1. A system in communication with a host computer, comprising: memory; and processor coupled to the memory, wherein the processor is configured to perform operations, the operations comprising: (i) detecting a change in a configuration of a plurality of logical subsystems; (ii) sending a notification, wherein the notification indicates the change in the configuration of the plurality of logical subsystems; and (iii) receiving data transfer requests directed at available logical subsystems, wherein the available logical subsystems are determined based on the configuration of the plurality of logical subsystems, wherein the system is a storage control unit, and wherein the operations further comprise: (a) generating a data structure to keep track of the available logical subsystems in the storage control unit; (b) creating a new logical subsystem in the storage control unit, wherein the creating of the new logical subsystem causes the change in the configuration of the plurality of logical subsystems; (c) updating the data structure to indicate that the new logical subsystem is available; and (d) indicating in the notification that the new logical subsystem is available, wherein the host computer receives the notification, wherein the host computer attempts to establish a previously rejected logical path for data transfer by using the new logical subsystem, and wherein the host computer establishes a logical path for data transfer to the new logical subsystem.