From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759635AbXGLUVf (ORCPT ); Thu, 12 Jul 2007 16:21:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756814AbXGLUV2 (ORCPT ); Thu, 12 Jul 2007 16:21:28 -0400 Received: from omr8.networksolutionsemail.com ([205.178.146.58]:57081 "EHLO omr8.networksolutionsemail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756748AbXGLUV1 convert rfc822-to-8bit (ORCPT ); Thu, 12 Jul 2007 16:21:27 -0400 From: James Reply-To: LinuxKernel@jamesplace.net To: linux-kernel@vger.kernel.org Subject: Re: Problem recovering a failed RIAD5 array with 4-drives. Date: Thu, 12 Jul 2007 15:21:21 -0500 User-Agent: KMail/1.9.5 References: <200707120849.16068.LinuxKernel@jamesplace.net> <20070712164400.GD31195@csclub.uwaterloo.ca> In-Reply-To: <20070712164400.GD31195@csclub.uwaterloo.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline Message-Id: <200707121521.21407.LinuxKernel@jamesplace.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > On Thu, Jul 12, 2007 at 08:49:15AM -0500, James wrote: > > My apologies if this is not the correct forum. If there is a better place to > > post this please advise. > > > > > > Linux localhost.localdomain 2.6.17-1.2187_FC5 #1 Mon Sep 11 01:17:06 EDT 2006 > > i686 i686 i386 GNU/Linux > > > > (I was planning to upgrade to FC7 this weekend, but that is currently on hold > > because-) > > > > I've got a problem with a software RIAD5 using mdadm. > > Drive sdc failed causing sda to appear failed. Both drives where marked > > as 'spare'. > > > > What follows is a record of the steps I've taken and the results. I'm looking > > for some direction/advice to get the data back. > > > > > > I've tried a few cautions things to bring the array back up with the three > > good drives with no luck. > > > > The last thing attempted had some limited success. I was able to get all > > drives powered up. I checked the Event count on the three good drives and > > they were all equal. So I assumed it would be safe to do the following. I > > hope I was not wrong. I issued the following commands to try to bring the > > array into a usable state. > > > > > > > > > > []# > > mdadm --create --verbose /dev/md0 --assume-clean --level=raid5 --raid-devices=4 --spare-devices=0 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 > > Don't you want assemble rather than create if it already exists? > > How did two drives fail at the same time? Are you running PATA drives > with two drives on a single cable? That is a no no for raid. PATA > drive failures often take out the bus and you never want two drives in a > single raid to share an IDE bus. > > You probably want to try and assemble the non failed drives, and then > add in the new replacement drive afterwards, since after all it is NOT > clean. Hopefully the raid will accept back sda even though it appeared > failed. Then you can add the new sdc to resync the raid. > > -- > Len Sorensen > I should have included more information. When I attempted to --assemble the array I received the following: []# mdadm --assemble [--force --run] /dev/md0 /dev/sda1 /dev/sdb1 [/dev/sdc1] /dev/sdd1 mdadm: failed to RUN_ARRAY /dev/md0: Input/output error >>From what I read I assumed I could use the --assume-clean option with --create to bring the array back at least in some semblance of working order. I'd like to recover as much as possible from the RAID array. I actually have a nice new SATA configuration sitting here waiting to receive the data. This thing failed a day too early. I'm gnashing my teeth over this one. I'd truly appreciate any help/advice.