virtualbox resize virtual 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

Go to the VirtualBox options while in your VM (the same place you went to to install Guest Additions) and select View -> Auto-resize Guest Display. This should automatically set your VM's resolution to the proper screen size.