HowTo: Upgrade To a Newer Version of Ubuntu 14.04 LTS

Back up any important data on the Ubuntu server

Make a backup - it cannot be stressed enough how important it is to make a backup of your system before you do this. Most of the actions listed in this post are written with the assumption that they will be executed by the root user running the bash or any other modern shell. Type the following commands to see current version:
$ uname -mrs
$ lsb_release -a
Sample outputs:

Linux 3.2.0-51-generic x86_64
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 12.04.4 LTS
Release:	12.04
Codename:	precise

How do I upgrade to a newer version of Ubuntu, such as v14.04, from an older v13.10 on a server system?

Type the following command to update package list and instal the update-manager-core package if it is not already installed:
$ sudo apt-get update
$ sudo apt-get install update-manager-core
Next, type the following command to upgrade the Ubuntu server to the latest release such as LTS 14.04 from the command-line. This is the recommended command as the server has no graphic environment or if the server is to be upgraded over a remote connection using ssh client:
$ sudo do-release-upgrade
The do-release-upgrade will launch the upgrade tool. You need to follow the on-screen instructions.

Fixing and forcing upgrade

You may end up getting the following message on screen when you run sudo do-release-upgrade

Checking for a new Ubuntu release
No new release found

Warning: The following method will check if upgrading to the latest devel (also known as unstable) release is possible via -d option.

To force upgrade pass the -d option to sudo do-release-upgrade command:

 
sudo do-release-upgrade -d
 

A note about upgrading from Ubuntu 13.10 on a desktop system

First, you need to remove all 3rd party binary drivers such as NVIDIA or AMD graphics card driver. Once removed and rebooted the desktop, press Alt+F2 and type in update-manager into the command box:

update-manager

Update Manager should open up and tell you: New distribution release '14.04 LTS' is available. Just click Upgrade and follow the on-screen instructions to upgrade your desktop systems.

Please note that all LTS desktop users need to wait till the first release called Ubuntu LTS v14.04.1 will be released by Canonical LTD. If you do not want to wait till LTS v14.04.1, pass the -d option to the update-manager command as follows to upgrade Ubuntu 12.04 LTS to Ubuntu 14.04 LTS:

 
sudo update-manager  -d
 

Reboot the server/desktop

Finally, reboot the system:
$ sudo reboot
Verify, your new settings:
$ lsb_release -a
$ uname -mrs
$ tail -f /var/log/app/log/file
Finally, reinstall 3rd party binary drivers.