To login as root on Ubuntu 16.04, open the terminal and type this command.
This will give you a root prompt. Then enter this command to unlock the root account.
[email protected]:~# passwd root Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully
This allows the user to set a password for the root user and unlock the account. A very useful tip to make full use of your machine.
Now it works.
[email protected]:~$ su Password: root@jason-desktop:/home/jason#