The quoted error message is generated by the nash
script run by the Initial RAM Disk image loaded by the GRUB stage 2 process, and occurs after
GRUB has finished and passed control to the nash
script to load the actual kernel. Therefore it is not related to the MBR nor GRUB.
The specific error message is generated when the nash
script executed a pvscan
to find all volume groups on all partitions on all drives on the computer. It means, of course, that it could find no volume groups at all. That implies either that the Logical Volume partition is "hosed," or that it has been corrupted. (For example, running fsck
on a logical volume partition will destroy all volume groups in the logical volume. [Been there, done that, got the T-shirt.
I can't tell you what caused your LV partition to "barf," but I suggest that you download and burn one of the "rescue" live CDs and see if you can recover the partition. (I like the System Rescue Live CD
, but there are many others available.)