Cache usage optimization for remote data replication

Abstract

One or more aspects of the present disclosure relate to optimizing cache utilization in storage arrays with remote replication. When a write operation is received at a local array, write data is stored in an unmirrored cache slot rather than traditional mirrored slots. The system initiates parallel operations: a synchronous cut-through write to temporary disk space in the local array and a remote write to mirrored cache slots in a remote array. The cut-through write bypasses the backend adapter to write directly to disk, completing in microseconds compared to milliseconds for remote writes. After receiving acknowledgments from both operations, a write completion is sent to the host. The system maintains fault tolerance through multiple redundancy mechanisms while reducing DRAM usage from four copies to three across the primary and secondary arrays.