Received: with ECARTIS (v1.0.0; list xfs); Mon, 24 Sep 2007 13:40:25 -0700 (PDT) X-Spam-Checker-Version: SpamAssassin 3.2.0-pre1-r499012 (2007-01-23) on oss.sgi.com X-Spam-Level: X-Spam-Status: No, score=0.4 required=5.0 tests=AWL,BAYES_50 autolearn=ham version=3.2.0-pre1-r499012 Received: from stlx01.stz-softwaretechnik.com (stz-softwaretechnik.de [217.160.223.211]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with ESMTP id l8OKeFQ3013825 for ; Mon, 24 Sep 2007 13:40:20 -0700 Received: from rg by stlx01.stz-softwaretechnik.com with local (Exim 3.36 #1 (Debian)) id 1IZuiu-0001d7-00 for ; Mon, 24 Sep 2007 22:40:08 +0200 Date: Mon, 24 Sep 2007 22:39:58 +0200 From: Ralf Gross To: linux-xfs@oss.sgi.com Subject: Re: mkfs options for a 16x hw raid5 and xfs (mostly large files) Message-ID: <20070924203958.GA4082@p15145560.pureserver.info> References: <20070923093841.GH19983@p15145560.pureserver.info> <20070924173155.GI19983@p15145560.pureserver.info> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i X-Virus-Scanned: ClamAV version 0.90, clamav-milter version devel-120207 on oss.sgi.com X-Virus-Status: Clean X-archive-position: 13071 X-ecartis-version: Ecartis v1.0.0 Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com X-original-sender: Ralf-Lists@ralfgross.de Precedence: bulk X-list: xfs Justin Piszcz schrieb: >> A bit ot: will I waste space on the RAID device with a 256K chunk size >> and small files? Or does this only depend on the block size of the fs >> (4KB at the moment). > > That's a good question, I believe its only respective of the filesystem > size, but will wait for someone to confirm, nice benchmarks! > > I use a 1 MiB stripe myself as I found that to give the best performance. 256KB is the largest chunk size I can choose for a raid set. BTW: the HW-RAID is an Overland Ultamus 4800. The funny thing is, that performance (256KB chunks) is even better without adding any sw/su option to the mkfs command. mkfs.xfs /dev/sdd1 -f Sequential Reads File Blk Num Avg Maximum Lat% Lat% CPU Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff ----- ----- --- ------ ------ --------- ----------- -------- -------- ----- 20000 4096 1 208.33 23.81% 0.055 49.55 0.00000 0.00000 875 20000 4096 2 199.48 43.72% 0.116 376.85 0.00000 0.00000 456 Random Reads File Blk Num Avg Maximum Lat% Lat% CPU Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff ----- ----- --- ------ ------ --------- ----------- -------- -------- ----- 20000 4096 1 2.83 0.604% 4.131 38.81 0.00000 0.00000 469 20000 4096 2 4.53 1.700% 4.995 67.15 0.00000 0.00000 266 Sequential Writes File Blk Num Avg Maximum Lat% Lat% CPU Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff ----- ----- --- ------ ------ --------- ----------- -------- -------- ----- 20000 4096 1 188.15 42.98% 0.047 7547.93 0.00027 0.00000 438 20000 4096 2 167.76 76.89% 0.100 7521.34 0.00078 0.00000 218 Random Writes File Blk Num Avg Maximum Lat% Lat% CPU Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff ----- ----- --- ------ ------ --------- ----------- -------- -------- ----- 20000 4096 1 2.08 0.869% 0.016 0.13 0.00000 0.00000 239 20000 4096 2 1.80 1.501% 0.020 6.28 0.00000 0.00000 12 Ralf