HP P9000 Business Continuity Manager User Guide

4x4x4 Cascade Configuration
This configuration is a combination of a 4x4 configuration and a 3DC Cascade configuration.
Between the primary site and the intermediate site, a Continuous Access Synchronous for Mainframe
copy group is used. Between the intermediate site and the remote site, the Continuous Access
Journal for Mainframe copy group that defined an extended consistency group (EXCTG) is used.
This configuration can preserve consistency across multiple storage systems in an EXCTG.
30 Overview of HP P9000 for Business Continuity Manager Software