Abstract: In order to eliminate I/O performance bottleneck of a path in a disk array system, one expander is composed of two internal expanders connected to each other, and when the path falls in a bottleneck, connection of two internal expanders in a designated expander is cut off, and the cut-off internal expanders are connected to a new path to change access route to the disk drive. A device management table managing individual disk drives and a routing table managing access routes of respective paths are updated according to the switching of the access route.

Abstract: In order to eliminate I/O performance bottleneck of a path in a disk array system, one expander is composed of two internal expanders connected to each other, and when the path falls in a bottleneck, connection of two internal expanders in a designated expander is cut off, and the cut-off internal expanders are connected to a new path to change access route to the disk drive. A device management table managing individual disk drives and a routing table managing access routes of respective paths are updated according to the switching of the access route.

Abstract: Deterioration of performance due to diagnosis processing performed when a failure occurs is prevented. A storage apparatus 10 includes a controller 11A and a plurality of expanders 112A, 121A coupled to the controller 11A to form a first system, and includes a controller 11B and a plurality of expanders 112B, 121B coupled to the controller 11B to form a second system. The controller 11A accesses the storage drive 171 through the expanders 112A, 121A, and the second controller 11B accesses the storage drive through the expanders 112B, 121B. In the storage apparatus 10, the controller 11A stores a maximum number (concurrently-executable maximum number) of communication ports 80 that are concurrently diagnosable in the first system, and repeatedly executes a process of selecting the communication ports 80 not exceeding the concurrently-executable maximum number and a process of causing the expanders 112A, 121A to diagnose the selected communication ports 80.

Abstract: Regarding an additional storage chassis used by being connected to a basic chassis equipped with a storage controller, provided is a computer system capable of changing or updating a firmware environment of the additional storage chassis so that normal operation of the additional storage chassis can be secured on the user side even if the operation different from the operation, which was guaranteed at the time of factory shipment, is executed on the user.

Abstract: Deterioration of performance due to diagnosis processing performed when a failure occurs is prevented. A storage apparatus 10 includes a controller 11A and a plurality of expanders 112A, 121A coupled to the controller 11A to form a first system, and includes a controller 11B and a plurality of expanders 112B, 121B coupled to the controller 11B to form a second system. The controller 11A accesses the storage drive 171 through the expanders 112A, 121A, and the second controller 11B accesses the storage drive through the expanders 112B, 121B. In the storage apparatus 10, the controller 11A stores a maximum number (concurrently-executable maximum number) of communication ports 80 that are concurrently diagnosable in the first system, and repeatedly executes a process of selecting the communication ports 80 not exceeding the concurrently-executable maximum number and a process of causing the expanders 112A, 121A to diagnose the selected communication ports 80.