From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751267AbVH2SOM (ORCPT ); Mon, 29 Aug 2005 14:14:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751272AbVH2SOL (ORCPT ); Mon, 29 Aug 2005 14:14:11 -0400 Received: from cramus.icglink.com ([66.179.92.18]:43649 "EHLO mx03.icglink.com") by vger.kernel.org with ESMTP id S1751265AbVH2SOK (ORCPT ); Mon, 29 Aug 2005 14:14:10 -0400 Date: Mon, 29 Aug 2005 13:14:03 -0500 From: Phil Dier To: linux-kernel@vger.kernel.org Cc: Scott Holdren , ziggy , Jack Massari Subject: Slow I/O with megaraid and u160 scsi jbod Message-Id: <20050829131403.21138526.phil@icglink.com> Organization: ICGLink X-Mailer: Sylpheed version 2.0.0 (GTK+ 2.4.4; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, I've had luck with this patch[1] (it at least eliminated the oopses I was getting), but now I'm having a different sort of problem with my setup[2] (the 2.6.13 release exhibits this behaviour as well). I have 2 u160 scsi jbods connected to this machine[3]. One is connected to an Adaptec card, and the other is connected to the Fusion MPT card (megaraid). All of the disks connected to the Adaptec card work fine, but when doing I/O on disks 2 and 3 on the megaraid card, it stalls considerably. When trying to sync a RAID1 device using the 4 148GB disks, the sync speed never goes above 2KB/s. When they finally get synched, IO stalls constantly. Watching with iostat confirms this. I've formatted the disks in question with a single JFS partition and they still exhibit this behaviour when used by themselves. I have verified that this behaviour is not present up until at least 2.6.12.3. Let me know what info I can collect that would be helpful.. Thanks. [1] http://www.ussg.iu.edu/hypermail/linux/kernel/0508.1/1952.html [2] http://www.icglink.com/debug-2.6.13-rc6.html [3] Diagram: +---------+ | Adaptec | +---------+ | +-------+-------+-------+-------+-------+ | id: 0 | id: 1 | id: 2 | id: 3 | id: 4 | | 73GB | 73GB | 148GB | 148GB | 73GB | +-------+-------+-------+-------+-------+ +----------+ | megaraid | +----------+ | +-------+-------+-------+-------+-------+ | id: 0 | id: 1 | id: 2 | id: 3 | id: 4 | | 73GB | 73GB | 148GB | 148GB | 73GB | +-------+-------+-------+-------+-------+ -- Phil Dier (ICGLink.com -- 615 370-1530 x733) /* vim:set noai nocindent ts=8 sw=8: */