z/OS Global Mirror
z/OS® Global Mirror (previously known as Extended Remote Copy or XRC) provides a long-distance remote copy solution across two sites for open systems and IBM® Z data with asynchronous technology.
The DS8000 series supports the z/OS Global Mirror function on IBM Z hosts, only. The Global Mirror function mirrors data on the storage system to a remote location for disaster recovery. It protects data consistency across all volumes that you define for mirroring. The volumes can be on several different storage systems. The z/OS Global Mirror function can mirror the volumes over several thousand kilometers from the source site to the target recovery site.
With Global Mirror, you can suspend or resume service during an outage. You do not have to end your current data-copy session. You can suspend the session, and then restart it. Only data that changed during the outage must be synchronized again between the copies.