Ubuntu 11.04 Natty Narwhal reaches its End-Of-Life
Ubuntu 11.04 Natty Narwhal was released on April 28th, 2011, consequently, due to Ubuntu’s 18 month security updates per non-LTS release (starting with Ubuntu 12.04 LTS, the 3 year per LTS period has been increased to 5 years long support for security and critical updates), benefits constantly added security fixes until October 28th, 2012.
Starting with October 28th, 2012, Natty Narwhal will reach its end of life and will not receive security and critical updates anymore, “forcing” the user to adopt newer supported versions of Ubuntu.
The user’s path is as simple as upgrading through Ubuntu 11.10 (“Ubuntu 11.10 continues to be actively supported with security updates and select high-impact bug fixes”) or install the at-the-moment current Ubuntu release, Precise Pangolin.
Step-by-step upgrade instructions (warnings and issuees included) are available on https://help.ubuntu.com/community/OneiricUpgrades.