VirtualBox VBOX_E_NOT_SUPPORTED Drive Resize Errorby on April 4 2012
Need more space for your virtual box? No problem right? But you’re scratching your head with this VBOX_E_NOT_SUPPORTED … format is not implemented yet! error?
Turns out you’re not alone. I had this very annoying error message when I was trying to resize a VirtualBox virtual drive. It’s nice that VirtualBox included a built-in command for this task but the error left me scratching my head. I was trying to resize a virtual drive to 8 gigabytes using the following convenient built-in command:
VBoxManage modifymedium --resize 8096 <path_to_your_vbox_drive>.vdi
and I got:
Progress state: VBOX_E_NOT_SUPPORTED
VBoxManage: error: Resize hard disk operation for this format is not implemented yet!
Update 2016/02/03: VirtualBox seems to have renamed the command from modifyhd to modifymedium. Therefore, you may need to adapt these instructions depending on your VirtualBox version.
I wasn’t really sure what VirtualBox was referencing. Turns out it’s the VirtualBox drive type that isn’t supported. More specifically, VirtualBox does not support resizing a fixed-size virtual disk. Therefore, you can only resize a dynamically-resizing virtual drive. There is a quick solution if you don’t mind the new drive being dynamic. Turns out that VirtualBox’s virtual drive cloning tool will take your fixed-size virtual drive and when cloning, create you a copy but as a dynamic drive. To do this, simply execute the following commands:
Make sure you’ve made a backup before you attempt these changes.