Interrupting and restarting automatic dump processing

You can use the following methods to interrupt automatic dump processing during the three phases of automatic dump. These three phases are:
  • Automatic deletion of expired dump copies
  • Automatic dump of DFSMShsm-managed or owned volumes
  • Deletion of excess volume table of contents (VTOC) copy data sets
There are four methods you can use to interrupt automatic dump processing:
  • Hold dump processing — You can hold dump processing by specifying the DUMP, DUMP(AUTO), or ALL parameter of the HOLD command. If you hold dump processing with the ENDOFDATASET parameter while DFSMShsm is automatically deleting expired dump copies or excess dump VTOC copy data sets, processing ends after DFSMShsm has finished processing the current dump generation. If you hold dump processing with the ENDOFVOLUME parameter while DFSMShsm is automatically deleting expired dump copies or excess VTOC copies, processing ends after the current phase of automatic dump has completed. If you hold dump processing with the ENDOFVOLUME parameter, DFSMShsm continues processing the current volumes and does not process any new volumes. Otherwise, DFSMShsm dump processing ends the next time DFSMSdss reads or writes a record. DFSMShsm does not start any new volume dump tasks.
  • Disable dump processing — You can disable dump processing by specifying the NOBACKUP parameter of the SETSYS command. If you disable dump processing while DFSMShsm is automatically deleting expired dump copies or excess dump VTOC copy data sets, processing ends after DFSMShsm has finished processing the current dump generation. If you disable dump processing while DFSMShsm is dumping DFSMShsm-managed volumes, DFSMShsm dump processing ends the next time DFSMSdss reads or writes a record. DFSMShsm does not start any new volume dump tasks.
  • Place DFSMShsm in emergency mode — You can place DFSMShsm in emergency mode by specifying the EMERGENCY parameter of the SETSYS command. If you place DFSMShsm in emergency mode while DFSMShsm is automatically deleting expired dump copies or excess dump VTOC copy data sets, processing ends after DFSMShsm has finished processing the current dump generation.

    If you are in a multiple DFSMShsm-host environment, and have enabled the secondary host promotion function, another DFSMShsm host takes over the unique functions of the primary DFSMShsm host that you have put in emergency mode. Those functions include automatic deletion of expired dump copies and excess dump VTOC copy data sets. If promotion occurs during an automatic dump window (as defined on the primary host), and it is not past the latest start time, the promoted host restarts automatic dump processing.

    If you place DFSMShsm in emergency mode while DFSMShsm is dumping DFSMShsm-managed volumes, DFSMShsm dump processing ends the next time DFSMSdss reads or writes a record. DFSMShsm does not start any new volume dump tasks.

  • Stop DFSMShsm processing — You can stop DFSMShsm by entering the MVS™ or DFSMShsm STOP command. If you shut down DFSMShsm while DFSMShsm is deleting expired dump copies or excess dump VTOC copy data sets, processing ends after DFSMShsm has finished processing the current dump generation. If you shut down DFSMShsm while DFSMShsm is dumping DFSMShsm-managed volumes, DFSMShsm dump processing ends the next time DFSMSdss reads or writes a record. DFSMShsm does not start any new volume dump tasks.

    If you are in a multiple DFSMShsm-host environment, have enabled secondary host promotion, and you have issued a STOP PROMOTE command, another DFSMShsm host takes over the unique functions of the primary DFSMShsm host that you have stopped. Those functions include automatic movement of backup versions from ML1 to tape, and automatic backup of migrated data sets. If promotion occurs during an automatic backup window (as defined on the primary host), and it is not past the latest start time, the promoted host takes over where the primary host left off. If the promoted host was an automatic backup host before being promoted, it performs backups of DFSMShsm-owned volumes after performing the automatic movement of backup versions from ML1 to tape, and automatic backup of migrated data sets. If the promoted host was not an automatic backup host before being promoted, it does not back up DFSMShsm-owned volumes.

You can restart automatic dump processing by entering the corresponding commands:
  • RELEASE DUMP or RELEASE ALL
  • SETSYS BACKUP
  • SETSYS NOEMERGENCY
  • START DFSMSHSM (MVS command)

After you restart automatic dump processing, DFSMShsm continues with the next DFSMShsm-managed volume under automatic dump control. Automatic dump restarts at the point of interruption if less than 24 hours have passed since automatic dump was last started from the beginning and if the time is still within the dump start window.

Related reading

For more information about using the secondary host promotion function, see z/OS DFSMShsm Implementation and Customization Guide.

Parent topic: Full-volume dump procedures