In this guide we will help you step by step upgrade Ubuntu 11.04 (Natty Narwhal) to Ubuntu 11.10 (Oneiric Ocelot) from the terminal. You may use the update manager (GUI) to do an upgrade, but you may get errors while using it. So, I opted for the method done via the terminal instead of the update manager.
1. Let's first update Ubuntu 11.04 using these two commands:
sudo apt-get update
sudo apt-get upgrade
2. Install now the update manager core package with this command:
sudo apt-get install update-manager-core
3. Edit now the update manager file with this command:
sudo gedit /etc/update-manager/release-upgrades
And check if this line is available:
4. Close the file and begin the upgrade process using this command:
5. During the upgrade process, you will be asked if you want to start the upgrade, type yes and press Enter:
6. wait now until the upgrade is complete and reboot your system.
7. Open now the terminal and check your current Ubuntu version with this command:
If the upgrade is successful, you will get this output:
~$ cat /etc/*-release