...I want it, but I don't have it.
We've got performance problems with our Zimbra server at my site. The load average on the box bounces between 2 and 7 during work hours (graph attached), and top shows 40-70% CPU time is in IO Wait. Mail operations like moving/deleting messages have become very slow, especially for imap and web-client users. I can't run filesystem backups during the day for fear of driving the disk I/O even higher.
Here's our setup:
Edit: 1 Zimbra server, ZCS 4.5.10
Dual Core AMD Opteron Processor 280 (2.4Ghz)
CentOS release 4.5, i686 (with PAE kernel)
3Ware 9550SX-8LP RAID card, BBU, cache enabled
4 x 250GB SATA disks (WD2500YS), RAID 10 configuration
I'm inclined to overhaul the RAID array with a) more, and b) faster disks. But before I go throw my company's $$ at 10k SATA disks, not to mention my time setting up and migrating to a different RAID device, I'm curious if there are software settings I should be tuning instead.
What kinds of hardware are other people using for similar numbers of users? How have you dealt with scaling Zimbra?
We started using Zimbra about a year ago with 25 users and great performance. Now I've got unhappy users who want to switch to Google Apps, or worse, hosted Exchange. Egads!
Thanks for your advice,