From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Thu, 18 Oct 2007 15:24:14 -0700 (PDT) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.11.20060308/8.12.10/SuSE Linux 0.7) with SMTP id l9IMO4Hw005618 for ; Thu, 18 Oct 2007 15:24:08 -0700 Date: Fri, 19 Oct 2007 08:23:57 +1000 From: David Chinner Subject: Re: raw vs XFS sequential write and system load Message-ID: <20071018222357.GN995458@sgi.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Mario Kadastik Cc: xfs@oss.sgi.com On Thu, Oct 18, 2007 at 12:50:44PM +0200, Mario Kadastik wrote: > Hello, > > I have a slight problem. Namely we have 4 systems with each having 2x > 3ware 9550SX cards in them each with hardware RAID5. Everything is > running the latest FW etc. The systems have at least 3GB of memory > and at least 2 CPU-s (one has 4GB and 4 cpu-s). Before going any further, what kernel are you using and what's the output of xfs_info of the filesytsem you are testing? FWIW, high iowait = high load average. High iowait is generally an indicator of an overloaded disk subsystem. You tests to the raw device only used a single stream, so it's unlikely to show any of the issues you're complaining about when running tens of parallel streams.... Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group