Often when you first create a Virtual Machine using VirtualBox, you set quite  a small size hard drive and you end up using this Virtual Machine far more than you expected.  All of a sudden you are running out of disk space, and you didn’t create a dynamic disk that increases automatically… Below are the steps to increase the size of your Windows Virtual Machine in VirtualBox.

  1. First you need to shutdown the Virtual Machine for the change to work, which makes sense.  Imagine upgrading a physical machine without shutting down.
  2. Using Terminal (on a Mac) cd into the directory where your virtual drive is found (usually ~/VirtualBox VMs/{Your VirtualBox name})
    cd ~/VirtualBox\ VMs/WinServer
  3. run the modifyhd command with the new size (in MB) I choose 80GB (80 * 1024mb = 81920MB)
    VBoxManage modifyhd WinServer.vdi --resize 81920
  4. VirtualBox will resize your hard drive and you will see the following output from the system indicating that the process is complete:
  5. Now start up your Windows Virtual Machine. Log in, on Server editions open ‘Server Manager’.  On client, right-click on ‘Computer’ and choose ‘Manage'.
  6. Click on the Disk Management option on the left panel (in Windows Server editions, this is found under ‘Storage’). You will notice some black space next to your C drive (this means the space addition was successful.)
    Screen shot of additional allocated hard drive space
  7. Right Click on the C drive and choose ‘Extend Volume'. Follow the wizard (Next, Next, Finish) and you have successfully increased the size of your VirtualBox disk.
    Select to Extend the volume to increase the VirtualBox hard drive size
    The hard drive has now increased in size
    Drive C is shown to now of been increased/expanded
Share →

10 Responses to Increase VirtualBox Hard Disk Size

  1. Tony says:

    After hours of frustration trying to fix this situation yours was the only solution that worked. Thank You!

  2. melanei says:

    Finally! That was the easiest instruction that really works! Too bad I deleted most of my files before finding your site!
    Thank you very much! :)

  3. Tom Krause says:

    I’ve been trying for hours. Get the following message

    Progress state: VBOX_E_NOT_SUPPORTED
    VBoxManage: error: Resize hard disk operation for this format is not implemented yet!

    any help gratefully received


    • Sam says:

      Hi Tom,
      It might be a fixed size disk? Which I believe isn’t supported to be resized. What you can do, however, is clone the fixed size disk into a Dynamic disk then resize it.
      VBoxManage clonehd Win7.vdi Win7Dynamic.vdi
      VBoxManage modifyhd –resize 80960 Win7Dynamic.vdi
      Then attach this new dynamic disk to your VM.
      Kind regards,

      • Nick says:

        Hi Sam,

        I have a Windows 7 fixed disk that I’m trying to resize and tried your suggestion here. The Win7Dynamic.vdi file was created within the Win7 VM folder. At this point, I’m stuck and can use your guidance. When you say, “Then attach this new dynamic disk to your VM”, how is this done?

        Thank you!

        • Sam says:

          Hi Nick,
          Thanks for your comment. Sorry it has taken me a while to get back to you.
          To attach the new disk to the VM, open the VirtualBox GUI, select your VM (make sure it is shutdown) and edit the Settings. Then on the Storage tab select the .vdi from the left and then utilising the little hard drive icon to browse, select “Choose a virtual hard disk file…” and select your new .vdi. OK/Close out of everything then just start up your machine.
          Hope this helps. I’m happy to take some screenshots and update the article if you wanted – if I get the time I may do this anyway.
          Kind regards,

  4. Adrianna says:

    Thank you so much!! This worked fantastically! I’m so glad I didn’t have to resort to just making a new virtual machine.

Leave a Reply

Your email address will not be published. Required fields are marked *