Good post by George Crump (thank you)
The ability to replicate data between data centers as it changes is an essential ingredient of any enterprise class storage system. Data centers count on this capability as the foundational component in their disaster recovery (DR) plans. But this foundation is undergoing several seismic shifts that are making the very foundation of DR unstable and combined, and may cause the entire DR strategy to collapse. A DR plan failure can mean loss of revenue, regulatory fines and eventually may cause the failure of the business.
Read on here