Extended Remote Copy or XRC is an IBM zSeries and System z9 mainframe computer technology for data replication.
It combines supported hardware and z/OS software to provide asynchronous replication over long distances.
XRC is a z/Series asynchronous disk mirroring technique which is effective over any distance.
XRC functions as a combination of disk (IBM ESS or HDS licensed) Microcode and application code running on a z/Series host and provides a recovery point that is time consistent across multiple disk subsystems.
The host component of the software is called the System Data Mover or SDM.