This tutorial shows how to install the guest additions for Debian, Ubuntu, Linux Mint based systems that are running as Virtualbox virtual machine.
Guest Additions is an external package designed to be installed inside a VirtualBox guest OS. It enables closer integration between the host and guest OSes, including features such as shared folder, custom video drivers, seamless window mode, and more.
Guest Additions is not installed by default after installed your system as virtual machine. It’s however easy to install through the official CD image.