"We saw that if our VMAX was to fail, we needed some other type of redundancy," said Eric Sato, manager of server administration at CTCA. Sato said his company is considering using VPLEX Geo and Global eventually to replicate data to its brand new secondary data center in Madison, Wis.

CTCA hired consulting firm Ahead to help it with the VPLEX implementation. Eric Kaplan, president of technical consulting at Ahead, said CTCA is not atypical of many businesses that are looking for greater resiliency.

Limitations caused by the speed of light typically cause applications to time out when data is being replicated between machines over distance. This means that if a machine sending data does not receive confirmation from the recipient machine within a certain span of time, it considers the computer operation failed.

Typically, vendors have solved this problem by sending data asynchronously over distances, so that a response message is not required from the recipient machine. Asynchronous data replication, however, means that if a disaster occurs, causing a primary data center to go down, the data in transit to the secondary data center is lost. In order to share data in real-time, synchronous replication is required.

EMC's VPLEX appliance basically cheats speed of light limitations by sending across a light-weight code with the data to invalidate the requirement for a fast response between servers in multiple sites - something EMC calls "cache coherency."