From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Mon, 31 Dec 2007 12:55:02 -0800 (PST) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.168.28]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id lBVKsrHq001538 for ; Mon, 31 Dec 2007 12:54:55 -0800 Received: from pan.gwi.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id C58F7BD557D for ; Mon, 31 Dec 2007 12:55:04 -0800 (PST) Received: from pan.gwi.net (pan.gwi.net [207.5.128.165]) by cuda.sgi.com with ESMTP id 9P3enyayhKV7rXok for ; Mon, 31 Dec 2007 12:55:04 -0800 (PST) Subject: Re: raid 10 su, sw settings From: Brad Langhorst In-Reply-To: <20071231201712.GA3679@teal.hq.k1024.org> References: <1199059239.13944.65.camel@up> <1199126586.3437.10.camel@up> <20071231201712.GA3679@teal.hq.k1024.org> Content-Type: text/plain Date: Mon, 31 Dec 2007 15:55:01 -0500 Message-Id: <1199134501.3437.21.camel@up> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Iustin Pop Cc: xfs@oss.sgi.com On Mon, 2007-12-31 at 21:17 +0100, Iustin Pop wrote: > On Mon, Dec 31, 2007 at 02:07:27PM -0500, Justin Piszcz wrote: > > On Mon, 31 Dec 2007, Brad Langhorst wrote: > >> On Mon, 2007-12-31 at 12:04 -0500, Justin Piszcz wrote: > >> > >>>> > >>>> Typical blocks/sec from iostat during large file movements is about > >>>> 100M/s read and 80M/s write. > >>>> > >>> > >>> #1 What type of performance do you expect with a 4-disk raid10? > >> > >> Are you saying that i should not expect more? > >> I expect about 70% better performance, since I think a single disk > >> should be able to do 100M/s. Maybe this is unreasonable? > > A single disk may do 90MiB/s burst but not sustained for read or write, at > > least not cheap SATA disks and when you get toward the middle part of the > > disk the speed wil drop off significantly. 100MiB/s read and 80MiB/s write > > for RAID10 sounds about right to me. Maybe someone else on the list with a > > similar configuration can chime in with their benchmarks. > > I agree about the disk speed - 100MiB/s for SATA drives is a little bit > too much to expect. And certainly, *only* in purely single-reader or > single-writer sequential workloads. > > I have the same config - 4 drive hw raid10 on 9650. A recent zcav log > shows read speeds start at around 140MiB/s and decrease toward 75MiB/s. > Since this is zcav from the bonie++ package, it doesn't take into > account any filesystem or partitioning overhead. I guess I should re-adjust my expectations Any opinions on the partition layout? Did you go to special effort to layout your partitions on the stripe boundaries (actually i don't really understand this fully yet).