1. In a system comprising a production environment comprising a processor and a replication environment comprising a processor, a method comprising: dynamically switching from an asynchronous replication policy to a synchronous replication policy; wherein the switching comprises: determining a lag decrement for decreasing IO transfer lag between the production environment and the replication environment; reducing the IO transfer lag by the lag decrement; and updating the current IO transfer lag based on acknowledgements received from the replication site until the reduced lag has been reached; continuing to reduce the lag by continuing to implement the reducing step, until a synchronous replication policy has been reached.