From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Goryachev Subject: Re: persistent removed MD referrence on reboot Date: Tue, 31 Jul 2012 11:26:48 +1000 Message-ID: <50173458.40505@websitemanagers.com.au> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Skip Coombe Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 07/31/2012 11:02 AM, Skip Coombe wrote: > I have an md entry referring to a badly removed RAID1 device (by me) after > the associated device crashed (can't afford a replacement drive at this > time). > Despite attempts to remove the reference, after a reboot I see: > > ================================ > $ cat /proc/mdstat > Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] > [raid10] > md2 : inactive sdc[1](S) > 488385560 blocks super 1.2 > > unused devices: > ================================ > > I am trying to repurpose the good drive as a not-RAID device. I have done > sudo mdadm --zero-superblock /dev/sdc > and > sudo mdadm --zero-superblock --force /dev/sdc > and even low level formatted /dev/sdc What do you mean "low level formatted"? Have you done a dd if=/dev/zero of=/dev/sdc > ================================ > $ ls /etc/mdadm/mdadm.conf > ls: cannot access /etc/mdadm/mdadm.conf: No such file or directory > ================================ Did you update the initrd file? This file probably contains a copy of the mdadm.conf Also, did you modify the partition type, from fd to 83 I would suggest running the above dd command, which will erase ALL traces of anything, including any data on the drive (so back it up elsewhere first). Most likely, the md code looks at a couple of different places on the drive for the md information, so when you run the zero-superblock, it is only erasing one of the possible locations. See man mdadm, especially the --metadata section. Regards, Adam