From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E120C433E1 for ; Tue, 30 Mar 2021 03:15:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AECA619A6 for ; Tue, 30 Mar 2021 03:15:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230239AbhC3DOk (ORCPT ); Mon, 29 Mar 2021 23:14:40 -0400 Received: from u17383850.onlinehome-server.com ([74.208.250.170]:54674 "EHLO u17383850.onlinehome-server.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229762AbhC3DNv (ORCPT ); Mon, 29 Mar 2021 23:13:51 -0400 Received: by u17383850.onlinehome-server.com (Postfix, from userid 5001) id A451A79C; Mon, 29 Mar 2021 23:13:48 -0400 (EDT) Date: Mon, 29 Mar 2021 23:13:48 -0400 From: David T-G To: Linux RAID list Subject: Re: why won't this RAID5 device start? Message-ID: <20210330031348.GE1415@justpickone.org> References: <20210328021451.GB1415@justpickone.org> <6060D8AA.9030504@youngman.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6060D8AA.9030504@youngman.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Wol, et al -- ...and then Wols Lists said... % % On 28/03/21 03:14, David T-G wrote: % > ... % > system is running. Soooooo ... Where do I start? % > % > diskfarm:~ # cat /proc/mdstat % > Personalities : [raid6] [raid5] [raid4] % > md0 : active raid5 sdc1[3] sdd1[4] sdb1[0] % > 11720265216 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/3] [U_UU] % % This looks wrong - is this supposed to be a four-drive array? U_UU % implies a missing drive ... as does [4/3] Yep :-( I sent a separate note about that one. % > % > md127 : inactive sdl2[0](S) sdj2[3](S) sdf2[1](S) % > 2196934199 blocks super 1.2 % > ... % > diskfarm:~ # mdadm --examine /dev/sd[fjl]2 | egrep '/dev|Name|Role|State|Checksum|Events|UUID' % > /dev/sdf2: ... % > Events : 720 % > Device Role : Active device 1 % > Array State : AAA ('A' == active, '.' == missing, 'R' == replacing) % > /dev/sdj2: ... % > Events : 177792 % > Device Role : Active device 2 % > Array State : A.A ('A' == active, '.' == missing, 'R' == replacing) % > /dev/sdl2: ... % > Events : 177794 % > Device Role : Active device 0 % > Array State : A.. ('A' == active, '.' == missing, 'R' == replacing) % > % > Slice f2 looks great, but slices j2 & l2 seem to be missing -- even though % > they are present. Worse, the Events counter on sdf2 is frighteningly % > small. Where did it go?!? So maybe I consider sdf2 failed and reassemble % > from the other two [only] and then put f2 back in? % % Yes I'm afraid so. I'd guess you've been running a failed raid-5 for % ages, and because something hiccuped when you shut it down, the two good % drives drifted apart, and now they won't start ... Arrrgh :-( I was afraid of that ... % > % > Definitely time to stop, take a deep breath, and ask for help :-) % > % Read up about overlays on the web site, use an overlay to force-assemble Ouch. I tried that with a hiccup a few years ago and never really got it down. This is gonna take some reading again ... % the two good drives, run fsck etc to check everything's good (you might % lose a bit of data, hopefully very little), then if everything looks % okay do it for real. Ie force-assemble the two good drives, then re-add It looks like I want mdadm --assemble --force /dev/md127 /dev/sd[jl]2 for that based on the Go Wrong page and Go Wrogn collection. Does that sound right? % the third. I'd just do a quick smartctl health check on all three drives % first, just to make sure nothing is obviously wrong with them - a That looks good, although perhaps quite simple: diskfarm:~ # for D in /dev/sd[fjl] ; do echo "### $D" ; smartctl --health $D ; done ### /dev/sdf smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM) Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED ### /dev/sdj smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM) Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED ### /dev/sdl smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM) Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED But --info is longer and still doesn't give THAT much info, so maybe this is fine :-) % problem could kill your array completely! Then add the third drive back % in (whether you use --add or --re-add probably won't make much difference). OK. % % Oh - and fix whatever is wrong with md0, too, before that dies on you! Yeah, about that ... Haven't seen any replies there yet :-/ % % Cheers, % Wol Thanks again & HANN :-D -- David T-G See http://justpickone.org/davidtg/email/ See http://justpickone.org/davidtg/tofu.txt