Dell SRDF Introduction

Cascaded SRDF/Star

In cascaded SRDF/Star, production data on R1 devices at Site A is synchronously replicated to R21 devices at Site B. Then, the data is asynchronously replicated to R2 devices at Site C. The synchronous secondary site (Site B) is always more current than the asynchronous tertiary site (Site C). If the synchronous secondary site fails, the cascaded SRDF/Star solution can incrementally establish an SRDF/A session between the primary site and the asynchronous tertiary site.

Cascaded SRDF/Star can determine when the current active R1 cycle (capture) contents reach the active R2 cycle (apply) over the long-distance SRDF/A links. It minimizes the amount of data that must be moved between Site B and Site C to fully synchronize them.

This example shows a basic cascaded SRDF/Star solution.