SUMMARY: Setting Process Limits

From: vnarayan@ACC.HAVERFORD.EDU
Date: Tue Feb 09 1993 - 02:53:20 CST


My original message was:

>We are running SunOS 4.1.2 on our Sparc2. Recently we found that a single
>unprivileged user could bring the system to its knees by spawning lots of
>processes. Is it possible to set a limit on each user's processes so that
>this can't happen? Currently, the variable MAXUSERS is set to 8, NPROC is
>set to 138 and MAXUPRC is set to 135. I could give a lower value to
>MAXUPRC, but this would also limit the root's processes.

>So the question is: Is there is a way to limit the number of processes that
>a user can run, but exempt root from this restriction?

Hats off to the Sun Managers. You have proved to be more knowledable than
the Sun Employees themselves. Almost every one of you who responded to my
mail, pointed out that MAXUPRC is for *user* processes and that root will
not limited by it. In fact some of you even mentioned the number that
MAXUPRC was set to on your system and how root was running more processes
than that.

When I was first faced with the problem of setting process limits for
users, I called Sun's Tech support to see if there was a way of setting
process limits for an individual user, like disquotas. The person who took
my call said there was no way of doing it on an individual basis. He said
that setting the value of MAXUPRC was the only way of dealing with it and
added but 'remember this limit will also apply to the root, since root is a
user'. It did not make sense. But I said to myself, 'It does'nt mean it
cannot be true'. Hence I posted to the Sun Mangers to see what you all had
to say and I'm very glad I did.

Thanks to the following Sun managers who assisted me:

Chris Phillips <chris@cs.yorku.ca>
chip@eniac.seas.upenn.edu (Charles H. Buchholtz)
Nick Murray <nick@computing-science.aberdeen.ac.uk>
matthew@cs.adelaide.edu.au (Matthew Donaldson)
Cameron Humphries <cameron@cs.adelaide.edu.au>
mks!andy@watserv1.uwaterloo.ca (Andy Toy)
G.ROBERTSON@aberdeen.ac.uk
era@ncar.ucar.edu (Ed Arnold)
grs@claircom.com (Gregg Siegfried)
stern@sunne.East.Sun.COM (Hal Stern - NE Area Systems Engineer)
Christian Lawrence <cal@soac.bellcore.com>
trinkle@cs.purdue.edu (Daniel Trinkle)

PS: By the way I called Sun Tech and gave that guy a piece of my mind.

PSS: Sorry for the delay in posting the summary.



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