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 o747aeJA018065 for ; Wed, 4 Aug 2010 02:36:40 -0500 Received: from linta.de (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 3C439492C68 for ; Wed, 4 Aug 2010 00:36:56 -0700 (PDT) Received: from linta.de (isilmar-3.linta.de [188.40.101.200]) by cuda.sgi.com with ESMTP id iniYJxbYE2Jr3yHu for ; Wed, 04 Aug 2010 00:36:56 -0700 (PDT) Date: Wed, 4 Aug 2010 09:35:46 +0200 From: Dominik Brodowski Subject: How to track down abysmal performance ata - raid1 - crypto - vg/lv - xfs Message-ID: <20100804073546.GA7494@comet.dominikbrodowski.net> MIME-Version: 1.0 Content-Disposition: inline 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: linux-raid@vger.kernel.org, xfs@oss.sgi.com, linux-kernel@vger.kernel.org Hey, on a production system I run kernel 2.6.35 and XFS (rw,relatime,nobarrier) on a lvdevice of a vgroup consisting of five dm-crypt devices (cryptsetup -c aes-lrw-benbi -s 384 create) , each of which runs on a md-raid1 device (mdadm --create --level=raid1 --raid-devices=2) on two 750 GB ATA devices. The read performance is abysmal. The ata devices can be ruled out, as hdparm resulted in acceptable performance: > Timing cached reads: 9444 MB in 2.00 seconds = 4733.59 MB/sec > Timing buffered disk reads: 298 MB in 3.02 seconds = 98.73 MB/sec How can I best track down the cause of the performance problem, a) without rebooting too often, and b) without breaking up the setup specified above (production system)? Any ideas? perf(1)? iostat(1)? Thanks & best, Dominik _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs