Resizing a VirtualBox 4.2 virtual Hard Disk

Here a little how to increase the dimension of  VBox machine Hard Disk (ubuntu guest and host):

1. on a terminal host execute this command:

  $VBoxManage modifyhd 'YOUR_VDI_LOCATION' --resize SIZE_IN_MEGABYTES

      tips: for the size in megabyte go to Google  and type your desired size in gigabyte to be converted to megabyte. For example: 10 GB = MB –> the       result should be 10240.


2. then I needed to physically expand the partition of the virtual disk. To do this I used the software “gparted” in the guest machine running a live CD version of my distro.

For further information take a look here