Runlevels

[Jonathan Hutchins]

On Saturday 11 September 2004 09:03 am, Charles Steinkuehler wrote:

> Usually, you can add 'single' or 'emergency' to boot into single-user
> recovery mode, or enter a number (ie: 3) to boot to a specific runlevel.

"Single" or "Emergency" are usually Runlevel 1, single-user repair mode.  
Level 3 is usually full-network services, everything except GUI; GUI mode is 
usually 5.  Level 6 is reboot.

Runlevel 2 is less commonly standardized, it's usually multi-user without 
networking, but is often undefined, and sometimes the equivalent of level 3 
(on some systems it's equivalent to 3 and is the default).

You should be able to tell your loader something like "linux 3" to specify a 
runlevel, where "linux" is one of the labels in the boot menu, not a specific 
command.  Most loaders also respond to "<label> single", some recognize "s" 
and/or "S".

Runlevels are part of the SysV init standard, and these days the distributions 
that don't actually use them emulate them (like gentoo).