Comment 58 for bug 290885

FOLLOW NOTES
- I compared the 'local' script on my 1st (successful) machine and this 2nd machine; they're identical, same file-date, same lack of 'mdadm' reference. So that's not the problem here.
- I sat and waited to see if the new "Boot degraded?" prompt appeared; it did not.
- I tried editing /etc/initramfs-tools/conf.d/mdadm and set BOOT_DEGRADED=true
  Still no success with 1 drive.
- One thing I had not done was run 'dpkg-reconfigure mdadm'. I ran it and selected the Boot Degraded option, then rebooted; failure.

Finally, I tried doing the manual workaround just to make sure my system really could boot degraded, and it did. In other words, from the Busybox prompt I typed:
  (initramfs) mdadm --assemble /dev/md0
  (initramfs) mdadm --assemble /dev/md1
Rebooted and everything worked on the 1 drive.

So I'm not sure why it didn't Just Work automatically.