HOWTO: resize virtualbox vmdk file in windows

This description is based on stackoverflow answer and update to work under windows.

1. Clone

   "C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" clonehd "source.vmdk" "cloned.vdi" --format vdi
   

2. Resize to 30G (30*1024)

"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" modifyhd "cloned.vdi" --resize 30720

3. Clone back to vmdk

"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" clonehd "cloned.vdi" "resized.vmdk" --format vmdk