Comment 11 for bug 22301

With Fabio's help, I've reproduced this problem in the case where a RAID has
previously been created using some of the physical volumes in question, but has
not been deleted. If this is the case for you, then I can provide you with
commands to run to work around this problem and continue with the installation.

I'm inclined to believe that this case (a non-zero superblock) can't be made
smoother in Breezy with a satisfactory level of risk, because the consequences
of an excessively cavalier change could easily be data loss.