How to Upgrade Ubuntu 12.04 LTS to Ubuntu 14.04 LTS

This article will help you to upgrade Ubuntu 12.04 LTS to Ubuntu 14.04 LTS. Read more about Ubuntu 14.04 LTS.

Note: Before starting release upgrade on Ubuntu, We recommend to take backup of impotent data to other remote system or backup drive. We do not grantees that below steps will work for you properly. The commands use in this article has been taken from here.

To download Ubuntu 12.04 Trusty Tahr ISO images, Visit to http://releases.ubuntu.com/trusty/

Step 1: Install Ubuntu Core Update Mamanger

Generally update-manager-core was installed on system by default, but in case you do not have it, You can install it using following commands.

$ sudo apt-get update
$ sudo apt-get install update-manager-core

Step 2: Check Current Version and Available Upgrade

To check your current running version use lsb_release command.

$ lsb_release -a

LSB Version:    core-2.0-ia32:core-2.0-noarch:core-3.0-ia32:core-3.0-noarch:.....
Distributor ID: Ubuntu
Description:    Ubuntu 12.04 LTS
Release:    12.04
Codename:   precise

Now check for new Ubuntu release available to update

$ sudo do-release-upgrade --check-dist-upgrade-only --devel-release

Checking for a new Ubuntu release
New release '14.04' available.
Run 'do-release-upgrade' to upgrade to it.

The above output showing that newer release 14.04 is available to upgrade

Step 3: Upgrade to Ubuntu 14.04 LTS

Lets execute following command to upgrade ubuntu release to Ubuntu 14.04 LTS (Trusty Tahr).

$ sudo do-release-upgrade --devel-release

The above command will take long time to execute depends on your system configuration and internet speed. This will also ask for confirmation to proceed. Using –devel-release will upgrade to development (Unstable) release