select MBR-only operations, or re-INITIALIZE this disk

    Facility: EFI$CP, The OpenVMS EFI Partition Control Program

    Explanation: GPT.SYS is present but apparently ill-formed or
    ill-sized.

    User Action: Use the DCL commands DIRECTORY and DUMP to determine
    if the file is present, if the file is writable, and if storage
    is allocated to all blocks of the file. In particular, try
    to DUMP/BLOCK=START=lastblock the last block of the file. (If
    this dump of the last block fails, you cannot use GPT bootstrap
    structures with this disk, and you must either select and use
    MBR-only operations or you must reinitialize the entire disk with
    a valid GPT and reload the files.)