for a disk with a
snapshot is saved. This file is known as the redo log.
The redo-log file for a virtual disk called vm is called vm.vmdk.REDO. If the virtual
disk is split into 2GB files, the disk files are named vm.vmdk, vm-02.vmdk,
vm-03.vmdk and so on; its redo-log files are called vm.vmdk.REDO,
vm-02.vmdk.REDO, vm-03.vmdk.REDO and so on.
When you take a snapshot of a virtual machine called vm, GSX Server stores the
snapshot in a file is called vm.vmsn. For more information about snapshots, see
Taking Snapshots on page 153.