1. How to enable root account?
Enabling root account is not at all require, however you may enable using ‘sudo -i‘ command to enable root access, you need to supply your password.
$ sudo -i
2. How to change root password?
You can change root password with ‘sudo passwd root‘ command as shown below.
$ sudo passwd root
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
3. How to disable root access?
You can disable root access with following command.
$ sudo passwd -l root