Hi Phil, Thank you so much to have taken the time to write back to me. I already tried --assemble --force, indeed and, that did not work. I guess it can work if you have a single drive which is out of sync but in my case, it is a mix of a drive with a problematic superblock (dmesg = does not have a valid v1.2 superblock, not importing!) plus a drive which is out of sync (dmesg = kicking non-fresh sdx from array!). Here is the output of --assemble --force with double verbose : # mdadm -vv --assemble --force /dev/md127 /dev/sdf /dev/sdg /dev/sdh /dev/sdi mdadm: looking for devices for /dev/md127 mdadm: /dev/sdf is busy - skipping mdadm: /dev/sdh is busy - skipping mdadm: /dev/sdi is busy - skipping mdadm: Merging with already-assembled /dev/md/xyz mdadm: /dev/sdi is identified as a member of /dev/md/xyz, slot 2. mdadm: /dev/sdh is identified as a member of /dev/md/xyz, slot 3. mdadm: /dev/sdf is identified as a member of /dev/md/xyz, slot 1. mdadm: /dev/sdg is identified as a member of /dev/md/xyz, slot 0. mdadm: /dev/sdf is already in /dev/md/xyz as 1 mdadm: /dev/sdi is already in /dev/md/xyz as 2 mdadm: /dev/sdh is already in /dev/md/xyz as 3 mdadm: failed to add /dev/sdg to /dev/md/xyz: Invalid argument mdadm: failed to RUN_ARRAY /dev/md/xyz: Input/output error If i stop the array (which was autostarted) and retry, similar output : # mdadm -S /dev/md127 mdadm: stopped /dev/md127 # mdadm -vv --assemble --force /dev/md127 /dev/sdf /dev/sdg /dev/sdh /dev/sdi mdadm: looking for devices for /dev/md127 mdadm: /dev/sdf is identified as a member of /dev/md127, slot 1. mdadm: /dev/sdg is identified as a member of /dev/md127, slot 0. mdadm: /dev/sdh is identified as a member of /dev/md127, slot 3. mdadm: /dev/sdi is identified as a member of /dev/md127, slot 2. mdadm: added /dev/sdf to /dev/md127 as 1 mdadm: added /dev/sdi to /dev/md127 as 2 mdadm: added /dev/sdh to /dev/md127 as 3 (possibly out of date) mdadm: failed to add /dev/sdg to /dev/md127: Invalid argument mdadm: failed to RUN_ARRAY /dev/md127: Input/output error Here is the relevant dmesg output : [173174.307703] sdf: unknown partition table [173174.308374] sdg: unknown partition table [173174.308811] md: bind<sdf> [173174.309385] sdh: unknown partition table [173174.309552] md: bind<sdi> [173174.310411] sdi: unknown partition table [173174.310573] md: bind<sdh> [173174.311299] sdi: unknown partition table [173174.311449] md: invalid superblock checksum on sdg [173174.311450] md: sdg does not have a valid v1.2 superblock, not importing! [173174.311460] md: md_import_device returned -22 [173174.311482] md: kicking non-fresh sdh from array! [173174.311498] md: unbind<sdh> [173174.311909] sdh: unknown partition table [173174.338007] md: export_rdev(sdh) [173174.338651] md/raid:md127: device sdi operational as raid disk 2 [173174.338652] md/raid:md127: device sdf operational as raid disk 1 [173174.338868] md/raid:md127: allocated 0kB [173174.338880] md/raid:md127: not enough operational devices (2/4 failed) [173174.338886] RAID conf printout: [173174.338887] --- level:5 rd:4 wd:2 [173174.338887] disk 1, o:1, dev:sdf [173174.338888] disk 2, o:1, dev:sdi [173174.339013] md/raid:md127: failed to run raid set. [173174.339014] md: pers->run() failed ... Thanks again, Tony On Thu, 2014-11-13 at 17:56 -0500, Phil Turmel wrote: > On 11/12/2014 10:58 AM, DeadManMoving wrote: > > Hi list, > > > > I have a failed RAID 5 array, composed of 4 x 2TB drives without hot > > spare. On the fail array, it looks like there is one drive out of sync > > (the one with a lower Events counts) and another drive with a missing or > > corrupted superblock (dmesg is reporting "does not have a valid v1.2 > > superblock, not importing!" and i have a : Checksum : 5608a55a - > > expected 4108a55a). > > > > All drives seems good though, the problem was probably triggered by a a > > broken communication between the external eSATA expansion card and > > external drive enclosure (card, cable or backplane in the enclosure i > > guess...). > > > > I am now in the process of making exact copies of the drives with dd to > > other drives. > > > > I have an idea on how to try to get my data back but i would be happy if > > someone could help/validate with the steps i intent to follow to get > > there. > > --create is almost always a bad idea. > > Just use "mdadm -vv --assemble --force /dev/mdX /dev/sd[abcd]" > > One drive will be left behind (the bad superblock), but the stale one > will be revived and you'll be able to start. > > If that doesn't work, show the output of the above command. Do NOT do > an mdadm --create. > > Phil > > -- > 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 -- 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
