Xref: utzoo comp.unix.ultrix:1173 comp.unix.questions:14868
Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cbmvax!grr
From: grr@cbmvax.UUCP (George Robbins)
Newsgroups: comp.unix.ultrix,comp.unix.questions
Subject: Re: ps gives error
Keywords: memory ps core error
Message-ID: <7267@cbmvax.UUCP>
Date: 12 Jul 89 08:02:32 GMT
References: <209@larry.sal.wisc.edu>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Organization: Commodore Technology, West Chester, PA
Lines: 40

In article <209@larry.sal.wisc.edu> cathy@larry.sal.wisc.edu (Cathy Accettura) writes:
> I am having problems tracking down a problem.  That
> we appear to have every afternoon.  When I try to do
> a ps I get not enough memory.  When I do a df I get
> not enough core.  I don't see anything in crontab that
> is causing the problem.  I can do a pstat but I don't 
> know what I am looking for.

Generic problems with ps and it's memory peeking friends are usually
caused by booting from a kernel other than 'vmunix', such as genvmunix
or a new kenel you've generated and not renamed.

Your description would seem to indicate other problems, however,
probably inadequate swap space.  'pstat -s' is the tool for examinging
this.  You want to look at the ratio of 'used' to 'free' - the other
numbers range from confusing to bogus (it's better in 3.0 than before).

You can be eating up swap space if you have users running memory hungry
applications like gnu-emacs or lisp, or if you have lots of not-so-big
stuff running.  Having logins enabled on 32 serial lines, 32 pseudo-ttys
and 32 lat pseudo terminals can chew up a surprizing amout of swap space.
You can look at the SZ field in a 'ps -aux' output to try to spot who
the big hawgs are.

If you need more swap space, you *need* more, otherwise all kinds of
'invisible' tasks like sendmail or uucp will be failing due to out
of memory problems and your life will become painful and confusing.

To add more swap space, you must first have somewhere to put it.
Hopefully, you have several disks and there are unused 'b' partitions
just waiting for such use.  You then need to config a kernel that
lists these partitions in "swap on" clauses in the config statment
in the config file and make entries for all *except* the first on
in fstab, so that the "swapon -a" command in your /etc/rc file will
activate the additiona area(s).

-- 
George Robbins - now working for,	uucp: {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)