# kernel refuses devices mdadm -E accepts - List: linux-raid - 6 messages, 3 authors - Page: https://ratatoskr.run/linux-raid/2015/01/6628811/t ## kernel refuses devices mdadm -E accepts - From: Wesley W. Terpstra \ - Date: 2015-01-19 23:01:14 - Message: https://ratatoskr.run/linux-raid/2015/01/6628811.md ```text I have a raid5 array for which every disk, when examined with "mdadm -E /dev/sd[abcd]4" shows a Version: 1.2 superblock with a valid checksum. However, when I try: mdadm -A /dev/md/backing /dev/sd[abcd]4 mdadm says: mdadm: failed to add /dev/sdc4 to /dev/md/backing: Invalid argument mdadm: failed to add /dev/sdb4 to /dev/md/backing: Invalid argument mdadm: failed to add /dev/sda4 to /dev/md/backing: Invalid argument mdadm: failed to add /dev/sdd4 to /dev/md/backing: Invalid argument mdadm: /dev/md/backing assembled from 0 drives - need all 4 to start it (use --run to insist) The kernel says: md: sdc4 does not have a valid v1.2 superblock, not importing! md: md_import_device returned -22 md: sdb4 does not have a valid v1.2 superblock, not importing! md: md_import_device returned -22 md: sda4 does not have a valid v1.2 superblock, not importing! md: md_import_device returned -22 md: sdd4 does not have a valid v1.2 superblock, not importing! md: md_import_device returned -22 I was in the middle of a reshape of this 4-disk raid5 when something rebooted the computer. The system seems otherwise fine, and I suspect someone in the house. What is the correct next step? Should I try --run ? I would obviously prefer not to lose the data on this array. I expect that the reshape was NOT complete, so just recreating the array will probably corrupt its contents. Kernel version 3.17.8 and mdadm version 3.3.2. Thanks for any help. If I lose this array, I am going to face a lot of grief... ``` ## Re: kernel refuses devices mdadm -E accepts - From: Roger Heflin \ - Date: 2015-01-19 23:52:49 - Message: https://ratatoskr.run/linux-raid/2015/01/6628812.md ```text cat /proc/mdstat if the device is in use mdadm -E will work but you cannot create a device because one already has it. On Mon, Jan 19, 2015 at 5:01 PM, Wesley W. Terpstra [ref] wrote: > I have a raid5 array for which every disk, when examined with "mdadm > -E /dev/sd[abcd]4" shows a Version: 1.2 superblock with a valid > checksum. > > However, when I try: > mdadm -A /dev/md/backing /dev/sd[abcd]4 > mdadm says: > mdadm: failed to add /dev/sdc4 to /dev/md/backing: Invalid argument > mdadm: failed to add /dev/sdb4 to /dev/md/backing: Invalid argument > mdadm: failed to add /dev/sda4 to /dev/md/backing: Invalid argument > mdadm: failed to add /dev/sdd4 to /dev/md/backing: Invalid argument > mdadm: /dev/md/backing assembled from 0 drives - need all 4 to start > it (use --run to insist) > The kernel says: > md: sdc4 does not have a valid v1.2 superblock, not importing! > md: md_import_device returned -22 > md: sdb4 does not have a valid v1.2 superblock, not importing! > md: md_import_device returned -22 > md: sda4 does not have a valid v1.2 superblock, not importing! > md: md_import_device returned -22 > md: sdd4 does not have a valid v1.2 superblock, not importing! > md: md_import_device returned -22 > > I was in the middle of a reshape of this 4-disk raid5 when something > rebooted the computer. The system seems otherwise fine, and I suspect > someone in the house. > > What is the correct next step? Should I try --run ? I would obviously > prefer not to lose the data on this array. I expect that the reshape > was NOT complete, so just recreating the array will probably corrupt > its contents. > > Kernel version 3.17.8 and mdadm version 3.3.2. > > Thanks for any help. If I lose this array, I am going to face a lot of grief... > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html ``` ## Re: kernel refuses devices mdadm -E accepts - From: Phil Turmel \ - Date: 2015-01-20 18:28:23 - Message: https://ratatoskr.run/linux-raid/2015/01/6628822.md ```text Hi Wesley, On 01/19/2015 06:01 PM, Wesley W. Terpstra wrote: > I was in the middle of a reshape of this 4-disk raid5 when something > rebooted the computer. The system seems otherwise fine, and I suspect > someone in the house. > > What is the correct next step? Should I try --run ? I would obviously > prefer not to lose the data on this array. I expect that the reshape > was NOT complete, so just recreating the array will probably corrupt > its contents. > > Kernel version 3.17.8 and mdadm version 3.3.2. There have been many bug fixes to mdadm since that kernel was retired. You should temporarily boot a current liveCD (my favorite is systemrescuecd) and do "mdadm -Afv /dev/mdX /dev/sdX ..." Show us the output of that if it doesn't work (it should resume your reshape). When it is done reshaping/recovering, consider upgrading your kernel. > Thanks for any help. If I lose this array, I am going to face a lot of grief... I shouldn't have to say this, but RAID is for availability, not for data security. You still need a backup system for any important data. Phil ``` ## Re: kernel refuses devices mdadm -E accepts - From: Phil Turmel \ - Date: 2015-01-20 18:32:10 - Message: https://ratatoskr.run/linux-raid/2015/01/6628823.md ```text Woops! On 01/20/2015 01:28 PM, Phil Turmel wrote: > Hi Wesley, > > On 01/19/2015 06:01 PM, Wesley W. Terpstra wrote: > >> I was in the middle of a reshape of this 4-disk raid5 when something >> rebooted the computer. The system seems otherwise fine, and I suspect >> someone in the house. >> >> What is the correct next step? Should I try --run ? I would obviously >> prefer not to lose the data on this array. I expect that the reshape >> was NOT complete, so just recreating the array will probably corrupt >> its contents. >> >> Kernel version 3.17.8 and mdadm version 3.3.2. > > There have been many bug fixes to mdadm since that kernel was retired. > You should temporarily boot a current liveCD (my favorite is > systemrescuecd) and do "mdadm -Afv /dev/mdX /dev/sdX ..." I misread that kernel version. It's relatively current. Hmmm. I'd still try a liveCD with 3.18.x or 3.19. > Show us the output of that if it doesn't work (it should resume your > reshape). This still holds. :-) Phil ``` ## Re: kernel refuses devices mdadm -E accepts - From: Wesley W. Terpstra \ - Date: 2015-01-20 18:32:50 - Message: https://ratatoskr.run/linux-raid/2015/01/6628824.md ```text On Tue, Jan 20, 2015 at 7:28 PM, Phil Turmel [ref] wrote: >> Kernel version 3.17.8 and mdadm version 3.3.2. > There have been many bug fixes to mdadm since that kernel was retired. Really? I will give that a shot. > Show us the output of that if it doesn't work (it should resume your > reshape). I will try that. It was totally stupid reshape, I was changing the "data-offset" to align it. Really unnecessary, and really slow, so I feel like an idiot for starting it. >> Thanks for any help. If I lose this array, I am going to face a lot of grief... > I shouldn't have to say this, but RAID is for availability, not for data > security. You still need a backup system for any important data. Sure. The really vital (and small) stuff I have backed up elsewhere, but the sheer volume of raw video my girlfriend records is not economically feasible to backup beyond raid+btrfs snapshots. ``` ## Re: kernel refuses devices mdadm -E accepts - From: Wesley W. Terpstra \ - Date: 2015-01-20 18:43:40 - Message: https://ratatoskr.run/linux-raid/2015/01/6628826.md ```text An email race condition. ;-) On Tue, Jan 20, 2015 at 7:32 PM, Phil Turmel [ref] wrote: > Woops! > I'd still try a liveCD with 3.18.x or 3.19. Right. I am considering ordering one of these new 8TB hard disks so I can raw copy the raid partitions before I try anything drastic. Unfortunately even 8TB won't fit 4x3TB of data. :-/ I am fairly certain my data is still good since all disks have a clean bill of health and other partitions on them worked with bonnie. So, I figure my biggest risk right now, is doing something else stupid. The system remains bootable as the uefi+boot+root filesystems were on RAID1 x4 arrays and not the data RAID5 array. I'm hesitant to take action until I find away to store the raw partitions, but installing 3.19 and booting that from my existing root partition sounds harmless enough. The system does not have a CD-ROM and has insufficient SATA connectors to attach one. I could try booting via a USB drive, though. ```