Can't add device to raid 1 array - no error message

[Larkin Lowrey <llowrey@nuclearwinter.com>]

I am trying to replace the two small drives in my raid1 mirror with two
larger drives. I failed and removed the first drive and am now trying to
add a new larger drive to take its place. The add command completes
without any obvious error but the new dive is not added to the array.
What am I missing?

A superblock is written on the new array partition but its role is
'spare' and it does not show up in /proc/mdstat.

Kernel 3.2.7-1.fc16.x86_64
mdadm - v3.2.3 - 23rd December 2011

It appears that mdadm does detect an error but doesn't say anything
about it:

# mdadm --manage /dev/md0 --add /dev/sdz2 ; echo $?
1

I do see the following in the logs:

[ 2913.075120] scsi_verify_blk_ioctl: 74 callbacks suppressed
[ 2913.080708] mdadm: sending ioctl 1261 to a partition!
...
[ 2913.137556] mdadm: sending ioctl 1261 to a partition!

# mdadm -D /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Tue Jan 10 20:28:20 2006
     Raid Level : raid1
     Array Size : 15634360 (14.91 GiB 16.01 GB)
  Used Dev Size : 15634360 (14.91 GiB 16.01 GB)
   Raid Devices : 2
  Total Devices : 1
    Persistence : Superblock is persistent

  Intent Bitmap : Internal

    Update Time : Sat Mar  3 12:43:41 2012
          State : active, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

           Name : ***.*****.***:0  (local to host ***.*****.***)
           UUID : b5d9fcd0:5baaaff8:492c3e4b:22636aac
         Events : 499

    Number   Major   Minor   RaidDevice State
       0       0        0        0      removed
       1       8      130        1      active sync   /dev/sdi2

# mdadm -E /dev/sdz2
/dev/sdz2:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x1
     Array UUID : b5d9fcd0:5baaaff8:492c3e4b:22636aac
           Name : ***.*****.***:0  (local to host ***.*****.***)
  Creation Time : Tue Jan 10 20:28:20 2006
     Raid Level : raid1
   Raid Devices : 2

 Avail Dev Size : 83884032 (40.00 GiB 42.95 GB)
     Array Size : 31268720 (14.91 GiB 16.01 GB)
  Used Dev Size : 31268720 (14.91 GiB 16.01 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
          State : clean
    Device UUID : 50670e17:d3e5fe82:e572e701:7460bcc4

Internal Bitmap : 8 sectors from superblock
    Update Time : Sat Mar  3 12:41:18 2012
       Checksum : 4bb687db - correct
         Events : 0


   Device Role : spare
   Array State : .A ('A' == active, '.' == missing)

]# cat /proc/mdstat
Personalities : [raid1] [raid6] [raid5] [raid4]
md2 : active raid5 sdv2[9] sdo2[1] sdx2[4] sdl2[5] sdw2[10] sdp2[2]
sdk2[6] sdm2[8] sdq2[3] sdn2[7] sdr2[0]
      6641912320 blocks level 5, 128k chunk, algorithm 2 [11/11]
[UUUUUUUUUUU]

md1 : active raid5 sdx1[6] sdb1[9] sdp1[7] sdl1[11] sdr1[4] sdg1[3]
sdk1[10] sdq1[8] sdh1[0] sdv1[13] sdm1[14] sdw1[12] sdn1[2] sdf1[1] sdo1[5]
      4375960064 blocks level 5, 64k chunk, algorithm 2 [15/15]
[UUUUUUUUUUUUUUU]

md0 : active raid1 sdi2[1]
      15634360 blocks super 1.2 [2/1] [_U]
      bitmap: 1/1 pages [4KB], 65536KB chunk

unused devices: <none>

--Larkin