Upgrade Ubuntu 14.04 to Ubuntu 16.04 – Server Upgrade

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

$ sudo reboot

$ sudo apt-get install update-manager-core

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

$ sudo do-release-upgrade -d

$ sudo reboot

$ sudo apt-get install mariadb-server mariadb-client libmariadbd-dev libmariadb18