Re: [TCLUG:20740] Magic runlevels

[Callum Lerwick <lerwick@tcfreenet.org>]

> AFAIK, runlevels 0, 1, and 6 are always, without exception, shutdown, single-
> user, and reboot.  Are these numbers hardcoded into the kernel/init or would
> it be possible to set up a system so that, e.g., runlevels 0-6 are normal
> multi-user modes and reboot, shutdown, and single-user are runlevels 7, 8,
> and 9 (without making any changes to the source)?  Not that this would be a
> Good Idea - I'm sure it would break many things - but I'm curious as to
> whether it's possible.

Naw, its no buisness of the kernel. Its an init thing. If you wanted to
change runlevels around, I don't think init would have a problem with
it. But note that shutdown/reboot/halt are hardcoded to runlevels 0,1,6,
you ought to be able to recompile the source to change that...

Anyway, if you wanted to change it, it shouldn't be all that hard. You
could even rip sysvinit out and put in a whole different init system
that runs on some other system than runlevels...

And for more neat info about how a Linux system boots, go read your lilo
docs...