virtualbox cant scale to full screen code example
Example 1: how to increase the screen size in virtualbox
sudo apt-get install virtualbox-ose-guest-utils virtualbox-ose-guest-x11 virtualbox-ose-guest-dkms
Example 2: virtualbox fullscreen resolution
sudo apt-get install virtualbox-guest-dkms
sudo dpkg-reconfigure virtualbox-guest-dkms