Lucid cannot boot from filesystems with multiple signatures

[Chris Jones]

Having upgraded a Dell PowerEdge from hardy to lucid we found it unable to boot, instead falling to an initramfs with an error that it couldn't find the root filesystem.
blkid -p on the boot device claimed ambivalent results due to multiple filesystem signatures.

Simply removing the (two) incorrect VFAT signatures on the device with wipefs allowed the system to boot normally.

[Chris Jones (cmsj)]

While it is perhaps the case (as is argued in 428318) that blkid cannot be expected to be omniscient and choose the correct signature, the reality is that this is a regression in functionality and telling people to reformat is not really very good.

Perhaps it would therefore be useful for do-release-upgrade to perform a quick test to see if the mounted filesystems have ambivalent results with a new blkid and if so either refuse to upgrade until the user has fixed the situation, or if we have a high degree of trust in the tools, remove the signatures which don't match the filesystem type which the partition is actually mounted as.

[Chris Jones (cmsj)]

(fwiw the additional filesystem signatures were two VFAT ones named 'DellUtility' so presumably relate to recovery partitions that were not entirely erased when we formatted and installed Ubuntu)