Symmetrix Remote Data Facility (SRDF) The SRDF family of software is the gold standard for remote replication in mission critical environments. Built for the industry-leading high-end VMAX hardware architecture, the SRDF family of solutions is trusted for disaster recovery and business continuity. The SRDF family offers unmatched deployment flexibility and massive scalability to deliver a wide range of distance replication capabilities. The SRDF family consists of the following options: •SRDF/S – Synchronous option for zero data exposure loss •SRDF/A – Asynchronous option for extended distances •SRDF/Star – Multi-site replication option •SRDF/CG – Consistency Groups for federated data sets across arrays link -> http://www.emc.com/storage/symmetrix-vmax/srdf.htm