Oracle VM VirtualBox : Making VirtualBox Fullscreen by Installing Guest Additions In Linux

If you've installed an operating system in VirtualBox before you've probably noticed the screen is really small even when you switch to Fullscreen mode.  It's so small that you can't even see the fonts for the icons if you have a desktop GUI installed.  To fix this problem VirtualBox provides us with the Guest Additions tool.  Which enables the virtual machine to be viewed at fullscreen.

To enable full screen on a Linux operating system.  Perform the following actions, this should work on all Linux distribution that VirtualBox supports.

1.  Start the virtual machine that you want to make full screen

2.  Log into your GUI desktop

3.  Click on "Devices" and then select "Insert Guest Additions CD Image"

Note: If you get the message "Unable to insert the virtual optical disk C:", Most likely you've already mounted the "Guest Additons" ISO on your virtual machine, so you should be good to go.

4. Start a terminal session, by searching the word "terminal" on the search box (GNOME).  Then click on the "Terminal" icon

5.  In your terminal session type "mount", you will see that VBOXADDITIONSxxxx has been mounted in your virtual machine with the path /media/....

6.  Switch to the VBOXADDITIONSxxxx folder, by typing in "cd /media/techjunkie/VBOXADDITIONS_4.3.22_98236/", the folder "techjunkie" is my user's home directory so your folder name will be different, and the numbers at the end of the VBOXADDITIONS...  is the version number so your number might be different.

7.  type "ls", you will see the file "VBoxLinuxAdditions.run"

8.  Type "sudo ./VBoxLinuxAdditions.run" in the terminal window

You will be asked for the sudo password, so enter the password and then press "Enter"

9.  The installation will take place automatically

10. Restart your virtual machine with the command "sudo reboot now" or restart the virtual machine itself in VirtualBox,  I prefer the second method, just to make sure.