Upgrade Ubuntu 14.04 to Ubuntu 16.04 – Server Upgrade

$ sudo apt-get update && sudo apt-get dist-upgrade

Then reboot your system to finish installing updates.

$ sudo init 6

First, install the update-manager-core package using the command below that is if it is not yet installed on your server:

$ sudo apt-get install update-manager-core

After that, edit this file, /etc/update-manager/release-upgrades using your favorite editor and set Prompt=ltsas in the output below:

$ sudo vi /etc/update-manager/release-upgrades

Configure Ubuntu Upgrade Manager

Next, start the upgrade process as follows:

$ sudo do-release-upgrade -d

Ubuntu 14.04 Upgrade Process

Then, enter 'y' for yes and hit the [Enter] to start the upgrade process in the output below:


Ubuntu 14.04 Upgrading to Ubuntu 16.04

As the upgrade process goes on, you will have to restart certain services on your system as in the output below, hit yes and continue.


Configure Services During Ubuntu Upgrade

You will be prompted to remove obsolete packages and just enter 'y' and after the upgrade process is complete, restart your server using the command below:

$ sudo init 6  

Now your system has been upgraded to Ubuntu 16.04 (Xerial Xerus) LTS.