performance tuning

Jure Pečar pegasus at
Wed Jan 28 05:42:55 EST 2004

On Tue, 27 Jan 2004 19:38:41 -0600
"Joe Hrbek" <jhrbek at> wrote:

> As a side note, when I run my programs, it brings my dual xeon 2.4ghz
> processors to 80% utilization (2 gigs of ram and raid 0). :D  Not
> important to the problem I don't think, but there ya go anyway, just if
> you are curious.
> Any ideas?  Let me know if I left something out.
> Cyrus IMAP4 v2.1.16
> postfix 2.0.16
> mysql 4.x (allows 1000 concurrent connections)
> Thanks!

80% cpu utilization?!? What are you doing? :)

About the only thing that would cause such cpu utilisation in your setup are
unindexed mysql tables. Be sure to check there if everything is indexed

All kinds of mail load are mostly i/o hungry. So if you suspect some problem
with your setup, put your postfix mail queues and cyrus mailstore on
somekind of ramdisk (tmpfs or similiar) and benchmark small changes to the
setup there.

For example, our ~200k users cyrus server runs on dual p3 1.2ghz on 30 15k
rpm fc disks in raid10 and cpu loads hovers around 20% on average with a
couple of hundred active connections. I/o wait is keeping loadavg above 1
most of the time, with peaks over 5 every now and then.


Jure Pečar

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