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 p6IJwuKq125006 for ; Mon, 18 Jul 2011 14:58:57 -0500 Received: from johnbokma.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 42D6F7C318 for ; Mon, 18 Jul 2011 12:58:55 -0700 (PDT) Received: from johnbokma.com (johnbokma.com [174.143.254.155]) by cuda.sgi.com with ESMTP id TWBSBQlYEYi6JNlE for ; Mon, 18 Jul 2011 12:58:55 -0700 (PDT) Received: from [192.168.1.100] (unknown [200.92.64.33]) by johnbokma.com (Postfix) with ESMTPSA id 87BB4120051 for ; Mon, 18 Jul 2011 19:58:55 +0000 (UTC) Message-ID: <4E24907F.6020903@johnbokma.com> Date: Mon, 18 Jul 2011 14:58:55 -0500 From: John Bokma MIME-Version: 1.0 Subject: 30 TB RAID6 + XFS slow write performance List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Dear list members, A customer of mine is currently struggling with the performance of a 30 = TB RAID6 which uses XFS as the filing system. I am somewhat sure it's = not XFS that's causing the performance issue but my expertise is not XFS = nor RAID; I just wrote the software that after moving to the larger RAID = (from a much smaller one, ~ 3TB, using ext3) suddenly seems to have a = huge drop in write performance. The software I wrote writes many small (50-150K) files in parallel (100+ = processes), thousands of times per hour. Writing a file of 50-150K now = and then seems to take between 30 and 90 seconds, and more rarely can = take over 200 seconds (several times an hour). When all processes are stopped and restarted again the 30-90 seconds = delay start happening when about 16-20+ processes are running. To me this sounds like something has been configured wrong. I already = recommended my customer to find someone who is capable of configuring = the RAID correctly; to me it sounds like a hardware/configuration issue. Any insights are very welcome. Hardware: card: MegaRAID SAS 9260-16i disks: 14x Barracuda=AE XT ST33000651AS 3TB (2 hot spares). RAID6 ~ 30TB Thanks for reading, John _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs