Comment 11 for bug 872220

I was able to reproduce one of the issues in a vmware instance. I am using ubuntu 11.10 server both 64 and 32 bit work fine. Desktop may work as well but I have seen several reports of the initiramfs shell getting blocked by the desktop UI so I through it was simpler to just start without anything graphical.

I set up a system with on system drive and 3 small drives. Once up in installed mdadm and created an array from the 3 small drives. I set up a file system added the array to fstab and mdadm.conf, rebooted to make sure everything worked as it should and it did. I shut down the system and disconnected 2 of the 3 drives and booted again. I had forgotten to set the boot degraded option so I had to manually select y when prompted, the system tried to create the array, creation failed and it dropped into the shell. I tried dropping the array from mdadm.conf and that made no difference.

It looks like there is no way to boot a system if it has one disk that reads as being part of a 3+ disk array connected to it. So it looks like there are really 2 separate issues:

(1) if you have a part of an old array or a severely degraded array connected to the system, it is not possible to boot
(2) the point at which the system checks whether this is the case or not happens way too early (for me it happens right after the 4 second mark) and misses disks that might take a while to get up and running (on a clean boot the last of my disks show up around the 5-6 second mark)

the second issue can be worked around if #1 does not exist since the disks are there and by the time the system is fully up all the disks have reported in.

I am attaching a screencap right after it drops into the shell and will also attach the complete dmesg from this error in a separate comment.