1. Normally, the Linux operating system will not prompt a root password when it is booting into single user mode. In term of security enhancement, you can set the Linux operating system to prompt a root password before entering the single user mode session. At the terminal, open text editor (vi editor) /etc/inittab file and add the following line inside it!
# vi /etc/inittab su:S:wait:/sbin/sulogin wq!
2. After save the changes, reboot the system into single user mode and verify the is it required a root password.
