Re: RAID Configuration Sugestion

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and learn from the discussion.

On Tue, Aug 30, 2005 at 10:15:13 -0300,
  Alvaro Nunes Melo <al_nunes@atua.com.br> wrote:
> Hello Bruno,
>
> Bruno Wolff III wrote:
>
> >On Tue, Aug 30, 2005 at 09:37:17 -0300,
> > Alvaro Nunes Melo <al_nunes@atua.com.br> wrote:
> >
> >
> >>The server is a Dual Xeon 3.0 with 2 GB RAM and two SCSI disks. Our main
> >>doubt is what is the best configuration for the disks. We are thinking
> >>about use them in a RAID-0 array. Is this the best option? What do you
> >>suggest on partitioning? Separate partitions for the OS, data and pg_xlog?
> >
> Our main goal is performance speedup. Disk space might not be a problem.
> I've read a lot here about movig pg_xlog to different partitions, and
> we'll surely make tests to see what configuration might be better.

This isn't a very good mix of hardware for running postgres. Xeons have
some context switching issues for which you will probably see some
speed up in 8.1. (So if you aren't going into production for sevral
months you might want to be using 8.1beta.) Having only two disk drives
is also not a good idea.

With what you have you either want to use raid 0 and not worry too much
about how the disks are partitioned or use one disk for wal logging
and the other for other stuff. There are other people on the list who
can probably give you a better idea of which of these options is likely
to be better in your case. However, they may need to know more about
your raid controller. In particular how much battery backed memory does
it have and its model.