How To Upgrade Ubuntu 11.10 (Oneiric Ocelot) To 12.04 LTS (Precise Pangolin) (Desktop & Server)
The new Ubuntu 12.04 LTS (Precise Pangolin) has just been released.
Ubuntu 12.04 LTS is a long-term support release, which means it is
supported for five years. This guide shows how you can upgrade your
Ubuntu 11.10 desktop and server installations to Ubuntu 12.04 LTS.