Linux Runlevels, Init 0 1 2 3 4 5 6 in Linux

In Linux, There are multiple (8) runlevels. Here I will talk about them.


What Is A Run Level

At any time, Any Linux System is in one of eight possible runlevels, A runlevel is a software configuration which only a selected group of processes can run.
Processes spawned by init for each of these run levels are defined in /etc/inittab

You can run init commands in the terminal as a root user

Init levels

0 :  Shutdown (goes thru the /etc/rc0.d/* scripts then halts)

1 :  Single user mode or emergency mode means no network no multitasking is present in this mode only root has access in this runlevel

2 :  No network but multitasking support is present .

3 :  Network is present multitasking is present but without GU.

4 :  Undefined, can be defined by the user

5 :  Network is present multitasking and GUI is present with sound etc.

6 :  System restart.

s, S, m, M : Tells the init command to enter the maintenance mode. When the system enters maintenance mode from another run level, only the system console
is used as the terminal.

And that’s it, Use init 0 for shutdown from now on (That’s what I do)

AND as someone once said







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