Executor count is greater than number of  tape  drives  or  disk
  directories.

  Explanation:   The  number  of  executors  specified  with   the
  Executor_Count  qualifier  is  greater  than  the number of tape
  drives or disk directories listed with the backup file parameter
  for  a  parallel  backup command.  For this error, a tape master
  and its  slave  are  considered  one  tape  drive.   The  unused
  executors are ignored.

  User Action:  Decrease the number of executors or add more  tape
  drives or disk directories to the operation.