Jim,
> What about benefits from putting WAL and pg_temp on seperate drives?
> Specifically, we have a box with 8 drives, 2 in a mirror with the OS and
> WAL and pg_temp; the rest in a raid10 with the database on it. Do you
> think it would have been better to make one big raid10? What if it was
> raid5? And what if it was only 6 drives total?
OSDL's finding was that even with a large RAID array, it still benefits you to
have WAL on a seperate disk resource ... substantially, like 10% total
performance. However, your setup doesn't get the full possible benefit,
since WAL is sharing the array with other resources.
--
--Josh
Josh Berkus
Aglio Database Solutions
San Francisco