So, we're beginning to see some not-so-good performance on our Zimbra server since installing 6.0.6. I'm not sure there's any relation to the version per se, we are migrating more and more accounts over to it, so that may very well be a reason.
I'm trying to do some performance-tuning reading .. our systems is a dual quad-core Xeon with 28GB of memory. It appears to me it's doing caching in the wrong places since the java process is consuming 8-12 GB depending on how you count. It'd be nicer to put some more memory to MySQL use, for example. Or message caching. As for message caching, I've seen these suggestions:
Except that the highest allowed value according to zmprov is 10000 .. (currently set to 2000).. say what?* To see current setting
zmprov gs `zmhostname` zimbraMessageCacheSize
* To modify setting
zmprov ms `zmhostname` zimbraMessageCacheSize 104857600
# can be set on global config or server
zmprov ms zimbraMessageCacheSize 104857600