Controller-based bi-directional remote copy system with storage site failover capability

摘要

A data replication system having a redundant configuration including dual Fiber Channel fabric links interconnecting each of the components of two data storage sites, wherein each site comprises a host computer and associated data storage array, with redundant array controllers and adapters. The system includes the capability of simultaneous bi-directional remote data replication which permits the system to operate in an 'extended cluster' mode, as if each of the remote storage arrays were local relative to the respective remote host. The system further includes the concept of 'home' and 'alternate' storage nodes, which provide for automatic node failover from a primary to a designated alternate node, without necessitating re-booting of the remote node. Write data transfers are potentially host retry-able at both sites; upon failure of controllers at one site, the host re-issues the same write on other site.