Ubuntu has the root account disabled and encourages the use of sudo to run commands as root. If you are doing some work requiring root access, it can be tiresome to type sudo over and over. The normal way to get a root shell is the su command, which doesn’t work in Ubuntu.
This command is the equivalent of su for Ubuntu, it asks for your password and switches to the root user:
And don’t forget to type exit to switch back to your normal user when you are done.