Re: [Exim] Mail server load

On Wed, 27 Jun 2001, Scott Stavretis wrote:

> I am about to start using exim and need to build/find a server for it to
> run on. I would like some peoples opinion on what equipment they
> recommend I will need to run a mail server with around 30,000 users. I
> plan to run exim and qpopper on this server. Running Linux.

forget qpopper and the mbox format. opt for maildir and anything that
can handle that (courier works well here. and not just here *hint
hint*)

i'm serving a bit less than 40.000 users on an athlon 850 with 1G of
ram and regular ide disks (i'm not even sure about ata66...), the
memory is because this box is also a quite heavily used sql server (i
wouldn't have put more than 256M in it if itd been only mail), and the
peak loadavg (linux2.2) is around 0.4. when myuck^H^H^Hsql gets hit
big time, it goes up of course, but that unrelated.

most emails were ~200.000 a day total (sustained for a couple of
days), box didn't really take that as a challenge. i'd still have
sweet dreams if suddenly got hit by a rate of 12-15 incoming messages
a sec, sustained (that is, ~1.1-1.3 million a day)... i'd probably
change the disks to scsi ones and stripe 'em for io balancing, but
pretty much that's it.

if you're forseeing a lot if outgoing messages, you can consider
splitting the queue onto multiple disks or stripe arrays too -
remember, mail is io-challenged, anything else doesn't matter almost
at all (certain limits apply, of course).

--
[-]
"`rendes' `thread library' `unix' - ezeknek nincs kozos gyokuk" -- redax