From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Wed, 04 Apr 2007 07:35:52 -0700 (PDT) Received: from mail3b1.westend.com (mail3b.westend.com [212.117.79.78]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with ESMTP id l34EZkfB008940 for ; Wed, 4 Apr 2007 07:35:47 -0700 Date: Wed, 4 Apr 2007 16:35:33 +0200 From: Thomas Kaehn Subject: Re: Strange delete performance using XFS Message-ID: <20070404143533.GF12481@mail3b.westend.com> References: <20070404130535.GE18320@mail3b.westend.com> <20070404134724.GF18320@mail3b.westend.com> <20070404142142.GG18320@mail3b.westend.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Justin Piszcz Cc: xfs@oss.sgi.com Hi Justin, On Wed, Apr 04, 2007 at 10:24:42AM -0400, Justin Piszcz wrote: > >On Wed, Apr 04, 2007 at 10:12:48AM -0400, Justin Piszcz wrote: > >>On Wed, 4 Apr 2007, Justin Piszcz wrote: > >>>On Wed, 4 Apr 2007, Thomas Kaehn wrote: > >>>$ time for i in `seq 1 100000`; do dd if=/dev/zero of=$i bs=1k count=20 > >>>>/dev/null 2>&1; done > >>> > My guess is mkfs.xfs cannot optimzie for your array like it can with a SW > RAID device because it cannot see what is undereath it. Have you tried > making a SW RAID? I also use optimized parameters for my SW RAID1/5 as > well FYI. I guess this might be the problem. I've already tried to alter the stripe unit to match the RAID stripe size: "-d su=64k,sw=2 -l su=64k". Maybe the 3ware controller can't deal with the kind of read and write patterns needed by XFS. But in this case other people should have realized similar problems. On a different system with a 3ware 9500S-4LP using 4 disks as RAID5 setup I get a better (but not really good) result for delete performance (I've taken only 50000 files in this case as the system's CPU is much slower): | # time for i in `seq 1 50000`; do dd if=/dev/zero of=$i | bs=1k count=20 >/dev/null 2>&1; done | | real 18m21.643s | user 0m55.727s | sys 3m12.140s | backup:/srv/x# cd .. | backup:/srv# rm -rf x | | # time rm -rf x | | real 5m7.845s | user 0m0.160s | sys 0m11.369s Ciao, Thomas -- Thomas Kähn WESTEND GmbH | Internet-Business-Provider Technik CISCO Systems Partner - Authorized Reseller Im Süsterfeld 6 Tel 0241/701333-18 tk@westend.com D-52072 Aachen Fax 0241/911879 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Die Gesellschaft ist eingetragen im Handelsregister Aachen unter HRB 7608 Geschäftsführer: Thomas Neugebauer, Thomas Heller, Michael Kolb