[imp] urgent problem with IMP (i guess)

[Shane Williams]

On Tue, 23 Nov 2010, matiss at jekabsons.lv wrote:

> Hallo!
> First of all i am using horde groupware webmail ed.
> Sometimes our webmail is reaaaallly slow. And it seems that this slowliness 
> is caused by... sql or php(?)
> There are only 20 clients that are using this webmail. But it looks like that 
> with more users online is more slow server. Mabey you can give me some 
> sugestion to look at?
>
> Server is:
> HP ProLiant ML310 G4
> Dual-Core Intel® Pentium® D Processor 945 (3.40 GHz, 800 MHz, 2 x 2MB L2)
> PC2-5300 DDR2 2GB
> Hot plug Serial ATA HDD 7200rpm

I would check into disk I/O as a possible bottleneck.  Mail servers
(especially if they support IMAP) can make a lot of reads and writes,
and this obviously increases with user load.

I've run a home mailserver for years, with only a few users, and over
that time I've updated the disks that mail is stored on to newer
faster technology (sometimes inside the same box, so all other factors
remaining the same) and it's made a noticeable difference in access
time to read and write mail files.  Even moving to 10K SCSI or SATA
drive would probably show improvement, or, depending on the size of
your mail spools, solid state drives might be an option.

There are some good tips at
http://wiki.list.org/pages/viewpage.action?pageId=4030582
(Mailman wiki page on performance, which mostly focuses on MTA issues)

-- 
Shane Williams
Senior Information Technology Manager
School of Information, University of Texas at Austin
broot at ischool.utexas.edu - 512-471-9471