VBoxManage: error: Resize medium operation for this format is not implemented yet!

Problem

An .vdi image resize gives you an error:

$ VBoxManage modifyhd ./Win7N.vdi --resize 50000
0%…
Progress state: VBOX_E_NOT_SUPPORTED
VBoxManage: error: Resize medium operation for this format is not implemented yet!

Analysis

The VDI format of the image is not supported by resize function. Use the following command to find out more about the virtual image:

$ VBoxManage showhdinfo ./Win7N.vdi
UUID:           d53a....-....-....-....-....e772fcd2
Parent UUID:    base
State:          created
Type:           normal (base)
Location:       /home/.../VirtualBox VMs/Win7N/./Win7N.vdi
Storage format: VDI
Format variant: fixed default
Capacity:       31490 MBytes
Size on disk:   31493 MBytes
Encryption:     disabled

Solution

We can clone the image to do the job. Just do:

$ VBoxManage clonehd ./Win7N.vdi ./Win7N_dynamic.vdi

The default image format is dynamic so the newly created ./Win7N_dynamic.vdi image will have a dynamic format.

Notes

You may need to reattach and attach back your .vdi image. You may get a “Cannot register the hard disk” error. Check out the following post to sort out the problem:

• VBoxManage: error: Cannot register the hard disk ‘…’ because a hard disk ‘…/.vdi’ with UUID {…} already exists