Thread: Raid 5 array acting strange - superblock is corrupt, and disk is maybe faulty

hey everyone, i've been hacking @ on , off couple days , in little on head.

set raid 5 3 disks few years ago , have had no problems until had power outage last week. rebooted , md0 wouldn't come online. didn't save error message, said superblock bad. did research , decided force assembly.

code:

mdadm --assemble -f /dev/md0 /dev/sdb1 /dev/sdc1 /dev/sdd1

now i'm not sure what's going on, after can't mount device:

code:

mount -t jfs /dev/md0 /media/atropos/ mount: wrong fs type, bad option, bad superblock on /dev/md0,        missing codepage or helper program, or other error        in cases useful info found in syslog - try        dmesg | tail  or so

fsck not encouraging:

code:

$ sudo fsck /dev/md0  fsck 1.41.4 (27-jan-2009) fsck.jfs version 1.1.12, 24-aug-2007 processing started: 5/2/2013 6.48.58 using default parameter: -p current device is:  /dev/md0 ujfs_rw_diskblocks: read 0 of 4096 bytes @ offset 32768 ujfs_rw_diskblocks: read 0 of 4096 bytes @ offset 61440 superblock corrupt , cannot repaired since both primary , secondary copies corrupt.

here other relevant info:

code:

$ cat /proc/mdstat personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid5 sdc1[1] sdb1[3](s) sdd1[4](f)       2930271744 blocks level 5, 128k chunk, algorithm 2 [3/1] [_u_]

sdd1 failing reason, right? if examine each drive independently have different ideas what's going on raid. sdb1 doesn't see sdd1 in array, sdc thinks we're in trouble, , sdd thinks great. meanwhile, there's no superblock on md0:

code:

$ sudo mdadm --examine /dev/sdb1 /dev/sdb1:           magic : a92b4efc         version : 00.90.00            uuid : da23b88a:4d0610cf:b45df8ba:2efcec8c (local host atropos)   creation time : sat sep 26 21:57:56 2009      raid level : raid5   used dev size : 1465135872 (1397.26 gib 1500.30 gb)      array size : 2930271744 (2794.52 gib 3000.60 gb)    raid devices : 3   total devices : 3 preferred minor : 0       update time : thu may  2 06:10:19 2013           state : clean  active devices : 1 working devices : 2  failed devices : 1   spare devices : 1        checksum : a747a350 - correct          events : 3448            layout : left-symmetric      chunk size : 128k         number   major   minor   raiddevice state     3       8       17        3      spare   /dev/sdb1      0     0       0        0        0      removed    1     1       8       33        1      active sync   /dev/sdc1    2     2       0        0        2      faulty removed    3     3       8       17        3      spare   /dev/sdb1   $ sudo mdadm --examine /dev/sdc1 /dev/sdc1:           magic : a92b4efc         version : 00.90.00            uuid : da23b88a:4d0610cf:b45df8ba:2efcec8c (local host atropos)   creation time : sat sep 26 21:57:56 2009      raid level : raid5   used dev size : 1465135872 (1397.26 gib 1500.30 gb)      array size : 2930271744 (2794.52 gib 3000.60 gb)    raid devices : 3   total devices : 3 preferred minor : 0       update time : thu may  2 06:10:19 2013           state : clean  active devices : 1 working devices : 2  failed devices : 1   spare devices : 1        checksum : a747a362 - correct          events : 3448            layout : left-symmetric      chunk size : 128k         number   major   minor   raiddevice state     1       8       33        1      active sync   /dev/sdc1      0     0       0        0        0      removed    1     1       8       33        1      active sync   /dev/sdc1    2     2       0        0        2      faulty removed    3     3       8       17        3      spare   /dev/sdb1  $ sudo mdadm --examine /dev/sdd1 /dev/sdd1:           magic : a92b4efc         version : 00.90.00            uuid : da23b88a:4d0610cf:b45df8ba:2efcec8c (local host atropos)   creation time : sat sep 26 21:57:56 2009      raid level : raid5   used dev size : 1465135872 (1397.26 gib 1500.30 gb)      array size : 2930271744 (2794.52 gib 3000.60 gb)    raid devices : 3   total devices : 3 preferred minor : 0       update time : wed may  1 21:27:27 2013           state : clean  active devices : 2 working devices : 3  failed devices : 0   spare devices : 1        checksum : a74728cd - correct          events : 3440            layout : left-symmetric      chunk size : 128k         number   major   minor   raiddevice state     2       8       49        2      active sync   /dev/sdd1      0     0       0        0        0      removed    1     1       8       33        1      active sync   /dev/sdc1    2     2       8       49        2      active sync   /dev/sdd1    3     3       8       17        3      spare   /dev/sdb1     $ sudo mdadm --examine /dev/md0 mdadm: no md superblock detected on /dev/md0.

help? thinking removing sdd array , shoving in, terrifies me

how if try like:

code:

sudo mdadm --assemble --verbose --force --run --metadata=0.90 /dev/md0 /dev/sd[bcd]1

see if can help.

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