Metro/Global Copy is a cascaded PPRC solution that enables you to combine two PPRC pairs, synchronous PPRC and PPRC-XD, which operates asynchronously, to create a low-cost, long-distance, tier four data loss disaster recovery configuration. In a cascading PPRC configuration, a single volume is defined as both a primary and a secondary, combining three volumes into two PPRC pairs.
For additional information about Metro/Global Copy, refer to Metro/Global Copy.