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Re: High Load Average

"Jordi S. Bunster" wrote:

> We JUST installed the server. I mean, there's nothing hand
> compiled, except for Amavis. But it doesn't eat that much CPU

amavis is VERY cpu intensive i run it on many systems. is there a lot
of mail going through the system? is there a lot of big attachments?
one of my mail servers didnt dip below load of 8 until i upgraded the
system's hardware. amavis is great..but if you got a lotta mail you
need more horsepower.

also if your using something like UW Imap that can be a cause for very
high load as well. i suggest switching to something else like CYRUS which
reduces load by a factor of 100-200 (it did for me anyways) im sure there
are other good IMAP servers like courier(sp?) but i haven't tried them.

same goes for POP3. if your using qpopper or ipop3d those can be causes
of high load as well(cyrus has a pop3 server as well, does not
cause high load)

if you have a lot of mail going through i suggest setting up a raid0
array(or raid 10) for /var/spool and have amavis scan mail off that
drive. get SCSI if you can for this.

sample mail server config:
Average KB/hour of mail: 873kB/H
Max KB/hour of mail: 9944.7kB/H
Average Mail/hour: 71
Max Mail/hour: 1081

Average System Load: 1.02
Max System Load: 4.09

(Statistics gathered from MRTG over the past ~6 weeks or so)

System config:
Dual P3-800Mhz
Dual 15k RPM Ultra160 SCSI drives raid1 /var/spool
single 15k RPM Ultra160 drive (no raid) /
256MB ram
256MB swap
Uptime: 74 days
Time spent idle: 87.0%
Linux 2.2.17+many patches (openwall included)
Debian GNU/Linux 2.2r3
sendmail 8.9.3 + amavis
Squirrelmail (webmail front end)
Mcafee Antivirus 4.0.70

running amavis 0.2.1. hope this gives you an idea of what to expect
when using amavis as far as load goes.


ICQ: 75132336

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