Incative RAID5 (it should be active)

Incative RAID5 (it should be active)

[Jacob Madsen]

Hey

I only have 4 sata slots in my computer and i have a raid5 array of 
partitions on those 4 disks.

Today i needed a free sata slots, so i unplugged one of the disks and 
booted with knoppix. I then did some work, turned of the computer and 
plugged in the disk again.

I should say that i didnt use the array while using knoppix, so 
everything should be intact.

I then expected to be able to hotadd the missing partition and use the 
array as usual. But its inactive:

# mdadm --detail /dev/md8
mdadm: md device /dev/md8 does not appear to be active.

# cat /proc/mdstat
md8 : inactive sda10[1] sdd10[4] sdc10[3] sdb10[2]
      545791744 blocks

I then stopped the array:
# mdadm -S /dev/md8
mdadm: stopped /dev/md8

And tryed to assemble it:
# mdadm --verbose --assemble /dev/md8 /dev/sda10 /dev/sdb10 /dev/sdc10 
/dev/sdd10
mdadm: looking for devices for /dev/md8
mdadm: /dev/sda10 is identified as a member of /dev/md8, slot 1.
mdadm: /dev/sdb10 is identified as a member of /dev/md8, slot 2.
mdadm: /dev/sdc10 is identified as a member of /dev/md8, slot 3.
mdadm: /dev/sdd10 is identified as a member of /dev/md8, slot 4.
mdadm: no uptodate device for slot 0 of /dev/md8
mdadm: added /dev/sdb10 to /dev/md8 as 2
mdadm: added /dev/sdc10 to /dev/md8 as 3
mdadm: added /dev/sdd10 to /dev/md8 as 4
mdadm: added /dev/sda10 to /dev/md8 as 1
mdadm: /dev/md8 assembled from 2 drives and 1 spare - not enough to 
start the array.

The last line indicate something is wrong, but i have no idea what to 
do. (i still expect all the data to be intact)

Any good ideas will be appreciated alot!

/Jacob

Re: Incative RAID5 (it should be active)

[Jacob Madsen]

Hey again

here is some additional information:

# mdadm --examine /dev/sda10 /dev/sdb10 /dev/sdc10 /dev/sdd10
/dev/sda10:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fc549abf:0e1662f3:3b60b5c3:7a8e6fc7
  Creation Time : Tue Oct 19 20:27:43 2004
     Raid Level : raid5
    Device Size : 136447936 (130.13 GiB 139.72 GB)
     Array Size : 409343808 (390.38 GiB 419.17 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 8

    Update Time : Sat Aug 12 06:13:55 2006
          State : clean
 Active Devices : 2
Working Devices : 3
 Failed Devices : 1
  Spare Devices : 1
       Checksum : fc3ffb29 - correct
         Events : 0.35808971

         Layout : left-symmetric
     Chunk Size : 64K

      Number   Major   Minor   RaidDevice State
this     1       8       10        1      active sync   /dev/sda10

   0     0       0        0        0      removed
   1     1       8       10        1      active sync   /dev/sda10
   2     2       8       26        2      active sync   /dev/sdb10
   3     3       0        0        3      faulty removed
   4     4       8       58        4      spare   /dev/sdd10
/dev/sdb10:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fc549abf:0e1662f3:3b60b5c3:7a8e6fc7
  Creation Time : Tue Oct 19 20:27:43 2004
     Raid Level : raid5
    Device Size : 136447936 (130.13 GiB 139.72 GB)
     Array Size : 409343808 (390.38 GiB 419.17 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 8

    Update Time : Sat Aug 12 06:13:55 2006
          State : clean
 Active Devices : 2
Working Devices : 3
 Failed Devices : 1
  Spare Devices : 1
       Checksum : fc3ffb3b - correct
         Events : 0.35808971

         Layout : left-symmetric
     Chunk Size : 64K

      Number   Major   Minor   RaidDevice State
this     2       8       26        2      active sync   /dev/sdb10

   0     0       0        0        0      removed
   1     1       8       10        1      active sync   /dev/sda10
   2     2       8       26        2      active sync   /dev/sdb10
   3     3       0        0        3      faulty removed
   4     4       8       58        4      spare   /dev/sdd10
/dev/sdc10:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fc549abf:0e1662f3:3b60b5c3:7a8e6fc7
  Creation Time : Tue Oct 19 20:27:43 2004
     Raid Level : raid5
    Device Size : 136447936 (130.13 GiB 139.72 GB)
     Array Size : 409343808 (390.38 GiB 419.17 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 8

    Update Time : Sat Aug 12 00:11:10 2006
          State : clean
 Active Devices : 3
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 1
       Checksum : fc3fa60b - correct
         Events : 0.35808947

         Layout : left-symmetric
     Chunk Size : 64K

      Number   Major   Minor   RaidDevice State
this     3       8       42        3      active sync   /dev/sdc10

   0     0       0        0        0      removed
   1     1       8       10        1      active sync   /dev/sda10
   2     2       8       26        2      active sync   /dev/sdb10
   3     3       8       42        3      active sync   /dev/sdc10
   4     4       8       58        4      spare   /dev/sdd10
/dev/sdd10:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fc549abf:0e1662f3:3b60b5c3:7a8e6fc7
  Creation Time : Tue Oct 19 20:27:43 2004
     Raid Level : raid5
    Device Size : 136447936 (130.13 GiB 139.72 GB)
     Array Size : 409343808 (390.38 GiB 419.17 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 8

    Update Time : Sat Aug 12 06:13:55 2006
          State : clean
 Active Devices : 2
Working Devices : 3
 Failed Devices : 1
  Spare Devices : 1
       Checksum : fc3ffb59 - correct
         Events : 0.35808971

         Layout : left-symmetric
     Chunk Size : 64K

      Number   Major   Minor   RaidDevice State
this     4       8       58        4      spare   /dev/sdd10

   0     0       0        0        0      removed
   1     1       8       10        1      active sync   /dev/sda10
   2     2       8       26        2      active sync   /dev/sdb10
   3     3       0        0        3      faulty removed
   4     4       8       58        4      spare   /dev/sdd10