On 11/16/2009 8:00 AM, Nicolas GRENECHE wrote:
Hi all,
I plan to run a dovecot IMAPS and POPS service on our network. We handle about 3 000 mailboxes. I thought first buying a topnotch server (8 cores and 16 Go RAM) with equalogic iSCSI SAN SAS 15K for storage backend.
We run about 300 mailboxes, ~1 to 1.5 million inbound connections per month and about 1-1.5 million messages delivered to Dovecot per month on a low-end server. The O/S drive is 10k RPM SATA and the MailDir folders are stored on a 4-disk RAID-10 7200rpm SATA. It's a dual-core, ~2GHz, 64bit CentOS 5 server with only 4GB RAM. We also do anti-virus and spam filtering (SpamAssassin) scoring on that system along with using it for a few other tasks. The system chugs at times (during the daily backup window) but otherwise I'd say we're at about 25-30% load currently. Fortunately, providing basic mail service isn't that system intensive.
I think your sizing issue is going to be more about how many messages per month you're pushing through the system then sheer number of mailboxes. And maybe the overall size of the mail store. (Heck, our old mail server was a Solaris 200MHz x86 box with 256MB RAM and a pair of 80GB IDE drives setup before I took over administration of the mail system.)
Our current server was a test case that we put in about 18 months ago. Hopefully next year we can upgrade to better equipment (more cores, more memory, and more and faster spindles). And maybe some HA stuff like DRBD and Heartbeat.