From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Tue, 12 Jun 2007 16:28:33 -0700 (PDT) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with SMTP id l5CNSOWt029708 for ; Tue, 12 Jun 2007 16:28:27 -0700 Date: Wed, 13 Jun 2007 09:28:17 +1000 From: David Chinner Subject: Re: sunit not working Message-ID: <20070612232817.GZ86004887@sgi.com> References: <1181608444.3758.73.camel@edge.yarra.acx> <902286657-1181653953-cardhu_decombobulator_blackberry.rim.net-1527539029-@bxe120.bisx.prod.on.blackberry> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <902286657-1181653953-cardhu_decombobulator_blackberry.rim.net-1527539029-@bxe120.bisx.prod.on.blackberry> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: salmr0@bp.com Cc: nscott@aconex.com, "Salmon, Rene" , xfs@oss.sgi.com On Tue, Jun 12, 2007 at 01:12:15PM +0000, salmr0@bp.com wrote: > > Thanks that helps. Now that I know I have the right sunit and swidth I have > a performace related question. > > If I do a dd on the raw device or to the lun directy I get speeds of around > 190-200 MBytes/sec. > > As soon as I add xfs on top of the lun my speeds go to around 150 > MBytes/sec. This is for a single stream write using various block sizes on a > 2 Gbit/sec fiber channel card. That's for buffered I/O, right? That sounds about right - if you do two writes, it should increase a little further. Also, direct I/O should be able to get you to >90% of the raw device capability.... Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group