US Patent 10083093 Consistent replication in a geographically disperse active environment

A method, system, and program product for enabling a virtual service layer to consume a storage medium of a first site and a storage medium of a second site, enabling the virtual service layer to map the storage mediums of the first and second sites as one or more virtual storage volumes, wherein the one or more storage volumes are mirrored between the first and second site, and enabling the virtual service layer to create a write order fidelity delta set of the virtual storage volumes by writing the delta set to backend storage and notifying a splitter to which delta set the IO belongs.