On a normal install of Ubuntu Linux Desktop, you can access administrative privileges by prefixing commands with sudo. However, if you need to take administrative actions to handle many important tasks, you would want to enter a shell as root.
When entering the command su – root, you will be prompted for a password. However, there is no default password set for root. To get around this, you will have to set your own password.
sudo passwd root
Then you will be prompted with 3 password entries:
[sudo] password for username: Enter new UNIX password: Retype new UNIX password:
When you enter the password 3 times, you will see:
passwd: password updated successfully
Then you can use su – root with your newly created password to enter a root shell.