> 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.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com