X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 4869C9FA2A7 for ; Sun, 16 Jul 2006 20:12:01 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 83101-08 for ; Sun, 16 Jul 2006 23:11:56 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from cassarossa.samfundet.no (cassarossa.samfundet.no [129.241.93.19]) by postgresql.org (Postfix) with ESMTP id 187C19FA27F for ; Sun, 16 Jul 2006 20:11:56 -0300 (ADT) Received: from [2001:700:300:dc0f:216:3eff:fe40:5a47] (helo=trofast.sesse.net) by cassarossa.samfundet.no with esmtp (Exim 4.50) id 1G2FmC-0006TY-Ut for pgsql-performance@postgresql.org; Mon, 17 Jul 2006 01:11:53 +0200 Received: from sesse by trofast.sesse.net with local (Exim 3.36 #1 (Debian)) id 1G2FkT-0001FI-00 for ; Mon, 17 Jul 2006 01:10:05 +0200 Date: Mon, 17 Jul 2006 01:10:05 +0200 From: "Steinar H. Gunderson" To: pgsql-performance@postgresql.org Subject: Re: RAID stripe size question Message-ID: <20060716231005.GA4746@uio.no> Mail-Followup-To: pgsql-performance@postgresql.org References: <7F10D26ECFA1FB458B89C5B4B0D72C2B4E4BB1@sesrv12.wirelesscar.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <7F10D26ECFA1FB458B89C5B4B0D72C2B4E4BB1@sesrv12.wirelesscar.com> X-Operating-System: Linux 2.6.16trofastxen on a x86_64 X-Message-Flag: Outlook? --> http://www.mozilla.org/products/thunderbird/ User-Agent: Mutt/1.5.12-2006-07-14 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200607/158 X-Sequence-Number: 20018 On Mon, Jul 17, 2006 at 12:52:17AM +0200, Mikael Carneholm wrote: > Now to the interesting part: would it make sense to use different stripe > sizes on the separate disk arrays? In theory, a smaller stripe size > (8-32K) should increase sequential write throughput at the cost of > decreased positioning performance, which sounds good for WAL (assuming > WAL is never "searched" during normal operation). For large writes (ie. sequential write throughput), it doesn't really matter what the stripe size is; all the disks will have to both seek and write anyhow. /* Steinar */ -- Homepage: http://www.sesse.net/