List Of Runlevels In Linux

when your linux server starts, it enters one of servearl runlevels, each of which corresponds to a specicif set of running services, this is the list:


# Default runlevel. The runlevels used by RHS are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)

explanation
Runlevel 0 - shuts down the server
Runlevel 1 - configures the server to run in a single-user maintenance mode
Runlevel 6 - reboots your server

on most linux systems, running level 3 corresponds to a multiuser text-mode boot and runelve 5 add X to the mix (when you have a GUI login prompt) slackware uses 3 and 4 for these functions. by default, debian attempts to start X in all its runlevels, in any event, one or two runleves are unused by defaults. you can start and stop services controlled through SysV startup scripts either temporary by running the scripts manually or permanently by setting the appropriate links to have the server start or stop the services when it reboots

so where do you change th runlevels?

you can change the runlevels in the /etc/inittab file