To enable storage replication over a 20 km distance between two HPE 3PAR StoreServ 9000 All-Flash Arrays, the appropriate license required is HPE 3PAR Remote Copy. Remote Copy is HPE's replication technology that allows data to be replicated between 3PAR arrays, providing disaster recovery capabilities. This feature supports both synchronous and asynchronous replication modes, ensuring data integrity and availability in case of a failure at the primary site. The license is essential for setting up and managing the replication process over the dark fiber link. References: * HPE 3PAR StoreServ Remote Copy * HPE Storage Replication Solutions