How To Enable Root User (Super User) in Ubuntu

Question: how to able to do su – on Ubuntu. It says “su: Authentication failure”. How fix it, and possible to login to Ubuntu using root account directly?

Answer: Let us address these two questions one by one.

Warning: It is not recommended to enabled root. It is suggested that user should always try to perform all administrative tasks using ‘sudo’.

How to able to login using ‘su’ command

In Ubuntu, root account password is locked by default. So, when you want to do “su -”, you’ll get following Authentication failure error message.

 asifark@linuxpathfinder:~$ su -
 Password:
 su: Authentication failure

To enable super user account password

As following first of all set a password for root user.

 asifark@linuxpathfinder:~$ sudo passwd root
 [sudo] password for asifark:
 Enter new UNIX password:
 Retype new UNIX password:
 passwd: password updated successfully

You can login now as super user with su command with the new password.

 asifark@linuxpathfinder:~$ su -
 Password:
 root@linuxpathfinder:~#

How can we disable super user account password on Ubuntu

After that if you don’t want to use ‘su’ anymore, you can follow using one of the method to lock the root user password.

 asifark@linuxpathfinder:~$ sudo passwd -l root
 passwd: password expiry information changed.

( or )

 asifark@linuxpathfinder:~$ sudo usermod -p '!' root

How can we login directly using root account on Ubuntu?

First of all you will allow the root user to be logged in from the (X GUI) as explained below with the screenshot.

Go to System -> Administration -> Login window.

In the Security tab, click on “Allow local system administrator” near check box as you are seeing in the screenshot. Now you can login directly using root account after reboot the system.