man(1) Manual page archive


     HS(4)                                                       HS(4)

     NAME
          hs - RH11/RS03-RS04 fixed-head disk file

     DESCRIPTION
          The files hs0 ... hs7 refer to RJS03 disk drives 0 through
          7.  The files hs8 ... hs15 refer to RJS04 disk drives 0
          through 7.  The RJS03 drives are each 1024 blocks long and
          the RJS04 drives are 2048 blocks long.

          The hs files access the disk via the system's normal buffer-
          ing mechanism and may be read and written without regard to
          physical disk records.  There is also a `raw' inteface which
          provides for direct transmission between the disk and the
          user's read or write buffer.  A single read or write call
          results in exactly one I/O operation and therefore raw I/O
          is considerably more efficient when many words are transmit-
          ted.  The names of the raw HS files begin with rhs. The same
          minor device considerations hold for the raw interface as
          for the normal interface.

          In raw I/O the buffer must begin on a word boundary, and
          counts should be a multiple of 512 bytes (a disk block).
          Likewise lseek calls should specify a multiple of 512 bytes.

     FILES
          /dev/hs?, /dev/rhs?