UnixServerAdmin

Server Administration & Management

How to enable user authentication for single user mode

By default you will be automatically logged in to single user mode as root, this can be security risk so better to
enable a user login add the single user mode.

Note – Debian and therefore Ubuntu both require root password when booting into single user mode or recovery mode. RHEL and CentOS allows access from the console into single user mode without a password. This is handy when things get messed up preventing access to the auth subsystems. To accomplish the same behavior under Ubuntu, edit the /etc/inittab file and change the line

1. To edit this system file

# vim /etc/inittab

2. Go to a new line at the end of file then type

sum:S:wait:/sbin/sulogin

3. Save this file

4. Exit the file

February 4, 2012 Posted by | Tips & Tricks, Unix/Linux | , , , | Leave a comment