PostgreSQL user experience: FreeBSD (ZFS) vs OpenIndiana (ZFS) vs Linux (EXT4)

[Adam Vande More]

On Sat, Dec 17, 2011 at 7:26 AM, Martin Matuska <mm at freebsd.org> wrote:

> I would like to share some of our expreience with PostgreSQL on FreeBSD.
> It has been a while ago since we had to stop using FreeBSD for our
> customer's PostgreSQL servers.
>

I don't claim any expertise in this area so please take this with that in
mind.

A couple of things that might help.

Setting zfs set sync=disabled on fs where the WAL resides(all alone).  Of
course this would help ZFS regardless of OS.

http://www.postgresql.org/docs/8.4/static/wal-intro.html

I've also seen other reports of slow PostgreSQL on FreeBSD, and in that
scenario there were a large amount of gettimeofday(2) calls as the
bottleneck and such calls on FreeBSD are significantly slower.

http://postgresql.1045698.n5.nabble.com/Postgresql-9-0-2-explain-analyze-very-slow-10x-compared-to-actual-query-time-td3336664.html

If you have a faster timecounter, it might help to switch.

-- 
Adam Vande More