no bootblock access is available
    Facility: EFI$CP, The OpenVMS EFI Partition Control Program
    Explanation: attempts to access the bootblock data structures
    stored in LBN0 via virtual I/O and the GPT.SYS or INDEXF.SYS
    files and via direct logical I/O read access for LBN0 have
    failed. This prevents the determination of the target bootblock
    architecture, and any other similar derivative information.
    User Action: Please target a disk with accessable GPT.SYS
    or INDEXF.SYS structures, or please operate from within a
    process context possessing LOG_IO privilege or other necessary
    privileges.