"Benjamin Krajmalnik" <kraj@servoyant.com> writes:
> The only thing which I see when I run iostat is load on the drives every
> so often. Mifd0 is the database, mifd1 is the pg_xlog.
Hmm. Maybe checkpoints or something else saturating your drives for a
little while? You might want to be more aggressive about smoothing out
checkpoints, cf
http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm
At the very least I'd enable checkpoint logging for awhile and see
if there seems to be any correlation to the response-time glitches.
regards, tom lane