Muhammad SaDaT Anwar wrote:
>
> Dear All!
> Greetings!!
> Just a quick question:
> What is the relation between number of users popping their e-mails and
> the disk I/O?
>
> Cheers!
> Sadi
Disk performance is probably the most common bottleneck on a pop server.
Using fast drives and/or striping across multiple controllers, or using
fast hardware RAID are good ideas. You should run your favorite
monitoring tool (sar etc...) to check disk activity during heavy load.
If the disks are often at 100% busy, then you have I/O problems.
The type of filesystem also affects performance on large spool
directories. Especially if you're using UFS, or ext2, ( non-journaled
type filesystems ) you should consider hashing the spool directories
into multiple spools. These spools could be spread across multiple
disks/controllers. UFS takes a performance hit searching for files in
large directories.
Running server mode will greatly cut down on I/O. Check the INSTALL file
for details before you decide to use server mode. You should also
consider using a seperate drive/controller for the poptemp files. This
helps spread out I/O.
Lots of ram also helps.
-Joel
