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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 D2C17C433ED for ; Mon, 17 May 2021 13:19:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B18D6610E9 for ; Mon, 17 May 2021 13:19:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235777AbhEQNUZ (ORCPT ); Mon, 17 May 2021 09:20:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235733AbhEQNUZ (ORCPT ); Mon, 17 May 2021 09:20:25 -0400 Received: from rin.romanrm.net (rin.romanrm.net [IPv6:2001:bc8:2dd2:1000::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C4B8C061573 for ; Mon, 17 May 2021 06:19:09 -0700 (PDT) Received: from natsu (natsu2.home.romanrm.net [IPv6:fd39::e99e:8f1b:cfc9:ccb8]) by rin.romanrm.net (Postfix) with SMTP id 48D316D9; Mon, 17 May 2021 13:19:06 +0000 (UTC) Date: Mon, 17 May 2021 18:19:05 +0500 From: Roman Mamedov To: Roger Heflin Cc: Christopher Thomas , Linux RAID Subject: Re: My superblocks have gone missing, can't reassemble raid5 Message-ID: <20210517181905.6f976f1a@natsu> In-Reply-To: References: <20210517112844.388d2270@natsu> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org On Mon, 17 May 2021 05:36:42 -0500 Roger Heflin wrote: > When I look at my 1.2 block, the mdraid header appears to start at 4k, and > the gpt partition table starts at 0x0000 and ends before 4k. > > He may be able to simply delete the partition and have it work. Christopher wrote that he tried: chris@ursula:~$ sudo /sbin/mdadm --verbose --assemble /dev/md0 /dev/sdb /dev/sdc /dev/sdd mdadm: looking for devices for /dev/md0 mdadm: Cannot assemble mbr metadata on /dev/sdb mdadm: /dev/sdb has no superblock - assembly aborted I would have expected mdadm when passed entire devices (not partitions) to not even look if there are any partitions, and directly proceed to checking if there's a superblock at its supposed location. But maybe indeed, from the messages it looks like it bails before that, on seeing "mbr metadata", i.e. the enclosing MBR partition table of GPT. -- With respect, Roman