Tom Lauck’s

Expanding a Parallels Disk Image…What They Don’t Tell You


On the initial install of Windows XP under Parallels, I was very conservative in the disk space I allocated to it. After Windows repeatedly yelling at me to do something about the lack of disk space I figured I would.

When setting up the Windows Virtual Machine, I had the image set to “Expanding.” A bit deceiving…for there is a procedure that is not “included” in the help file for accomplishing this:

  1. Find your hard disk image file on the host machine (in this case Mac OS).. Run the Parallels ImageTool on it and expand it to the desired amount.
  2. Duplicate the hard disk image you wish to expand on the host machine.
  3. Open Parallels then the preferences for the virtual machine you are using. Change the hard disk image path the duplicate image.
  4. Add a new hard disk via the add button and add a new hard disk. Set the path to the original image…the purpose of this and the above step is to boot from the duplicate disk so that Windows can have full access to the disk (original image) you wish to expand.
  5. Boot up Windows. Then navigate to Start->Run. Enter “DISKPART” and press Run/Enter.
  6. In the new window that appears type: “list volume”
  7. After that process runs, a list of disks appears. Notice that Volume 1 and Volume 2 look identical. *Note: Volume 2 should be the original hard disk image.
  8. Select Volume 2 by typing: “select volume 2″ then extend it by typing “extend” once that is complete type “exit” and shut down Windows.
  9. Clean up the Virtual Machine preferences by deleting the second hard disk and switching the hard disk 1 path back to the original hard disk image.
  10. Restart Windows. Rebooting may be necessary if Windows “detects new hardware.”

This procedure allows Windows to see the extra space that Parallels has allocated. One day maybe Windows will be easier to use……if hell freezes over.

Dec 1 2006