EMC partnered with several companies, including , Brocade, Silver Peak and Ciena, to use their WAN optimization technologies to achieve the data replication over distance.

In a question and answer session with press and analysts, Gallagher said the box only replicates data changes or updates and can only withstand a 50-millisecond delay between servers in geographically dispersed data centers.

"When an application comes through the [storage area network], the write is committed to disk as well as replicated to the remote site," he said.

The VPLEX appliance's "secret sauce" is its ability to tell applications such as Exchange, Sharepoint, or Oracle, that they're receiving the data in real time.

Cancer Treatment Centers of America (CTCA) just went live with EMC's VPLEX Metro technology. The hospital system is using VPLEX for high availability between redundant SANs -- an EMC VMAX Symmetrix and an NS960 array -- in the same rather than failing over to a secondary site - for now.