Peer-to-Peer Extended Distance

When you enable the PPRC extended distance feature (PPRC-XD), the primary and recovery storage control sites can be separated by long distances. Updates made to a PPRC primary volume are sent to a secondary volume asynchronously, thus requiring less bandwidth.

If you are trying to decide whether to use synchronous or asynchronous PPRC, consider the differences between the two modes:

When you use synchronous PPRC, no data loss occurs between the last update at the primary system and the recovery site, but it increases the impact to applications and uses more resources for copying data.
Asynchronous PPRC using the extended distance feature reduces impact to applications that write to primary volumes and uses less resources for copying data, but data might be lost if a disaster occurs. To use PPRC-XD as a disaster recovery solution, customers need to periodically synchronize the recovery volumes with the primary site and make backups to other DASD volumes or tapes.

Related reading: Refer to z/OS DFSMS Advanced Copy Services for details on the PPRC extended distance feature.