Mirroring a failing HDD

[Shri Shrikumar <shri@kraya.co.uk>]

Hi All,

I tried posting this yesterday while not subscribed and didn't look like 
it got through - so trying again after subscribing. If it gets through 
twice - please accept my apologies.

I wonder if someone can help me with a problem that I am having.

There is a server(sarge) that I maintain that used to be mirrored and
all was well. However, the mirror was recently broken and when trying to
rebuild, I run into an interesting problem.

The array rebuilds to about 80% and then restarts. dmesg has the following:

RAID1 conf printout:
--- wd:1 rd:2
disk 0, wo:1, o:1, dev:sda3
disk 1, wo:0, o:1, dev:sdb3
..<6>md: syncing RAID array md1
md: minimum _guaranteed_ reconstruction speed: 1000 KB/sec/disc.
md: using maximum available idle IO bandwith (but not more than 200000
KB/sec) for reconstruction.
md: using 128k window, over a total of 155276160 blocks.
ata2: status=0x51 { DriveReady SeekComplete Error }
ata2: error=0x40 { UncorrectableError }
ata2: status=0x51 { DriveReady SeekComplete Error }
ata2: error=0x40 { UncorrectableError }
ata2: status=0x51 { DriveReady SeekComplete Error }
ata2: error=0x40 { UncorrectableError }
ata2: status=0x51 { DriveReady SeekComplete Error }
ata2: error=0x40 { UncorrectableError }
ata2: status=0x51 { DriveReady SeekComplete Error }
ata2: error=0x40 { UncorrectableError }
SCSI error : <1 0 0 0> return code = 0x8000002
sdb: Current: sense key: Medium Error
   Additional sense: Unrecovered read error - auto reallocate failed
end_request: I/O error, dev sdb, sector 268475518
ata2: status=0x51 { DriveReady SeekComplete Error }
ata2: error=0x40 { UncorrectableError }
SCSI error : <1 0 0 0> return code = 0x8000002
sdb: Current: sense key: Medium Error
   Additional sense: Unrecovered read error - auto reallocate failed
end_request: I/O error, dev sdb, sector 268475526
ata2: status=0x51 { DriveReady SeekComplete Error }
ata2: error=0x40 { UncorrectableError }

//..... removed few more of these lines

..<6>md: syncing RAID array md1
md: minimum _guaranteed_ reconstruction speed: 1000 KB/sec/disc.
md: using maximum available idle IO bandwith (but not more than 200000
KB/sec) for reconstruction.
md: using 128k window, over a total of 155276160 blocks.


Mirror information as follows:

$ sudo mdadm -D /dev/md1
/dev/md1:
       Version : 00.90.01
 Creation Time : Tue Nov  8 16:54:09 2005
    Raid Level : raid1
    Array Size : 155276160 (148.08 GiB 159.00 GB)
   Device Size : 155276160 (148.08 GiB 159.00 GB)
  Raid Devices : 2
 Total Devices : 2
Preferred Minor : 1
   Persistence : Superblock is persistent

   Update Time : Thu Nov  9 17:56:27 2006
         State : active, degraded, recovering
Active Devices : 1
Working Devices : 2
Failed Devices : 0
 Spare Devices : 1

Rebuild Status : 59% complete

          UUID : 526093bb:9a1af158:1faa9404:008c0621
        Events : 0.35102711

   Number   Major   Minor   RaidDevice State
      0       0        0        -      removed
      1       8       19        1      active sync   /dev/sdb3

      2       8        3        0      spare rebuilding   /dev/sda3


of the 159GB, only 60gb is allocated(using LVM) and I am guessing that
the failing part is within the unallocated section.

Any help in resolving this would be greatly appreciated. Please let me
know if you require any additional information.

Best Wishes,


Shri
PS: I am not subscribed to the list (too much traffic), so a cc: would
be greatly appreciated.

--
Shri Shrikumar
Technologist Extraordinaire
Kraya

t: 0845 644 4745
d: 0131 247 8021
f: 0131 478 7377
w: www.kraya.co.uk