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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4F28C433EF for ; Thu, 31 Mar 2022 21:34:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241886AbiCaVgJ (ORCPT ); Thu, 31 Mar 2022 17:36:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233986AbiCaVgI (ORCPT ); Thu, 31 Mar 2022 17:36:08 -0400 Received: from smtp.hosts.co.uk (smtp.hosts.co.uk [85.233.160.19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E0EEA50E3A for ; Thu, 31 Mar 2022 14:34:19 -0700 (PDT) Received: from host86-155-180-61.range86-155.btcentralplus.com ([86.155.180.61] helo=[192.168.1.218]) by smtp.hosts.co.uk with esmtpa (Exim) (envelope-from ) id 1na2Qr-0005uF-5x; Thu, 31 Mar 2022 22:34:18 +0100 Message-ID: <8c2148d0-fa97-d0ef-10cc-11f79d7da5e5@youngman.org.uk> Date: Thu, 31 Mar 2022 22:34:17 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: Trying to rescue a RAID-1 array Content-Language: en-GB To: bruce.korb+reply@gmail.com Cc: linux-raid@vger.kernel.org References: From: Wols Lists In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org On 31/03/2022 19:14, Bruce Korb wrote: > On Thu, Mar 31, 2022 at 10:06 AM Wols Lists wrote: >> >> On 31/03/2022 17:44, Bruce Korb wrote: >>> I moved the two disks from a cleanly shut down system that could not >>> reboot and could not >>> be upgraded to a new OS release. So, I put them in.a new box and did an install. >>> The installation recognized them as a RAID and decided that the >>> partitions needed a >>> new superblock of type RAID-0. >> >> That's worrying, did it really write a superblock? > > Yep. That worried me, too. I did the command to show the RAID status of the two > partitions and, sure enough, both partitions were now listed as RAID0. > >>> Since these data have never been >>> remounted since the >>> shutdown on the original machine, I am hoping I can change the RAID >>> type and mount it >>> so as to recover my. .ssh and .thunderbird (email) directories. The >>> bulk of the data are >>> backed up (assuming no issues with the full backup of my critical >>> data), but rebuilding >>> and redistributing the .ssh directory would be a particular nuisance. >>> >>> SO: what are my options? I can't find any advice on how to tell mdadm >>> that the RAID-0 partitions >>> really are RAID-1 partitions. Last gasp might be to "mdadm --create" >>> the RAID-1 again, but there's >>> a lot of advice out there saying that it really is the last gasp >>> before giving up. :) >>> >> >> https://raid.wiki.kernel.org/index.php/Asking_for_help > > Sorry about that. I have two systems: the one I'm typing on and the one > I am trying to bring up. At the moment, I'm in single user mode building > out a new /home file system. mdadm --create is 15% done after an hour :(. > It'll be mid/late afternoon before /home is rebuilt, mounted and I'll be > able to run display commands on the "old" RAID1 (or 0) partitions. > >> Especially lsdrv. That tells us a LOT about your system. > > Expect email in about 6 hours or so. :) But openSUSE doesn't know > about any "lsdrv" command. "cat /proc/mdstat" shows /dev/md1 (the > RAID device I'm fretting over) to be active, raid-0 using /dev/sdc1 and sde1. Well, the webpage does tell you where to download it from - it's not part of the official tools, and it's a personal thing that's damn useful. > >> What was the filesystem on your raid? Hopefully it's as simple as moving >> the "start of partition", breaking the raid completely, and you can just >> mount the filesystem. > > I *think* it was EXT4, but. it might be the XFS one. I think I let it default > and openSUSE appears to prefer the XFS file system for RAID devices. > Definitely one of those two. I built it close to a decade ago, so I'll be moving > the data to the new /home array. > >> What really worries me is how and why it both recognised it as a raid, >> then thought it needed to be converted to raid-0. That just sounds wrong >> on so many levels. Did you let it mess with your superblocks? I hope you >> said "don't touch those drives"? > > In retrospect, I ought to have left the drives unplugged until the install was > done. The installer saw that they were RAID so it RAID-ed them. Only it > seems to have decided on type 0 over type 1. I wasn't attentive because > I've upgraded Linux so many times and it was "just done correctly" without > having to give it a lot of thought. "If only" I'd thought to back up > email and ssh. > (1.5TB of photos are likely okay.) > > Thank you so much for your reply and potentially help :) > If it says the drive is active ... When you get and run lsdrv, see if it finds a filesystem on the raid-0 - I suspect it might! There's a bug, which should be well fixed, but it might have bitten you. It breaks raid arrays. But if the drive is active, it might well mount, and you will be running a degraded mirror. Mount it read-only, back it up, and then see whether you can force-assemble the two bits back together :-) But don't do anything if you have any trouble whatsoever mounting and backing up. Cheers, Wol