Is this a GPT partition table? Both the primary and backup GPT tables are corrupt. Or perhaps you deleted the GPT table, and are now using an msdos partition table. Perhaps it was corrupted - possibly by a program that doesn't understand GPT partition tables. However, it does not have a valid fake msdos partition table, as it should. dev/xxx contains GPT signatures, indicating that it has a GPT table. Ubuntu images (and potentially some other related GNU/Linux distributions) have a peculiar format that allows the image to boot without any further modification from both CDs and USB drives.Ī consequence of this enhancement is that some programs, like parted get confused about the drive's format and partition table, printing warnings such as: