Description

   The mrd_load(3mrd) function is a specialized interface to the
   SCSI Move Medium command (or DSA equivalent). For the robot
   specified by robot_name, the routine will attempt to move the
   cartridge in the specified slot to the specified drive. Element
   addresses are zero based. On subsystems that support inverting a
   cartridge during a move, the cartridge_side argument can be used
   to indicate that the cartridge should be inverted.

   The robot will be opened and the arguments to the function will
   be verified to make sure they are safe and appropriate. The slot
   and drive address will be verified they are within the valid of
   those elements on the robot.

   The volume_tag argument can be used to perform cartridge volume
   tag verification before the move. If the cartridge volume tag at
   the port doesn't match that specified by this argument, then mrd_
   load(3mrd) will fail with the status MRD_STATUS_CART_INVALID. If
   volume_tag argument is a NULL pointer, an empty string or used on
   a robot without vision support this argument is silently ignored
   and the volume tag check will not be made.