Thank you Adam and linbloke. I ran "sudo mdadm --manage --stop /dev/md127" to clear out /proc/mdstat Then "sudo mdadm --zero-superblock /dev/sdc1" twice; no return info on the first one, but the second had a response similar to "No superblock found". Rebooted and the phantom raid device is gone. Skip On Wed, Aug 1, 2012 at 1:10 AM, linbloke <linbloke@xxxxxxxxxxx> wrote: > > 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:<none> >> ====================== >> >> 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 >> <adam@xxxxxxxxxxxxxxxxxxxxxx> 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:<none> >>>> ================================ >>>> >>>> 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 >> >> >> -- Skip Coombe skip.coombe@xxxxxxxxx 919.442.VLSI -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
