Bob Kinney wrote: > Our director has been complaining about the performance while accessing > his mail. As such, we've begun the process of evaluating our entire > mail infrastructure to find out where the possible bottlenecks might be. ... > Does anyone have any suggestions for existing tools that can benchmark > IMAP performance and work well with courier?
I don't have any suggestions on the benchmarking front, but I can offer a few pieces of very general advice: 1) Don't use RAID 5! Particularly in large sets, RAID5 performance is very poor. Use RAID 10 with fast disks. 2) Stick with ext3 if you're running Linux. 3) Mount the filesystem with the "noatime" option. You'll save a significant amount of disk writes. 4) Make sure you have enough memory for your users. Each IMAP connection takes up about a megabyte of memory. If you allow 5 connections per user, provide for 5MB per user. Add more for file caching. I recommend 10-15 MB of RAM per user, minimum (1.5GB of RAM per 100 users). 5) Enforce (as a matter of policy) message archiving. Maildirs that grow beyond 5k messages are going to start killing performance. My recommendation is to instruct users to create an Archive folder, with subfolders representing past years or quarters. If they want to organize better than that, that's fine, but enforce some minimum level of organization and archiving. Maildir isn't going to support indefinite mailbox growth. (Even if the filesystem works, folder synchronization ends up consuming a lot of bandwidth). ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ courier-users mailing list [email protected] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
