Ubuntu Server 20.04 Initial setup
1. Set the root password and use the SU command
In the default Ubuntu configuration, the root user is disabled because no password is set.
By setting a password for the root user, the traditional [su] command can be used for transitions
$ sudo passwd root
[sudo] password for ← Current user's password
Enter new UNIX password: ← Enter the root user password to be set
Retype new UNIX password: ← Enter your password again
passwd: password updated successfully
Switch to root user
$ su -
Password:
2. Modernisation of the system