The HPE Alletra 9000 (and its predecessor, HPE Primera) supports various Remote Copy (RC) topologies to meet different disaster recovery and data distribution requirements. These include 1-to-1, 1-to-N (fan-out), and N-to-1 (fan-in) configurations.

In an N-to-1 Remote Copy configuration, multiple source storage systems (represented by 'N') replicate their data to a single, centralized target system at a disaster recovery (DR) or secondary site. This architecture is particularly efficient for organizations with multiple regional or branch offices that wish to centralize their backup and DR operations into a single data center to reduce hardware costs and simplify management. In the scenario described, the company has three primary sites ($N = 3$), each with its own storage array. To implement an N-to-1 strategy, the administrator only needs to provide one storage array at the DR site. This single target array must be sized appropriately to handle the combined capacity and performance requirements (IOPS and throughput) of the incoming replication streams from all three source systems.

Architecturally, the Alletra 9000 uses Remote Copy Groups to manage these relationships. Each group on the source systems is mapped to a corresponding group on the single target system. It is important to note that while the hardware requirement is a single array, the administrator must ensure the target array has sufficient Remote Copy ports (RCIP or RCFC) and licensed capacity to accommodate the fan-in ratio. The Alletra 9000 management interface and HPE GreenLake Data Services Cloud Console (DSCC) provide the orchestration necessary to monitor these multiple inbound streams and ensure that the Recovery Point Objectives (RPOs) are met across all sites simultaneously.