Global storage virtualization and a virtual storage machine are used as foundational features for global-active device. GAD enables you to create and maintain synchronous, remote copies of data volumes. Both volumes of a GAD pair can receive the same data from the server.
When you use GAD, a resource group is created in the secondary storage system, and the model type and serial number of the primary storage system are assigned to the resource group to create the virtual storage machine. The server then recognizes both storage systems (the storage systems at the primary and secondary sites) as the same storage system and can synchronously access both volumes of a GAD pair.