Resize partition of Windows 7 running on VirtualBox with dynamically allocated storage

Question

I run Windows 7 inside VirtualBox.

I resized the disk of Windows 7 from 25 GB to 50 GB:

VBoxManage modifyhd Windows\ 7\ Pro.vdi --resize 50000
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%

PROBLEM: I can' grow the partition, neither with Windows 7 itself nor with GParted:

It looks like VirtualBox does not tell the client OS about the new size.
What additional step is necessary?

Solution

You can only resize disks if they are not part of a VM that uses snapshots.

If you are using snapshots, you can easily clone the state to a new VM and hard disk, and resize that one. VirtualBox 4 now supports cloning from the GUI, so it's super easy.

VBoxManage - modifyhd

Here's a helpful walk through of the whole process, Resize and Expand a Virtualbox Hard Drive and Media in 4 Steps

Comments

[dalf]

as Ryan said, my VM had snapshots and I couldn't extend the partition in Windows. I ended up cloning the VM (not just the disk). See command "vboxmanage clonevm". The clone contained only the current state (no snapshots), so I was able to extend the partition.

[Nicolas Raoul]

That works! Note: After cloning and resizing the disk, open the VM's settings, remove the former disk and add the new one.

[SuperSafie]

Also it seems to not be available for VMDK disk images