Re: 3 x PostgreSQL in cluster/redunant

On Tue, Nov 15, 2005 at 12:09:40AM +0100, Johnny Ljunggren wrote:
> Jim C. Nasby wrote:
> >On Mon, Nov 14, 2005 at 07:36:44PM +0100, Michelle Konzack wrote:
> >>I have three Sun Server where I have reserved on each Server a Raid-5
>
> >Keep in mind that databases and RAID5 generally don't mix very well.
>
> oh, how come?
> What is the ideal setup of a database server when it comes to storage?

RAID5 has horrible write performance, especialy for random writes (which
is what databases tend to do). If you're running essentially a read-only
database then raid5 is OK. Otherwise you'll be much better off with
RAID10. You also want to put the WAL on a seperate set of drives from
the main database (though again that doesn't buy much if your database
is read-only).
--
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461