date: 2007-02-19 21:31:24+00:00

The Linux Runlevel

categories: - RHCE

I'm pretty sure they don't provide the root password at the RHCE exam and ask you to deal with it :)

Runlevels : * 0 - Halt the system * 1 - Single-user mode * 2 - Multi-user mode (without NFS) * 3 - Multi-user mode * 4 - Unused * 5 - Multi-user mode, graphical login * 6 - Reboot the system

Switch runlevel while the system is running (example : switch to runlevel 5) : telinit 5

Boot in a different runlevel (say 5 again) :

LILO : boot using "linux 5"

Grub : Edit the kernel line by pressing "e" and add "5" to the end of that line. Press enter then "b" to boot with the new parameter.

Changing the default runlevel : Edit /etc/inittab and edit this line, replace 3 by desired runlevel id:3:initdefault:

**Resetting the root password : ** - Boot in runlevel 1 - passwd root

You're done.