Unity is a shell interface for the GNOME desktop environment that is integrated by default in Ubuntu 11.04 (Natty Narwhal) and UBuntu 11.10 (Oneiric Ocelot). The Unity project was founded in 2010 with the aim of bringing a consistent and flexible user experience for users of desktops and netbooks alike.
Unity includes a Dash for accessing installed applications along with an application launcher that makes it easy and fast accessing and bookmarking your favorite applications like your web browser, media player, etc.
However, some users who install Ubuntu 11.10 using VirtualBox, they notice after starting up their system that the Unity interface (Unity 3D) is not enabled and the classic Gnome interface is enabled instead.
In this guide we will help you activate Unity 3D for Ubuntu 11.10 Oneiric Ocelot, the steps are also applicable for Ubuntu 11.04. The tutorial is done under VirtualBox 4.1.4 and a virtual machine running Ubuntu 11.10.
1. Enabling 3D Acceleration
Launch VirtualBox, make a right click on the virtual machine running Ubuntu 11.10 and click Settings:
In the window that appears, click Display, check on "Enable 3D Acceleration", then click OK:
2. Installing Guest Additions
Using VirtualBox, start the virtual machine for Ubuntu 11.10. Wait until your system fully loads, then click Devices > Install Guest Addidtions:
Submit your root password when prompted:
Guest additions will now be installed. At the end of the operation, press the Return key or Enter to close the terminal:
3. Activating The Guest Additions for Linux Module
Open the terminal (Ctrl+Alt+T) and run this command to bring up the Additional Drivers window:
Select now "Oracle VM VirtualBox Guest Additions for Linux Module" and click Activate:
Reboot now your system (virtual machine) and The Unity interface will now be enabled: