What is cascading SnapMirror and why is it used?

• A. Cascading SnapMirror copies data from primary directly to tertiary only.
• B. Cascading SnapMirror replicates from a primary to a secondary site and then to a tertiary site to extend DR coverage.
• C. Cascading SnapMirror automatically compresses data during transfer.
• D. Cascading SnapMirror backs up data to tape.

Answer: (B)

Cascading SnapMirror is a replication pattern where data is sent from the primary array to a secondary array, and that secondary array then replicates onward to a tertiary array. This creates a chain of replicas that extends disaster recovery coverage to additional sites without the primary having to connect to every remote site. The main advantage is scalability and bandwidth efficiency: each link carries data only to the next hop, reducing load on the central source and enabling local DR copies at remote locations for faster failover. It differs from a simple one-to-one setup, which can be hard to scale and may place more strain on the primary. It isn’t about automatic data compression or taping backups, so those options don’t describe what cascading SnapMirror does.