Enabling parallel write I/O for XRC secondary devices can improve overall data mover throughput and reduce average session delay. To enable parallel writes, the secondary logical subsystems must be configured with parallel access volumes (PAVs). Static aliases can be used, but for optimum flexibility IBM® recommends using the HyperPAV feature of IBM system storage. The use of the Dynamic Alias Management function of z/OS® Workload Manager is not recommended for XRC secondary devices.