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VMware ACE Administrator’s Manual
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.
If you chose to allocate space for the virtual disk in advance, the file sizes are fixed, 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 did 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 first file’s name.
For example, a Windows XP Professional virtual machine using the default
configuration, with files that grow as needed, stores the disk in files named Windows
XP Professional.vmdk, Windows XP Professional-s001.vmdk,
Windows XP Professional-s002.vmdk and so on.
Lock Files
A running virtual machine creates lock files to prevent consistency problems on
virtual disks. If the virtual machine did not use locks, multiple virtual machines might
read and write to the disk, causing data corruption.
Lock files are always created in the same directory as the .vmdk file.
The locking methods used by VMware software on Windows and Linux hosts are
different, so files shared between programs running on the two platforms are not fully
protected. If you use a common file repository that provides files to users of VMware
products on both Windows and Linux hosts, be sure that each virtual machine is run
by only one user at a time.
When a virtual machine is powered off, it removes the lock files it created. If it cannot
remove the lock, a stale lock file is left protecting the .vmdk file. For example, if the
host machine crashes before the virtual machine has a chance to remove its lock file, a
stale lock remains.
If a stale lock file remains when the virtual machine is started again, the virtual
machine tries to remove the stale lock. To make sure that no virtual machine could be
using the lock file, the virtual machine checks the lock file to see if
1. The lock was created on the same host where the virtual machine is running.
2. The process that created the lock is not running.