> Hmmm, I've not seen this. For example, with people who are having trouble
> with checkpoint spikes on Linux, I've taken to recommending that they call
> sync() (via cron) every 5-10 seconds (thanks, Bruce, for suggestion!).
> Believe it or not, this does help smooth out the spikes and give better
> overall performance in a many-small-writes situation.
The reason is imho that the checkpoint otherwise also syncs all other
writes. These can be writes other backends had to do to replace a buffer.
Linux obviously lacks a mechanism to distribute the IO for cached writes
over time ala bgwriter (or does not do it when already faced with an IO bottleneck).
Andreas
