X-Original-To: pgsql-general-postgresql.org@localhost.postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id BC6B79F9F3D for ; Tue, 9 May 2006 12:17:58 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 75579-07 for ; Tue, 9 May 2006 12:17:46 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from wolff.to (wolff.to [66.93.197.194]) by postgresql.org (Postfix) with SMTP id C97E79F946D for ; Tue, 9 May 2006 12:17:45 -0300 (ADT) Received: (qmail 13784 invoked by uid 500); 9 May 2006 15:18:48 -0000 Date: Tue, 9 May 2006 10:18:48 -0500 From: Bruno Wolff III To: "Jean-Yves F. Barbier" <7ukwn@free.fr> Cc: Hannes Dorbath , pgsql-general@postgresql.org, pgsql-performance@postgresql.org Subject: Re: Arguments Pro/Contra Software Raid Message-ID: <20060509151848.GA11476@wolff.to> Mail-Followup-To: Bruno Wolff III , "Jean-Yves F. Barbier" <7ukwn@free.fr>, Hannes Dorbath , pgsql-general@postgresql.org, pgsql-performance@postgresql.org References: <44606A98.4090705@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <44606A98.4090705@free.fr> User-Agent: Mutt/1.4.2.1i X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200605/345 X-Sequence-Number: 95137 On Tue, May 09, 2006 at 12:10:32 +0200, "Jean-Yves F. Barbier" <7ukwn@free.fr> wrote: > Naa, you can find ATA &| SATA ctrlrs for about EUR30 ! But those are the ones that you would generally be better off not using. > Definitely NOT, however if your server doen't have a heavy load, the > software overload can't be noticed (essentially cache managing and > syncing) It is fairly common for database machines to be IO, rather than CPU, bound and so the CPU impact of software raid is low. > Some hardware ctrlrs are able to avoid the loss of a disk if you turn > to have some faulty sectors (by relocating internally them); software > RAID doesn't as sectors *must* be @ the same (linear) addresses. That is not true. Software raid works just fine on drives that have internally remapped sectors.