Subject: Re: run levels (was Re: The new rc.d stuff...)
To: NetBSD-current Discussion List <current-users@NetBSD.ORG>
From: Perry E. Metzger <email@example.com>
Date: 04/24/2000 11:50:58
firstname.lastname@example.org (Greg A. Woods) writes:
> > I've never seen run levels used for any good purpose in any System V
> > installation, and I've worked on some pretty huge installations. Never
> > having seen a function for a facility leads me to belive that facility
> > is not useful. Run levels have always been a solution looking for a
> > problem, and they add complexity without giving any benefit in
> > return. They were a bad idea, and I see no reason to further a bad
> > idea.
> Just because you haven't personally seen it or haven't had the
> imagination to devise a use for it doesn't mean it doesn't exist.
> Some production systems, particularly larger and truly general-purpose
> central servers, have several operating states. They may change states
> several times per day, or only once per week or whatever.
My largest current client is the biggest securities clearing firm in
the world. They have truly astoundingly big farms of Suns. They do
batch processing and other "stateful" stuff regularly. They don't use
run levels for anything. They just have batch scripts that quiesce
their databases and then do their runs and what have you. I don't
think they've ever even considered using runlevels for this -- it
didn't occur to them, its so out of common practice.
This is hardly the only client of this size I've dealt with. None of
the rest of them have ever used run levels for anything --
ever. Machines are either up, or single user for maintenance, or
I've never seen run levels used the way you mention it. Never. Period.
Zippo. I've never even heard of it anecdotally from anyone
else. Unless you can give me a concrete example of a place that
actually uses them, I am disinclined to belive in them.
Even if you can give me an example or two, it isn't very meaningful.
I'm sure *someone* out there is using them -- everything you put in a
system will be used by *someone* given enough users -- but given the
breadth of my experience I'm inclined to believe they're just odd, and
could do what they want to do with run levels in another way.
You can claim, of course, that I'm just imposing my tastes on the
world and that I'm not omniscient. That's true. However, NetBSD is
very much a meritocracy of taste. We don't add everything -- we add
things very much based on our sense of aesthetics and
quality. Therefore, subjective judgments are sometimes needed, and
I'd say in this case, the general consensus is that runlevels are lame.
Perry Metzger email@example.com
"Ask not what your country can force other people to do for you..."