From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753419AbYKSMZb (ORCPT ); Wed, 19 Nov 2008 07:25:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752698AbYKSMZX (ORCPT ); Wed, 19 Nov 2008 07:25:23 -0500 Received: from dedihh.fuckner.net ([81.209.183.161]:60180 "EHLO dedihh.fuckner.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752658AbYKSMZW (ORCPT ); Wed, 19 Nov 2008 07:25:22 -0500 X-Greylist: delayed 502 seconds by postgrey-1.27 at vger.kernel.org; Wed, 19 Nov 2008 07:25:22 EST Message-ID: <492403B8.5090007@fuckner.net> Date: Wed, 19 Nov 2008 13:16:56 +0100 From: Michael Fuckner User-Agent: Thunderbird 2.0.0.17 (X11/20080929) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Performance issues with Areca 1680 SAS Controllers Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I am using an Areca 1680-SAS-Controller with 16 SAS-HDD (Seagate 1TB ST31000640SS). I set up a Raid6 with all 16 disks and formatted it with XFS. The Controller has 512MB RAM and a BBU. The OS is installed to another disk attached to the onboard AHCI controller. After doing some IO, the areca raidset is slower compared to the rate directly after boot. [root@storage ~]# dd if=/dev/sdb1 of=/dev/null bs=1M count=50k iflag=direct 51200+0 records in 51200+0 records out 53687091200 bytes (54 GB) copied, 59.6494 seconds, 900 MB/s [root@storage ~]# mount /dev/sdb1 /data [root@storage ~]# cd /data/ [root@storage data]# ./iozone -i 0 -i 1 -s 32g -r 16m -S 6144 -t 8 -+r -o >raid6_sync_t8.log [root@storage data]# cd [root@storage ~]# umount /data/ [root@storage ~]# dd if=/dev/sdb1 of=/dev/null bs=1M count=50k iflag=direct 51200+0 records in 51200+0 records out 53687091200 bytes (54 GB) copied, 76.4036 seconds, 703 MB/s I tested different Versions of Linux (Centos 5.2, OpenSUSE 11, Debian Lenny) and Vanilla kernels 2.6.22-2.6.27, all show this behaviour. Idea why the device slows down after IO- or better: how to keep the high rate? Is this reproducible foer Areca SATA Controllers (Type 11XX and 12XX) Regards, Michael!