Comment 2 for bug 1190295

I was expecting the RAID system to blow up so I saved the scroll-back of the terminal. This is the state of the disk subsystem and RAID info prior to rebooting. Of particular note, /dev/md0p1 is marked as Linux Raid Autodetect but it's supposed to be an LVM partition!

$ ssh root@newbox
Linux newbox 3.0.0-32-server #51~lucid1-Ubuntu SMP Fri Mar 22 17:53:04 UTC 2013 x86_64 GNU/Linux
Ubuntu 10.04.4 LTS

Welcome to the Ubuntu Server!
 * Documentation: http://www.ubuntu.com/server/doc

  System information as of Wed Jun 12 10:08:23 CDT 2013

  System load: 0.15 Processes: 171
  Usage of /home: 0.8% of 3.99GB Users logged in: 0
  Memory usage: 0% IP address for eth0: 10.140.136.41
  Swap usage: 0%

  Graph this data and manage this system at https://landscape.canonical.com/

18 packages can be updated.
11 updates are security updates.

New release 'precise' available.
Run 'do-release-upgrade' to upgrade to it.

Last login: Wed Jun 12 10:07:11 2013

# screen -x
[detached from 1306.tty1.newbox]

# fdisk -l

Disk /dev/sda: 60.0 GB, 60022480896 bytes
32 heads, 32 sectors/track, 114483 cylinders
Units = cylinders of 1024 * 512 = 524288 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000cb60c

   Device Boot Start End Blocks Id System
/dev/sda1 1 114484 58615640 fd Linux raid autodetect

Disk /dev/sdb: 60.0 GB, 60022480896 bytes
32 heads, 32 sectors/track, 114483 cylinders
Units = cylinders of 1024 * 512 = 524288 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000da964

   Device Boot Start End Blocks Id System
/dev/sdb1 1 114484 58615640 fd Linux raid autodetect

Disk /dev/sdc: 1000.0 GB, 999989182464 bytes
255 heads, 63 sectors/track, 121575 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000c3b74

   Device Boot Start End Blocks Id System
/dev/sdc1 * 1 262 2104483+ 83 Linux
/dev/sdc2 263 2352 16787925 82 Linux swap / Solaris
/dev/sdc3 2353 121575 957658747+ 8e Linux LVM

Disk /dev/md0: 60.0 GB, 60022325248 bytes
32 heads, 32 sectors/track, 114483 cylinders
Units = cylinders of 1024 * 512 = 524288 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000cb60c

    Device Boot Start End Blocks Id System
/dev/md0p1 1 114484 58615640 fd Linux raid autodetect

# pvs
  PV VG Fmt Attr PSize PFree
  /dev/md0p1 vgssd lvm2 a- 55.90g 20.90g
  /dev/sdc3 vgsata lvm2 a- 913.29g 849.29g

# lvs
  LV VG Attr LSize Origin Snap% Move Log Copy% Convert
  home vgsata -wi-ao 4.00g
  mysql.bak vgsata -wi-ao 10.00g
  sysbak vgsata -wi-a- 50.00g
  mysqldump vgssd -wi-ao 10.00g
  usr vgssd -wi-ao 5.00g
  var vgssd -wi-ao 20.00g

# mdadm -E --scan
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=8035e4aa:c77c9788:e368bf24:bd0fce41

# cat /etc/mdadm/mdadm.conf
DEVICE partitions
CREATE owner=root group=disk mode=0660 auto=yes
HOMEHOST <system>
MAILADDR root
# This file was auto-generated on Mon, 29 Apr 2013 15:25:47 -0500
# by mkconf $Id$
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=8035e4aa:c77c9788:e368bf24:bd0fce41

# mdadm --examine /dev/sda1
/dev/sda1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : 8035e4aa:c77c9788:e368bf24:bd0fce41
  Creation Time : Thu May 9 09:21:34 2013
     Raid Level : raid1
  Used Dev Size : 58615552 (55.90 GiB 60.02 GB)
     Array Size : 58615552 (55.90 GiB 60.02 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0

    Update Time : Wed Jun 12 10:10:19 2013
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 381900d2 - correct
         Events : 41

      Number Major Minor RaidDevice State
this 0 8 0 0 active sync /dev/sda

   0 0 8 0 0 active sync /dev/sda
   1 1 8 16 1 active sync /dev/sdb

# mdadm --examine /dev/sdb1
/dev/sdb1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : 8035e4aa:c77c9788:e368bf24:bd0fce41
  Creation Time : Thu May 9 09:21:34 2013
     Raid Level : raid1
  Used Dev Size : 58615552 (55.90 GiB 60.02 GB)
     Array Size : 58615552 (55.90 GiB 60.02 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0

    Update Time : Wed Jun 12 10:10:19 2013
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 381900e4 - correct
         Events : 41

      Number Major Minor RaidDevice State
this 1 8 16 1 active sync /dev/sdb

   0 0 8 0 0 active sync /dev/sda
   1 1 8 16 1 active sync /dev/sdb

# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdb[1] sda[0]
      58615552 blocks [2/2] [UU]

unused devices: <none>

# reboot