VMS Help ANALYZE, /MEDIA, Qualifiers, /BAD_BLOCKS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  /BAD_BLOCKS[=LIST]

   Adds the specified bad blocks to the detected bad block file
   (DBBF). If the /BAD_BLOCK qualifier is specified along with the
   /EXERCISE qualifier, the medium is tested once the bad blocks are
   added to the DBBF.

   If you do not specify a value for the /BAD_BLOCK qualifier, you are
   prompted as follows:

        BAD_BLOCKS =

   In prompt mode, BAD reports any duplicate bad blocks.

   Qualifier Value

   List

        Specifies the bad block locations to be added to the DBBF. Valid
        codes for specifying bad block locations are:

        Code                  Meaning

        LBN                   Specifies the logical block number (LBN)
                              of a single bad block.

        LBN:count             Specifies a range of contiguous bad blocks
                              starting at the logical block number (LBN)
                              and continuing for "count" blocks.

        SEC.TRK.CYL           Specifies the physical disk address (sector,
                              track, and cylinder) of a single bad
                              sector. This code is valid only for last
                              track devices.

        SEC.TRK.CYL:count     Specifies a range of bad sectors starting
                              at the specified physical disk address
                              (sector, track, and cylinder) and continuing
                              for "count" sectors. This code is valid
                              only for last track devices.

                              You can specify these formats in any
                              integer combination or radix combination.

                                   Note

           The term "block" denotes a standard unit of 512
           bytes, whereas the term "sector" denotes the
           physical size of the device sector, which is not
           always the same for all devices. For example, an
           RL02 has a sector size of 256 bytes, while an RK07
           has a standard sector size of 512 bytes.