Comment 9 for bug 334994

Ok, I have managed to reproduce this in a KVM here. Console output is as below, dmesg output attached:

** WARNING: There appears to be one or more degraded RAID devices **

The system may have suffered a hardware fault, such as a disk drive
failure. The root device may depend on the RAID devices being online. One
or more of the following RAID devices are degraded:
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : inactive sda5[0](S)
      1999936 blocks

md0 : inactive sda1[0](S)
      96256 blocks

unused devices: <none>
Attempting to start the RAID in degraded mode...
mdadm: CREATE user root not found
mdadm: CREATE group disk not found
[ 35.024024] kobject_add_internal failed for dev-sda1 with -EEXIST, don't try to register things with the same name in the same directory.
mdadm: failed to add /dev/sda1 to /dev/md0: File exists
mdadm: failed to RUN_ARRAY /dev/md0: Invalid argument
mdadm: Not enough devices to start the array.
[ 35.074648] kobject_add_internal failed for dev-sda5 with -EEXIST, don't try to register things with the same name in the same directory.
mdadm: failed to add /dev/sda5 to /dev/md1: File exists
mdadm: failed to RUN_ARRAY /dev/md1: Invalid argument
mdadm: Not enough devices to start the array.
Could not start the RAID in degraded mode.
Gave up waiting for root device. Common problems:
 - Boot args (cat /proc/cmdline)
   - Check rootdelay= (did the system wait long enough?)
   - Check root= (did the system wait for the right device?)
 - Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/md1 does not exist. Dropping to a shell!

BusyBox v1.10.2 (Ubuntu 1:1.10.2-2ubuntu6) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs)