Subject: slow performace

From: Robert Hooper <[email-masked]>
Date: Mon, 04 Nov 2002 16:27:55 -0500

I just moved to a new server and am seeing very slow preformace,
and I cant figure out why. I'm using mbx and I bumped up the inetd
sessions, DNS looks fine and I dont think it uses IDENT. 

the old server was solaris 2.6 running IMAP4rev1 2000.277 the new one 
is 2.8 running  IMAP4rev1 2002.328
the new server was working great untill I moved a large number of users
over now its slow as a dog.
any help would be appriciated

-- 
Robert Hooper	         Systems Administrator, AT&T Labs Research
(973) 360-8737   C035    Systems and Networking Resources Partner
[email-masked]  Send Help requests to: [email-masked]
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From: Mark Crispin <[email-masked]>
Date: Mon, 4 Nov 2002 18:11:00 -0800 (PST)

Unfortunately, your message doesn't give enough information to go on.

How is the server slow?  Slow to connect?  Slow to authenticate?  Slow to open
the mailbox?

How much observed disk activity is there?  Is the disk thrashing?  What is the
load average?  How much swapping?

All these are things to look at.  I can't give you many more specifics, and I
am totally unfamiliar with Solaris so there may be other things to look at
that I'm not aware of.

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From: Robert Hooper <[email-masked]>
Date: Tue, 05 Nov 2002 09:13:24 -0500

sorry for being triss in my previous message but I was in panic mode;)

Access to large folders is where we first see problems, an open can take a
long time as can an append, as when saving a copy to Sent. Some users
see timeout errors. This problem seems to get worse over time.
from a systems perspective things look fine, memory is only about 50% used
1 of 2 Gigs no swaping, disk use is high 100% busy but rarely any waits,
and I can cat and ls files from the system easily.
CPU load is nonexistant. about 150-250 imapd processes
The system seems to work well right after a reboot but gets gradually 
worse over time.
Right now I'm thinking the problem is either the T3 RAID array with veritas
filesystem, or the Gigabit interface, but the old system was using
slower SCSI2 disks and 100baseT so it should be faster.
I would be interested in hearing from anyone with experiance tuning
a Solaris system for IMAP.

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From: Sebastian Hagedorn <[email-masked]>
Date: Tue, 05 Nov 2002 15:39:08 +0100

--On Tuesday, November 05, 2002 09:13:24 -0500 Robert Hooper 
<[email-masked]> wrote:

> Right now I'm thinking the problem is either the T3 RAID array with
> veritas filesystem, or the Gigabit interface, but the old system was using

Make sure that you have ufs logging activated. The last column in 
/etc/vfstab should have logging as a mount option. If you don't do that, 
Sun's ufs I/O performance is abysmal.

Greetings, Sebastian
--
Sebastian Hagedorn
Ehrenfeldgürtel 156
50823 Köln
http://www.spinfo.uni-koeln.de/~hgd/

Being just contaminates the void - Robyn Hitchcock