2Eugene Gorbunoff: How could reformat help him? Does it create the LVM info?
Anyway, using DFSee, as I suggested above, is non-destructive. It only writes a DLAT sector before the boot sector. After you eject and insert again the flash stick, it will be mountable, and no need to format. Using reformat formats the stick, so, its contents will be lost. What if it is other user's flash stick and he is not agree to reformat it?