>>>>> On Thu, 13 Sep 2001 16:13:37 +0300 (EEST),
>>>>> Leena Heino <[EMAIL PROTECTED]> (lh) writes:
lh> We have about 11000 users on our mailserver and the server seems to be
lh> running out of resources ie. it seems to slow down when a lot of users
lh> (ie. 500-1000 imapd process are running in the system) are simultaneously
lh> reading their mail.
We currently have aroud 23000 users on our system, and are seeing
about 1200-1300 simultaneous sessions during peak of the day. This
is on a Sun E250 with dual 400MHz processors and about 1GB of RAM
(we're now working on getting that raised to 2GB). Storage is on a
Sun A3500 controller and some trays. We created a bunch of RAID5
(hardware) LUNs and striped them together using Veritas Volume
Manager. This is then a Veritas Filesystem. This box does NOT run
the main MTA (Postfix), but instead receives incoming mail strictly
via LMTP on a private network to the MTA router. Obviously Postfix
is on that box for stuff like Sieve vacation responses, but the
important thing is that the main MTA queue (HIGH I/O) is on a
different box. This is with a Cyrus CVS snag since 2.0.16 and Cyrus
SASL CVS snag since 1.5.27 (beta?).
Overall this hasn't been doing too poorly, though we really need to
get more memory. In your case, try to work on the I/O as much as
possible. Some arrangement of hardware RAID would probably help.
You might also split stuff off into different disks, like have the
mail folders storage space on one set of drives and /var/imap on
another.
--
Amos
