Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759338AbYCZMgi (ORCPT ); Wed, 26 Mar 2008 08:36:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755939AbYCZMga (ORCPT ); Wed, 26 Mar 2008 08:36:30 -0400 Received: from smtp8-g19.free.fr ([212.27.42.65]:34071 "EHLO smtp8-g19.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753088AbYCZMga convert rfc822-to-8bit (ORCPT ); Wed, 26 Mar 2008 08:36:30 -0400 Date: Wed, 26 Mar 2008 13:36:32 +0100 From: Emmanuel Florac To: "Bart Van Assche" Cc: linux-kernel@vger.kernel.org Subject: Re: RAID-1 performance under 2.4 and 2.6 Message-ID: <20080326133632.640aa0d2@harpe.intellique.com> In-Reply-To: References: <20080325194306.4ac71ff2@galadriel.home> <20080326120713.24cb8093@harpe.intellique.com> Organization: Intellique X-Mailer: Claws Mail 3.0.2 (GTK+ 2.12.9; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2759 Lines: 78 Le Wed, 26 Mar 2008 12:15:57 +0100 "Bart Van Assche" ?crivait: > You are welcome to post the numbers you obtained with dd for direct > I/O on a RAID-1 setup for 2.4 versus 2.6 kernel. Here we go (tested on a slightly slower hardware : Athlon64 3000+, nVidia chipset) . Actually, direct IO result is identical. However, the significant number for the end user in this case is the NFS thruput. 2.4 kernel (2.4.32), async write -------------------------------- root@0[root]# ./dd if=/dev/zero of=/mnt/raid/testdd01 bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 13.407 seconds, 80.1 MB/s 2.4 kernel (2.4.32), async write thru NFS mount -------------------------------- emmanuel[/mnt/temp]$ dd if=/dev/zero of=./testdd01 bs=1M count=1024 1024+0 enregistrements lus 1024+0 enregistrements ?crits 1073741824 bytes (1,1 GB) copied, 15,5176 s, 69,2 MB/s 2.4 kernel (2.4.32), async read -------------------------------- root@0[root]# ./dd if=/mnt/raid/testdd01 of=/dev/null bs=1M 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 15.752 seconds, 68.2 MB/s 2.4 kernel (2.4.32), sync write -------------------------------- root@0[root]# ./dd if=/dev/zero of=/mnt/raid/testdd01 bs=1M count=1024 \ oflag=direct,dsync 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 21.7874 seconds, 49.3 MB/s 2.6 kernel (2.6.22.18), async write -------------------------------- root@0[root]# ./dd if=/dev/zero of=/mnt/raid/testdd02 bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 17.1347 seconds, 62.7 MB/s 2.6 kernel (2.6.22.18), async write thru NFS mount -------------------------------- emmanuel[/mnt/temp]$ dd if=/dev/zero of=./testdd02 bs=1M count=1024 1024+0 enregistrements lus 1024+0 enregistrements ?crits 1073741824 bytes (1,1 GB) copied, 21,3618 s, 50,3 MB/s 2.6 kernel (2.6.22.18), async read -------------------------------- root@0[root]# ./dd if=/mnt/raid/testdd02 of=/dev/null bs=1M 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 15.7599 seconds, 68.1 MB/s 2.6 kernel (2.6.22.18), sync write -------------------------------- root@0[root]# ./dd if=/dev/zero of=/mnt/raid/testdd02 bs=1M count=1024 \ oflag=direct,dsync 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 21.7011 seconds, 49.5 MB/s -- ---------------------------------------- Emmanuel Florac | Intellique ---------------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/