How To Upgrade Ubuntu 11.10 (Oneiric Ocelot) To 12.04 LTS (Precise Pangolin) (Desktop & Server) - Page 2
First become root:
and install the latest updates:
Then install the package update-manager-core:
apt-get install update-manager-core
Open the file /etc/update-manager/release-upgrades...
... and make sure it has Prompt=normal in it:
to start the distribution upgrade.
Checking package manager
Continue running under SSH?
This session appears to be running under ssh. It is not recommended
If you continue, an additional ssh daemon will be started at port
Continue [yN] <-- y
Starting additional sshd
To make recovery in case of failure easier, an additional sshd will
To continue please press [ENTER] <-- ENTER
During the update, a few services might need a restart. If the update manager asks you which services should be restarted (it shows a list of services), just accept the default services by pressing ENTER.
At the end of the upgrade process, you should remove obsolete packages:
Remove obsolete packages?
The server needs to be rebooted to complete the upgrade:
System upgrade is complete.
After the reboot, your server is running Ubuntu 12.04. To be sure, take a look at /etc/issue:
root@server1:~# cat /etc/issue