Virtual hard disk not expanding in Hyper-V RRS feed

  • Question

  • Hi all,

    I am running Hyper-V on Windows Server 2008. I installed a domain controller on a virtual machine. I provided a dynamically expanding disk drive. As it turned out, I needed a bigger hard disk. I edited the hard disk while the virtual machine was turned off, but for some reason the new size (16 GB to 32 GB) is not reflected in the virtualized Windows environment. In Hyper-V, the drive is indeed 32 GB. However, when in Explorer on the virtual machine itself, it is still limited to 16 GB. I tried to change it to a fixed size drive, but this didn't help me either. I converted the drive again to a dynamically expanding drive again. Has anyone had experience with this? I really don't get why the new size of the disk is not being noticed by the guest OS (domain controller on Windows Server 2008 64 bits).


    Sunday, October 25, 2009 9:38 PM


All replies

  • Check out this blog:
    Essentially you will need to start up the VPC thern go into disk manager and extend the volume.
    • Marked as answer by r.heinkens Tuesday, March 23, 2010 9:12 PM
    • Marked as answer by r.heinkens Tuesday, March 23, 2010 9:12 PM
    Thursday, December 10, 2009 6:43 PM
  • Thanks, that helped me.
    Computer Science Made Easy
    Tuesday, March 23, 2010 9:12 PM
  • Good morning,

    I essentially have the same problem with Server 2003.

    Where in the Disk Manager in the VPC  can I extend the volume ...?!

    There does not seem to be any options other than changing the drive letter!



    Bahram Saghari

    Tuesday, July 27, 2010 6:18 PM
  • Just making sure: I am using Diskpart.exe to extend the volume but it keeps giving me the error message: The volume you have selected may not be extended. Please select another volume and try again.



    Bahram Saghari

    Tuesday, July 27, 2010 8:52 PM
  • I have only done this so far where the host machine is Windows Server 2008 R2 but:

    Rather than use Diskpart.exe, I typed "Disk Management" (note: not "Disk Manager") after clicking Start. Alternatively, you can type "Create and format hard disk partitions" to get to the same UI tool. From here I successfully extended the volume to use the unallocated space (which was provided after increasing the limit of the dynamically expanding disk on the host machine) [and I agree is silly that this doesn't auto-happen or provide heads up that this needs to be done].

    Edit: Found a guide where it notes that you cannot use Diskpart.exe or Disk Management for Windows 2008/XP/2003.

    Expanding Virtual Hard Disks with Hyper-V:
    While possible in Windows Server 2008 and Windows Vista, unfortunately, in Windows 2000/XP/2003, you cannot use the built-in tools to expand the System Partition (the one the Windows operating system is installed on). For these versions you will need to use of these free partition utilities.

    • Edited by Ashley Myers Tuesday, March 27, 2012 8:18 PM minor clarification, addition of information
    • Proposed as answer by coolYo Sunday, August 25, 2013 3:34 AM
    • Unproposed as answer by coolYo Sunday, August 25, 2013 3:34 AM
    Tuesday, March 27, 2012 7:37 PM
  • this is the ANSWER

    Wednesday, May 20, 2015 8:56 PM
  • Thanks man, i feel dumb now but the drive is fixed lol. :)
    Thursday, October 22, 2015 12:52 PM