A refrigerator door is provided. Traffic smoothing may comprise a method for controlling data transmission in a communications system that further comprises scheduling the timing of transmission of information from a TCP offload engine based on a traffic profile. The storage system controller then recognizes a second drive failure and enters a second operating mode, which is different from the first operating mode, in response to the second drive failure. With such a remote copy system and a method for use therein, any data backup failure can be prevented. To this end, a quadratic equation is used for the model, which equation might default into a first order equation requiring fewer computations, in the event that no second order solutions exist.