From owner-freebsd-security  Sat Feb  8 12:56:42 1997
Return-Path: <owner-security>
Received: (from root@localhost)
          by freefall.freebsd.org (8.8.5/8.8.5) id MAA28745
          for security-outgoing; Sat, 8 Feb 1997 12:56:42 -0800 (PST)
Received: from roundtable.cif.rochester.edu (sadmin@roundtable.cif.rochester.edu [128.151.220.14])
          by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id MAA28738;
          Sat, 8 Feb 1997 12:56:37 -0800 (PST)
Received: (from sadmin@localhost) by roundtable.cif.rochester.edu (8.8.5/8.8.3) id PAA21546; Sat, 8 Feb 1997 15:55:41 -0500 (EST)
From: Security Administrator <sadmin@roundtable.cif.rochester.edu>
Message-Id: <199702082055.PAA21546@roundtable.cif.rochester.edu>
Subject: Re: Problems? or denial of service attack?
To: rls@mail.id.net (Robert Shady)
Date: Sat, 8 Feb 1997 15:55:41 -0500 (EST)
Cc: walth@scanners.tec.mn.us, slaterm@excel.tnet.com.au, questions@freebsd.org,
        isp@freebsd.org, security@freebsd.org
In-Reply-To: <199702081656.LAA03084@server.id.net> from "Robert Shady" at Feb 8, 97 11:56:42 am
X-Mailer: ELM [version 2.4 PL25]
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: owner-security@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

2-8-97

> 
> > > It looks like you are out of Swap space...
> > 
> >   This machine is a web server and email server.  There was nobody logged 
> > in at these times.  I have 32 megs of ram and 43 megs of swap.  There was 
> > also about 20 pages of messages having to do with sendmail.  Here are a 
> > few of those attached below.
> > 
> >   I have never had any problems before, and now when I was getting these 
> > sendmail problems I was getting all these messages.  I do not think that 
> > it is just a swap problem..
> 
> I thought the first poster was being sarcastic (He probably was), because
> it's so obvious that your problem *IS* that your running out of memory.
> I don't build a machine with less than 128MB of swap, 43 is nothing, 
> especially for a machine that's acting as a web server/mail server...
> 

We've got a machine with 128 Megs of on-board RAM.  We STILL decided to 
install twice the amount of cache (256 megs) split between two disks 
in the SCSI chain.  Splitting up the cache between the two disks should,
in theory, speed up your performance.

The conventional wisdom is to have at least twice your memory as swap.  In 
SunOS, for instance, it was hard to even get a machine to work unless you had 
an equal amount of swap and memory, no matter how much RAM was shoved into the
box.  

JP
-- 
System Security Administrator
Computer Interest Floor
University of Rochester
Rochester, NY 14627
sadmin@roundtable.cif.rochester.edu