I have virtualbox-4.1.0 with centos-5.6 installed in. Now I would like to extend the VM image, which I previously allocated for virtual machine installation, it was 8Gb, that\'s
From the VirtualBox FAQ:
You have to clone the data from the VDI you already have to a new, larger VDI and expand the partition(s). You can use tools like CloneZilla to clone the virtual hard drive to the bigger one and Gparted to increase the partition size. Another method is to use CloneVDI by mpack and clone the VDI with a larger size, then resize the partition(s) with Gparted.
Since 4.0.0, you can use VBoxManage modifyhd --resize to resize the max size of the VDI. You can only make it bigger. After that, use Gparted to increase the partition size inside the VDI.
Alternatively you could attach another VDI and mount your /home there.