System-managed duplexing of coupling facility structures. A plurality of instances of coupling facility structures are maintained in a plurality of coupling facilities. Duplexing processing associated with the plurality of instances is managed by one or more operating systems, making many of the steps associated with duplexing transparent to the exploiters of the coupling facility structures. System-managed duplexing provides high availability for coupling facility structure data via a robust recovery mechanism (i.e., duplexing failover).