Having a play with the Beta of Ubuntu Intrepid 8.10 Beta under Virtualbox (2.0.2 at the time of writing), I noticed that the installation of the Virtualbox Guest Additions don’t appear to work in the usual manner. You’d reboot after installing them and, well, nothing new happens – no VBox video and mouse driver in operation.

EDIT: 26th Oct 2008 – Virtualbox 2.0.4 now has added support for Ubuntu Intrepid. If you are using Virtualbox 2.0.4, you should not have to perform any of the actions in this HowTo.

EDIT2: 29th october 2008 – While Virtualbox 2.0.4 now happily installs the correct video driver support for Ubuntu Intrepid, I’ve noticed that it still fails to install the GA mouse support. To fix this, just copy & paste only the “Input Device” section from the guide below into your /etc/X11/xorg.conf file and restart X.

EDIT3: These instructions will also work for subsequent Betas or new releases of Ubuntu where the video driver works, but not the mouse driver until Virtualbox is updated to support that new release of Ubuntu (eg: this was tested in Ubuntu Jaunty successfully as well which suffers the same problem Intrepid did before Virtualbox provided official support for it).

Having a closer look at the issue, basically the new xorg.conf file is VERY sparse and is normally where the Virtualbox GA video driver would be specified, so to fix this I tried listing it manually by editing the xorg.conf as follows:

$ sudo gedit /etc/X11/xorg.conf

…then on lines 21 to 23, comment out the existing “Device” listing by placing a hash at the start of the line as follows:

#Section "Device"
#    Identifier    "Configured Video Device"
#EndSection

…then scroll right to the bottom of the file and add the following lines:

Section "InputDevice"
    Identifier   "Configured Mouse"
    Driver       "vboxmouse"
    Option       "CorePointer"
EndSection

Section "Device"
    Identifier    "Configured Video Device"
    Driver        "vboxvideo"
EndSection

Save your changes and then exit out of the text editor.

Now just reboot Intrepid and viola – you now have working Virtualbox video and mouse driver! Yay! Brown Ibex goodness for everyone.