device entry missing after reboot...

[Stefan Drees <s_drees@arcor.de>]

Hello,
i'm using debian since many years. At the beginning of the year, i 
switched to debian squeze
and for 2 weeks i migrated my raid1 with 2x500GB (sdc&sdd) to raid1 with 
2x1500GB (sdc&sdd).

I replaced /dev/sdd with a 1500GB HDD and created a new Raid1 (1 device 
missing) and
copied all data from the 500GB HDD to the 1500GB HDD. After all, i 
replaced /dev/sdc 500GB with
an 1500GB HDD and added it to the Raid1. After resync, everything seems 
to be fine but after
every reboot, the raid1 ist degraded because /dev/sdd1 is missing.

cat /proc/mdstat
md10 : active (auto-read-only) raid1 sdc1[0]
      1465135936 blocks [2/1] [U_]


mdadm --detail /dev/md10
/dev/md10:
        Version : 0.90
  Creation Time : Sat Feb 19 14:31:00 2011
     Raid Level : raid1
     Array Size : 1465135936 (1397.26 GiB 1500.30 GB)
  Used Dev Size : 1465135936 (1397.26 GiB 1500.30 GB)
   Raid Devices : 2
  Total Devices : 1
Preferred Minor : 10
    Persistence : Superblock is persistent

    Update Time : Thu Mar 10 23:15:41 2011
          State : clean, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

           UUID : 1208e3eb:9b2ac43b:93d0152c:154fa719 (local to host lost)
         Events : 0.13248

    Number   Major   Minor   RaidDevice State
       0       8       33        0      active sync   /dev/sdc1
       1       0        0        1      removed


fdisk -l /dev/sdd shows me:
/dev/sdd1   *           1      182401  1465136001   fd  Linux raid 
autodetect

But ls -al /dev/sdd* shows me only:
brw-rw---- 1 root disk 8, 48 11. Mär 06:42 /dev/sdd

So /dev/sdd1 is missing and i only get it back, if i rewrite the 
partition table with fdisk.
~# fdisk /dev/sdd
Command (m for help): w
Calling ioctl() to re-read partition table.
Syncing disks.

~# ls -al /dev/sdd*
brw-rw---- 1 root disk 8, 48 11. Mär 07:18 /dev/sdd
brw-rw---- 1 root disk 8, 49 11. Mär 07:18 /dev/sdd1

So i can add the missing hdd, again:
mdadm --add /dev/md10 /dev/sdd1

cat /proc/mdstat
md10 : active raid1 sdd1[2] sdc1[0]
      1465135936 blocks [2/1] [U_]
      [>....................]  recovery =  0.1% (1782656/1465135936) 
finish=287.3min speed=84888K/sec

Seems to be ok, but after reboot, /dev/sdd1 is missing again.

I zeroed the bootsecter of /dev/sdd, searched for sdd,md10 entrys in 
/etc/* and found nothing, created a
new raid1 only with /dev/sdd1, after reboot missing and so on. I don't 
have a clue.

Hope someone can help me.

Best regards
Stefan D.