Performance tuning

[joho]

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:

* To see current setting
zmprov gs `zmhostname` zimbraMessageCacheSize
* To modify setting
zmprov ms `zmhostname` zimbraMessageCacheSize 104857600

and

# can be set on global config or server
zmprov ms zimbraMessageCacheSize 104857600

Except that the highest allowed value according to zmprov is 10000 .. (currently set to 2000).. say what?


-joho

[Krishopper]

The attribute definition is "Maximum number of JavaMail MimeMessage objects in the message cache.", so I think they may have changed it from size (bytes/KB/etc.) to a simple count of the number of items at one point. Not sure when, though.

[joho]

Hmm.. but that could mean "any amount of memory", depending on how big the messages are.. no?



-joho

[LMStone]

Try running the script here as the zimbra user: http://mysqltuner.pl/mysqltuner.pl and post the results.

We can analyze the results for you and make some tuning recommendations accordingly.

If your mail volumes are picking up, I'd also recommend using a RAM disk for the Amavis temp directory to relieve pressure on the hard disks.

Hope that helps,
Mark