From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id oAU7nVW2064883 for ; Tue, 30 Nov 2010 01:49:31 -0600 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 0258B1B4DB0 for ; Mon, 29 Nov 2010 23:51:12 -0800 (PST) Received: from mail.internode.on.net (bld-mail17.adl2.internode.on.net [150.101.137.102]) by cuda.sgi.com with ESMTP id hFEF6VCWct2BT9JK for ; Mon, 29 Nov 2010 23:51:12 -0800 (PST) Date: Tue, 30 Nov 2010 18:51:09 +1100 From: Dave Chinner Subject: Re: XFS: performance Message-ID: <20101130075109.GN13830@dastard> References: <20101129001112.GA28672@dastard> <20101129015937.GB28672@dastard> <4CF33D0F.6080404@hardwarefreak.com> <20101130042913.GB3556@dastard> <4CF48299.2030204@hardwarefreak.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4CF48299.2030204@hardwarefreak.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Stan Hoeppner Cc: xfs@oss.sgi.com On Mon, Nov 29, 2010 at 10:50:33PM -0600, Stan Hoeppner wrote: > Dave Chinner put forth on 11/29/2010 10:29 PM: > > On Sun, Nov 28, 2010 at 11:41:35PM -0600, Stan Hoeppner wrote: > >> Yclept Nemo put forth on 11/28/2010 9:57 PM: > >>> You mention an eight-core machine (8c?). Since I operate a dual-core > >>> system, would it make sense to increase my AG count slightly, to five > >>> or six? > >> > >> Dave didn't mention the disk configuration of his "workstation". I'm > >> guessing he's got a local RAID setup with 8-16 drives. > > > > 2 SSDs in RAID0. > > From an IOPs and throughput perspective, very similar to my guess. > Curious, are those Intel, OCZ, or other SSDs? Which model, > specifically? Benchmark data? I ask as all the results I find on the > web for SSDs are from Windows 7 machines. :( I like to see some Linux > results. Cheap as it gets 120GB Sandforce 1200 drives. In RAID0, I'm getting about 450MB/s sequential write, a little more for read. I'm seeing up to 12-14k random 4k writes per drive through XFS. Other than that I didn't bother with any more benchmarks because it was clearly Fast Enough. > > And to point out the not-so-obvious, this is the _default layout_ > > that mkfs.xfs in the debian squeeze installer came up with. IOWs, > > mkfs.xfs did exactly what I wanted without me having to tweak > > _anything_. > > Forgive me for I've not looked at the code. How exactly does mkfs.xfs > determine the AG count? If you'd had a single 7.2k SATA drive instead > of 2 RAID0 SSDs, would it have still given you 16 AGs? If so, I'd say > that's a bug. No, it detected the RAID configuration. 16 AGs is the default for a RAID device, 4 AGs is used if RAID is not detected. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs