Steven,
> We saw the same performance problems when this new hardware was running
> cent 6.3 with a 2.6.32-279.19.1.el6.x86_64 kernel and when it was matched
> to the OS/kernel of the old hardware which was cent 5.8 with
> a 2.6.18-308.11.1.el5 kernel.
Oh, now that's interesting. We've been seeing the same issue (IO stalls
on COMMIT) ond had attributed it to some bugs in the 3.2 and 3.4
kernels, partly because we don't have a credible "old server" to test
against. Now you have me wondering if there's not a hardware or driver
issue with a major HW manufacturer which just happens to be hitting
around now.
Can you detail your hardware stack so that we can compare notes?
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com