RAREPL(8)                                               RAREPL(8)

          rarepl, rarct - replace bad blocks on MSCP disks

          /etc/rarct [ -c ] [ -h ] special ...
          /etc/rarepl special lbn ...

          Rarct prints status information about MSCP disk drives
          (drives such as the RA60 and RA81 on controllers like the
          UDA50).  Normally the replacement table (RCT) is listed, as
          lines of the form

               rbn: flags: lbn

          where rbn is the replacement block number, lbn is the logi-
          cal block number replaced by rbn, and flags are constructed
          from the following bits:

          01   alternate (not primary) replacement block
          02   normal, allocated replacement block
          04   this replacement block is bad
          010  this replacement block does not exist

          Entries whose flags are zero, indicating a good, unused
          replacement block, are not listed.

          The -h option prints some header data from the first block
          of the RCT.  UNIX makes no use of this info.  -c prints
          geometry info for the drive.  Either option suppresses the
          RCT listing.

          Rarepl causes logical block lbn on device dev to be marked
          as bad and replaced.  The nearest available replacement
          block is used.  The contents of lbn are copied into the
          replacement block if possible; if lbn is unreadable, the
          replacement block is initialized with zeroes.

          Both programs work only on the raw devices.  Rarepl should
          be used only on a device which covers the entire drive (usu-
          ally partition 7).


          On the UDA50, the RCT exists only so programs in the host
          can look at it; the controller ignores its contents.  There
          is no way to read the controller's `real' forwarding data,
          only a way to set it for a particular block.  Hence if the

     RAREPL(8)                                               RAREPL(8)

          RCT is corrupted, the disk may still be used, but must be
          reformatted before additional bad blocks are remapped.