Virtualized MySQL Faster

I have an Xserve that’s still on 10.4. It runs a web app with a typical MySQL database backend. Both on metal.

This morning the DB got so slow that the app server started returning “timed out” error pages.

Ungood.

So I dumped the database, created a new Debian VMware instance and loaded up the data. I ssh port-forwarded metal’s 3306 to the new VM and restarted the apps.

Yesterday it took around seven seconds to vend a page. Now it’s back under half a second.

I wonder what I’m doing wrong that MySQL on OSX metal is an order of magnitude slower than MySQL on virtualized Linux.*

Could it be the default settings on Mac OS X Server 10.4 are that much worse than the defaults on Debian 5 Lenny?

Mac OS X’s file system is a lot slower than Linux’s, but I don’t think it could explain this much of a difference.

*You may assume I did the obvious things before migrating the DB from metal to VMware: restart the server, dump+reload the DB, etc.

mysql vmware sysadmin Jan 19 2010