Unix System V-style implement conventionally 7 runlevels. This runlevel implementation vary across many Linux distribution. Usually runlevel 0, 1 and 6 are the same.

  • 0 - halt
  • 1 - single mode
  • 6 - reboot

Debian distribution has it runlevel 2-5 dedicated to full multi-user with graphical managers and console login whereas Redhat/Fedora has two separate runlevels for each mode. To check the runlevel of you system you can use runlevel command with no arguments:

$ runlevel

another way to check your runlevel is to use:

$ who -r

To see what services are starting during which runlevel you can use:

# chkconfig

The same command also allows you to turn off and on each service for any particular runlevel. For example to run apache2 on level 2 you will use command:

# chkconfig apache2 2

Free Linux eBooks

Do you have the right skills?

Our IT Skills Watch page reflects an up to date IT skills demand leaning towards the Linux and Unix environment. We have considered a number of skills and operating systems.

See the result...

Go to top