How To Expand An Exisiting Virtual Disk In VMWare Server

Just like physical servers, Virtual Machines created with VMWare Virtual Server, may eventually run out of available disk space. With physical servers, the solution is to add more hard disks and move data or use third party tools to resize the partition. With Virtual Machines, you could also add virtual disks, but if you need to resize the partition, one solution is to use VMWare Server  built-in command line utility called vmware-vdiskmanager, that can create, rename, defragment, shrink and expand virtual disks.

To expand an existing partition, the Virtual Machine must be shutdown and powered off. The vmware-vdiskmanager utility resides in the directory that VMWare server was installed. On my install, it is located at C:\Program Files\VMware\VMware Server.

Open a command prompt and navigate to the directory of the virtual disk you want to expand, and execute a directory listing by typing dir at the command prompt.

C:\OTHER\Virtual Machines\WTN1>dir
 Volume in drive C is System
 Volume Serial Number is E40F-D10A

05/18/2007  05:30 PM    <DIR>          .
05/18/2007  05:30 PM    <DIR>          ..
05/18/2007  04:24 PM             8,664 nvram
05/14/2007  11:57 AM            21,751 vmware-0.log
05/14/2007  08:37 AM            20,180 vmware-1.log
05/12/2007  09:52 PM            22,807 vmware-2.log
05/18/2007  04:24 PM            19,519 vmware.log
04/02/2007  12:41 PM               850 Windows XP Professional.vmsd
05/18/2007  02:28 PM               856 Windows XP Professional.vmx
05/18/2007  04:24 PM     8,589,934,592 WTN1C.vmdk

On my Computer, the Virtual Machine is located at C:\OTHER\Virtual Machines\WTN1 and the Operating System is Windows XP Professional named WTN1. The virtual disk that needs to be expanded is WTN1C.vmdk.

The command to expand a virtual disk follows:

vmware-vdiskmanager -x <new-capacity> diskname

Where:

-x is the option to expand
<new-capacity> is the new size of the virtual disk you want to expand
diskname is the virtual disk name

(NOTE: enter the full path to the vmware-vdiskmanager executable. Use quotes if the path includes spaces)

C:\OTHER\Virtual Machines\WTN1>"C:\Program Files\VMware\VMware Server\vmware-vdiskmanager" -x 10GB WTN1C.vmdk
Using log file C:\Users\Owner\AppData\Local\Temp\vmware-Owner\vdiskmanager.log
Grow: 100% done.
The old geometry C/H/S of the disk is: 16383/16/63
The new geometry C/H/S of the disk is: 16383/16/63
Disk expansion completed successfully.

WARNING: If the virtual disk is partitioned, you must use a third-party
utility in the virtual machine to expand the size of the
partitions. For more information, see:
http://www.vmware.com/support/kb/enduser/std_adp.php?p_faqid=1647

Next, execute a directory listing to verify the virtual disk was expanded.

C:\OTHER\Virtual Machines\WTN1>dir
 Volume in drive C is System
 Volume Serial Number is E40F-D10A

 Directory of C:\OTHER\Virtual Machines\WTN1

You should now see the new size of the virtul disk. Also, notice the Warning message above. You will need to use a third party tool such as Partition Magic or Acronis Disk Director to resize the partition inside the Virtual Machine Operating System.

To list all available options for vmware-vdiskmanager, just enter the following at a command prompt:

vmware-vdiskmanager.exe /?