7.13.1 Function

This function defines replicas of an existing RDAREA. By defining a replica RDAREA, you can use the inner replica facility.

Prerequisites
  1. You can define a replica RDAREA without the entity of the replica HiRDB file system area as long as its generation information has been registered in the data dictionary table.
  2. When you define a replica RDAREA, we recommend that you place the original RDAREA in command shutdown and closed status.
  3. When you define a replica RDAREA, make sure that the total numbers of RDAREAs and HiRDB files do not exceed the maximum number of RDAREAs (pd_max_rdarea_no) and the maximum number of HiRDB files constituting the RDAREAs (pd_max_file_no) specified in the system common definition. If this value is exceeded, you must use the pdchgconf command to change the system common definition or terminate the HiRDB system normally and then change the system common definition.
  4. If the original RDAREA for which a replica is to be defined is a shared RDAREA, the system assumes that a replica has been defined for the RDAREA at every back-end server (even if a replica definition has not been specified for a back-end server, the system assumes that a replica has been defined). If the maximum permissible number of RDAREAs or maximum permissible number of HiRDB files constituting RDAREAs is exceeded at any back-end server, the replica definition cannot be specified for the shared RDAREA at all.
  5. When you define a replica RDAREA, make sure that the total number of original RDAREAs does not exceed the maximum inner replicas (pd_max_replica_control) specified in the system common definition. If this value is exceeded, you must use the pdchgconf command to change the system common definition or terminate the HiRDB system normally and then change the system common definition.
  6. If the original RDAREA for which a replica is to be defined is a shared RDAREA, the system assumes that a replica has been defined at every back-end server (even if no replica definition has been specified for a back-end server, the system assumes that a replica has been defined). If the maximum permissible number of inner replicas is exceeded at any of the back-end servers, the replica definition cannot be specified for the shared RDAREA at all.
  7. If you are using mirror files that apply the logical volume function to replica RDAREAs, the RDAREA open timing must be set to SCHEDULE.