Transitioning from a donor four site data replication system to a target four site data replication system

Abstract

Transitioning from using a donor four site replication system to using a target four site replication system includes initiating synchronization between a first local storage system of the donor four site replication system that receives I/O from a host with an alternative first local storage system of the target four site replication system, the host switching to automatically fail over to a synchronous storage system of the target four site replication system that receives synchronous data from the alternative first local storage system following synchronizing the first local storage system with the alternative first local storage system, and the host switching to perform I/O operations with the alternative first local storage system following switching to automatically fail over to the synchronous storage system. The host may run the z/OS operating system. The host may automatically fail over to a storage system by switching subchannel sets.

Dependencies are inferred from the claim text.