What is MetroCluster and when would you consider it?

• A. A data encryption feature.
• B. A cloud-based file sharing service.
• C. A high-speed inter-site network fabric.
• D. Disaster recovery solution enabling synchronous replication between sites for high availability and zero RPO in metropolitan distances.

Answer: (D)

MetroCluster is a disaster recovery setup that uses synchronous replication between two storage clusters at separate sites to provide very high availability and zero data loss. Because writes are confirmed at both sites before they’re acknowledged to the host, the Recovery Point Objective (RPO) is effectively zero, which is crucial for mission-critical workloads. It’s designed for metro distances where network latency is low enough to keep the two sites in lockstep, but if the sites are too far apart, maintaining true synchronous replication becomes impractical and asynchronous options are used instead.

You’d consider it when you must keep applications online and protect against site failures, with two data centers in reasonable proximity and the network and budget to support a dedicated inter-site link and coordinated failover. It’s a comprehensive DR solution for workloads like databases and virtualized environments, not a data encryption feature, a cloud file-sharing service, or simply a fast inter-site network.