From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Sean R. Funk" Subject: Re: MDADM RAID 6 Bad Superblock after reboot Date: Thu, 19 Oct 2017 14:11:40 +0000 Message-ID: References: <6a0f0e0b-6b03-8ec1-b02f-b17b0447aff8@gmail.com> <59E7AE4B.5000903@youngman.org.uk> <63c30fde-d2df-bb92-d6c9-d231a955b5ce@gmail.com> <59E88568.6060108@youngman.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <59E88568.6060108@youngman.org.uk> Sender: linux-raid-owner@vger.kernel.org To: Wols Lists , linux-raid@vger.kernel.org List-Id: linux-raid.ids On October 19, 2017 3:58:48 AM PDT, Wols Lists wrote: > >Okay=2E First thing I'd try is temporarily get rid of mdadm=2Econf=2E You >don't actually need it=2E Then do "mdadm --stop /dev/md0" followed by >"mdadm --assemble --scan"=2E > Ok, so doing the stop, then assemble scan gets me : /Dev/MD/0 assembled from 5 drives - not enough to start the array=2E No arrays found in config file or automatically=2E This was after moving the mdadm=2Econf temporarily=2E >If that doesn't work, then try assembling the array explicitly, ie >listing all the drives=2E I can't remember whether order is important - >so >long as you don't specify --force it'll either work or fail, it won't >do >any damage=2E Looks like it's failed=2E I ran: mdadm --assemble /dev/md0 /dev/[abcde]1 /dev/sd[fgh]=20 Due to having to use a cell phone to respond I didn't type everything out = here, but that's the idea=2E Running that, I got: No superblock find on sdf expected magic a92b4efc, got 00000000 No raid superblock on sdf Sdf has no superblock assembly aborted This is where I've been stuck=2E I read a post a couple nights ago about z= eroing the superblock on the drives that report no superblock, but it seems= they are already zeroed? My lack of experience here isn't helping=2E