Following is guide to upgrade from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS.
Make sure you are running a screen session before continuing.
Update & upgrade all packages
apt-get update apt-get upgrade
Install update-manager-core package:
apt-get install update-manager-core
Upgrade distro itself
You are now ready to upgrade to Ubuntu 12.04 LTS.
Open the release-upgrades file for editing by entering the following command:
Verify that the following line is present in the file, and that Prompt is set to lts:
Start a screen session:
screen -S distro
Upgrade your Linode to Ubuntu 12.04 LTS by entering the following command:
Follow the on-screen instructions to complete the installation process.
When the upgrade process completes, verify that it’s running Ubuntu 12.04 LTS by entering the following command
You should see output that resembles the following:
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=12.04 DISTRIB_CODENAME=precise DISTRIB_DESCRIPTION="Ubuntu 12.04"