Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934153AbdCWUJp (ORCPT ); Thu, 23 Mar 2017 16:09:45 -0400 Received: from box.mueller.org ([45.79.158.33]:43632 "EHLO mail.mueller.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754051AbdCWUJn (ORCPT ); Thu, 23 Mar 2017 16:09:43 -0400 Subject: Re: RAID array is gone, please help To: Lennart Sorensen References: <20170323173721.GA14188@csclub.uwaterloo.ca> <87d1da5c-a39b-fd41-62a7-640b0eea5501@mueller.org> <20170323192726.GM14186@csclub.uwaterloo.ca> <9dcb25dc-52f3-f831-6115-6a7feb07de1c@mueller.org> <20170323195903.GO14186@csclub.uwaterloo.ca> Cc: linux-kernel@vger.kernel.org From: Stephen Mueller Message-ID: Date: Thu, 23 Mar 2017 21:09:39 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170323195903.GO14186@csclub.uwaterloo.ca> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1530 Lines: 46 OK, I used gdisk to remove the GPT and MBR from each disk. mdadm --assemble still doesn't work... says it can't find the superblock. The mdadm --examine commands also say that no superblock is detected. I guess I'll go ahead with --create... On 3/23/2017 20:59, Lennart Sorensen wrote: > On Thu, Mar 23, 2017 at 08:38:08PM +0100, Stephen Mueller wrote: >> Apologies, I should have started this on linux-raid... >> >> >> stephen@fred> sudo gdisk -l /dev/sdc >> GPT fdisk (gdisk) version 1.0.1 >> >> Partition table scan: >> MBR: protective >> BSD: not present >> APM: not present >> GPT: present >> >> Found valid GPT with protective MBR; using GPT. >> Disk /dev/sdc: 7814037168 sectors, 3.6 TiB >> Logical sector size: 512 bytes >> Disk identifier (GUID): 60F1D54C-9D17-4688-BD6E-447F5E7408EB >> Partition table holds up to 128 entries >> First usable sector is 34, last usable sector is 7814037134 >> Partitions will be aligned on 2048-sector boundaries >> Total free space is 7814037101 sectors (3.6 TiB) >> >> Number Start (sector) End (sector) Size Code Name >> stephen@fred> >> >> The other disks are all similar. >> >> How do I remove the MBR/GPT tables? So you would do that, and then the >> mdadm --create? > > Well at least that seems to confirm that something restored the GPT from > the second copy at the end of the disk, wiping out the md superblock > at 4k. > > If you run gdisk /dev/sdc, it has a 'zap' option using the z key to > delete all traces of GPT. That ought to do what you want. >