Re: Install Postgres on a SAN volume?

On Mon, 8 Sep 2008, William Garrison wrote:

> I notice that the link you provided says:
> "Per best practices, my postgres data directory, xlogs and WAL archives are
> on different filesystems (ZFS of course). "
>
> Why is this a best practice? Is there a reference for that?

Those all have different ways they are used, and it's not unusual for
people to mount each with slightly different parameters or otherwise tune
them for their respective role.

There's also some physical properties involved. You probably want the WAL
files on the fastest parts of the disk (drive speed varies considerably
from the inside to the outside tracks), while the WAL archives can go onto
the slowest filesystem without a problem. The easy way to do that is to
partition the volume--normally the first partition you make will be
fastest, while the logical end of the disk is the slowest part.

--
* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD