Failure of the local storage system and of the local system

If the local system fails completely, processing can be continued on the standby system. If the home pubset of the local system has been duplicated with REC, and if the standby system is to be started with the same home pubset, a further system with SHC-OSD is required to activate the target path before startup (/HOLD-REMOTE-COPY for the volumes of the home pubset).
Data may be inconsistent if the remote link or the target unit had already failed before the local system failed.
A suitably configured and active StorMan server must be available to execute the actions of SHC-OSD.

Actions on the standby system

1. Use /ATTACH-DEVICE to attach the target units (see the “Commands” manual [1]).

2. Activate the target path (set target units to READY).
   If the remote storage system contains only target units which are affected by the failure, the entire remote storage system can be specified. Switchover takes place simultaneously for all the devices affected.

   /HOLD-REMOTE-COPY UNIT=*BY-STORAGE(SERIAL-NUMBER=<local serialnumber>
     ,LOGICAL-VOLUMES=*ALL-SOURCE-UNITS)
   

   For this function, the values DETACHED-DEVICES=*ACCEPT and NOT-DEFINED-DEVICES=*ACCEPT must be set for SYSTEM-ADMIN-SCOPE or TASK-ADMIN-SCOPE.

   If not all target units of the remote storage system are affected by the failure, all defined BS2000 volumes, all attached BS2000 volumes or the units can optionally be specified separately by means of their MN.

   The *BY-VOLUME operand can only be used if the source unit was accessible, i.e. the VSN could be read there. The *BY-PUBSET operand cannot be used for the switchover because of the failure.

3. Check data integrity (see "Data integrity after a failure").

4. Import the pubsets on the target units and start the applications.