From mboxrd@z Thu Jan 1 00:00:00 1970 From: linbloke Subject: Re: persistent removed MD referrence on reboot Date: Wed, 01 Aug 2012 15:10:10 +1000 Message-ID: <5018BA32.8000801@fastmail.fm> References: <50173458.40505@websitemanagers.com.au> 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: Adam Goryachev , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 1/08/12 11:43 AM, Skip Coombe wrote: > Thanks for the quick response. > > I did "dd -if=/dev/zero -of=/dev/sdc" and modified the the partition to 83. > > Today I followed your advice to investigate initrd. I deleted all the > ARRAY specs from /etc/mdadm/mdadm.conf (they were > from the time of installing 12-4, including the md2 ARRAY), wrote the > new initrd, and rebooted. I think Adam led you to the right path. Your reference to 12-4 leads me to guess that you're running Ubuntu 12.04? For me on these systems, I would do the following: - zero superblocks: sudo mdadm --zero-superblock /dev/sdc1 running that commands multiple times until they return "No superblock found" or similar message. Once you get that response, there are no mdadm superblocks remaining. - update /etc/mdadm/mdadm.conf to remove references to old md arrays. - update initramfs: update-initramfs -u From there you should be able to reboot and find only those arrays specified in mdadm.conf (also arrays auto-built by the kernel from devices with partitions of type fd). If you're still not getting the expected outcome, pls send the output of "parted -l" and /etc/mdadm/mdadm.conf, uname -a, mdadm -V HTH j > The reference to md2 went away, but now I see > ====================== > $ cat /proc/mdstat > Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] > [raid4] [raid10] > md127 : inactive sdc[1](S) > 488385560 blocks super 1.2 > > unused devices: > ====================== > > I will repeat after "rm -rf /etc/mdadm" from the initrd dir tree. If > that does not work I will probably just reinstall 12-4. I hate to do > all the config again, but I've burned too many hours on this already. > There are no superblocks left so I hope to get a clean start. > > n.b. md127 seems to be the default array, but still sdc is identified. > There must be more info buried in the initrd. > > Thanks for the good advice, but I am still missing something. > > Skip > > On Mon, Jul 30, 2012 at 9:26 PM, Adam Goryachev > wrote: >> 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 > >