runlevel

For historical reasons, the usual desktop Linux environment, with a graphical login program that spawns Gnome or KDE, is called runlevel 5.

Another way to think of runlevel is that it's a way to define which processes may execute (processes that define the state of the system).

Think of a runlevel as the state of the system.

Note: To see the current runlevel of your system, use the command runlevel.

This file provides init information on runlevels and on which processes should be launched on each runlevel.

At the end of execution of runlevel initial scripts, Linux will allow you to log in.

Note: if the system appears simply too slow to be bearable, you can exit X-windows by entering runlevel 3.

You can test the run level by issuing the runlevel command at the command prompt of your instance.

After system initialization is complete, init moves on to runlevel initialization.

The S indicates that the service is started when that runlevel is entered, while the K entry indicates that it should be stopped.

A runlevel is a defined set of system services that are run together.

On Linux, sending signals to init can change the system runlevel and even initiate system shutdown.

The q argument, rather than indicating a runlevel, tells init to reload its configuration files.

Note that some distributions differ on the runlevel representations.

These runlevel numbers are on the whole "well-known, " in the sense that most of them have very clearly defined meanings.

After the initial runlevel is defined, the script rc with the argument 2 (the runlevel) is invoked to bring the system.

Runlevel 0 means halt or stop the system, so you would not want to start any services when the machine is "coming down. "

This script specifies a service that is to be started for the given runlevel.

If this happens, reboot into single-user mode (runlevel 1), undo the changes you made, and then reboot.

Sadly, there's not a specific runlevel for "runlevel 3, only without yum-updatesd" .

If you are in runlevel 3, try the command xinit to start a bare-bones X session.

rc. 4 Multiuser startup (runlevel 4), but in X11 with KDM, GDM, or XDM as the login manager.

Runlevel 1 -- "single-user mode" -- is a special runlevel that is generally only used when something goes wrong.

At runlevel 3, simply log in as root on the terminal.

To test your installation on Ubuntu V7. 10, enter runlevel 1 and start GDM as root, preferably with the -nodaemon option.

From runlevel 3, start a bare-bones X session on the third client node with xinit.

Runlevels 2 through 5 are multi-user states, and runlevel 6 indicates reboot.

This is the default runlevel in Slackware.

For example, runlevel 0 defines the system halt state, runlevel 1 is the single-user mode.

So if you want to look at or modify the init script for runlevel 4, you want the file

The easiest way to achieve this is by switching to the first runlevel and back by entering