How to Expand a VM Disk with VMWare

How to Expand a VM Disk and merge it into the existing partition.

If you have created a VM with VMWare Workstation/Server and have since discovered you need more disk space within the VM, use the vmware-viskmanager command utility together with a partition tool, here is how I do it!!

Use the vmware-vdiskmanager command line tool to expand the current VMware disk file. Your virtual disk file may look something like this “ws2003.vmdk”. Let’s say that the current disk size is 8GB and you want to make it 15GB, run the following command:
“vmware-vidiskmanager.exe -x 15GB ws2003.vmdk”
See the syntax switches from the Administration Manual or issue vmware-vdiskmanager.exe /? for more.

Once you have expanded the disk file you will need to use a disk partition tool to merge the partitions or if you are happy with a second partition simply use the Disk Manager tool from the Administration Tools in Windows XP or Windows 2000/2003.

To Merge the parition I recommend BootIT from Terrabyte – see for more details.

With VMWare you may be unable to see the screen once booting into BootIT, this problem can occur when the video adapter chipset is not supported.

To work around this issue:

  • First try reversing the VESA Video option when you create the installation diskette (that is, if you had it enabled before, try leaving it disabled, or vice versa).
  • If it still does not work, try doing the same with the Standard VGA option.
  • You may need to upgrade your system BIOS and/or graphics card firmware.