Dynamically change screen resolution in Virtual Box for Linux host/guests.

If you install a new virtual Ubuntu machine (guest), in a Ubuntu system (host), by default the screen resolution is fixed to either 640x480; 800x600 or 1024x768.

You might want to change that to a system where the guest screen resolution is dynamically adjusted to the size of your window.

To do that you need to change some settings and make sure you have installed the guest additions correctly.


Procedure:

1. Turn off 3D Acceleration in the VM settings
   
   
2. Open Terminal screen and run these commands:
   
   

   sudo apt-get update  
   sudo apt-get upgrade  
   sudo apt-get install dkms  
   sudo apt-get install build-essential
   
   

3. From the Devices menu, select "install the Guest Additions (Host-D)".
   Normally the auto-run application will start to install the guest additions. If not, a new CDROM will appear on the desktop / file manager. Open the device and (Rightclick) start Autorun.
   
4. Restart the virtual machine
   
5. Now if you resize the window or choose Full Screen mode, it will resize the desktop screen resolution properly.