> From: Josh Berkus <josh@agliodbs.com>
>To: Scott Marlowe <scott.marlowe@gmail.com>
>Cc: pgsql-performance@postgresql.org
>Sent: Thursday, 21 February 2013, 3:14
>Subject: Re: [PERFORM] High CPU usage / load average after upgrading to Ubuntu 12.04
>
>
>> Sounds to me like your IO system is stalling on fsyncs or something
>> like that. On machines with plenty of IO cranking up completion
>> target usuall smooths things out.
>
>It certainly seems like it does. However, I can't demonstrate the issue
>using any simpler tool than pgbench ... even running four test_fsyncs in
>parallel didn't show any issues, nor do standard FS testing tools.
>
I've missed a load of this thread and just scanned through what I can see, so apologies if I'm repeating anything.
If the suspicion is the IO system and you've tuned everything you can think of; is there anything interesting
in meminfo/iostat/vmstatbefore/during the stalls? If so can you cause anything similar via bonnie++ with the "-b"
option?
