Comment 6 for bug 1196693

I'm currently testing this in a 14.04.1 virtual machine.
After disconnecting one HDD, boot stays on "Waiting for encrypted source device...", then drops to a shell (tried a few times before looking into it).
/proc/mdstat shows the array is assembled, but not been started. Manually starting it (with `mdadm -R`) was successful, so I rebooted to try again.. it booted fine degraded has done every boot since (below output is after booting degraded).

My setup is:
2 HDDs. Each contains 1 partition which is part of a RAID1 array (md0).
md0 is LVM with a VG called "system".
"system" contains 2 LVs, boot (unencrypted), root (LUKS)

# mount | grep /dev/m
/dev/mapper/system-root_crypt on / type xfs (rw)
/dev/mapper/system-boot on /boot type ext4 (rw)

# mdadm --detail /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Mon Jan 5 20:56:33 2015
     Raid Level : raid1
     Array Size : 20952960 (19.98 GiB 21.46 GB)
  Used Dev Size : 20952960 (19.98 GiB 21.46 GB)
   Raid Devices : 2
  Total Devices : 1
    Persistence : Superblock is persistent

    Update Time : Wed Jan 7 16:28:18 2015
          State : clean, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

           Name : ubuntu-raid1:0 (local to host ubuntu-raid1)
           UUID : 66eefd8b:ad7f449d:73d180a0:cbcabb44
         Events : 187

    Number Major Minor RaidDevice State
       0 8 1 0 active sync /dev/sda1
       1 0 0 1 removed