1.$ SET DUMP_OPTIONS /DEVICE=DKA100:

    2.$ SET DUMP_OPTIONS /DEVICE=$77$DKA200:/LOG
      %SET-I-FILEUPDATED, SYS$MANAGER:SYS$DUMP_CONFIG.DAT updated
      %SET-I-MEMUPDATED, memory settings updated

    3.$ SET DUMP_OPTIONS /DEVICE=($77$DKA200:,DKA100:)

    In this example, DKA100: will only be used as a system dump
    device if $77$DKA200: is not accessible at the time of the
    system crash.