Hitachi, Ltd.

Yoshifumi Mimata

Yoshiaki Eguchi

Naoya Hattori

Yoshihiro Oikawa

Takashi Itoyama

Ikuya Yagisawa

Yuko Matsui

Shintaro Kudo

Susumu Fujii

Provided is a storage system capable of avoiding the increase in communication between nodes in the coordination of the file service and the block service. This is a storage system in which a plurality of nodes, which provide a file service for performing I/O in file units and a block service for performing I/O in block units, are connected via a network, and the storage system comprises a management unit which manages the first file processing unit and the second file processing unit as a pair, sets the first file processing unit to be operable, manages the first block processing unit and the second block processing unit as a pair, and sets the first block processing unit to be operable.

Storage system node communication

Storage system and method of storing data in nodes

A receiving controller which receives a read request out of first and second storage controllers transfers the read request to an associated controller which is associated with a read source storage area out of the first and second storage controllers when the receiving controller is not the associated controller. It is however the receiving controller that reads the read-target data from a read source storage device, writes the read-target data to a cache memory of the receiving controller, and transmits the read-target data written in the cache memory of the receiving controller to a host apparatus.

Storage system and cache control method

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.

Access route switching method in disk array system

Each communication path between controllers and a plurality of storage devices has a plurality of expanders coupled in series. In order to shorten the time during which the communication path is not used for I/O, either (A) the length of time for which I/O suppression is set for the communication path is shortened, or (B) the overall time it takes for processing other than I/O processing is shortened. In the (A), a determination as to whether or not the coupling between the expanders has been disconnected is made for the I/O-suppressed communication path, and in a case where the result of this determination is negative, a discover process is carried out after releasing the I/O suppression with respect to this communication path. In the (B), the number of command issue times of updating routing control information of the expander is reduced.

Storage system having SAS as its backend communication standard

Deterioration of performance due to diagnosis processing performed when a failure occurs is prevented. A storage apparatusincludes a controllerA and a plurality of expandersA,A coupled to the controllerA to form a first system, and includes a controllerB and a plurality of expandersB,B coupled to the controllerB to form a second system. The controllerA accesses the storage drivethrough the expandersA,A, and the second controllerB accesses the storage drive through the expandersB,B. In the storage apparatus, the controllerA stores a maximum number (concurrently-executable maximum number) of communication portsthat are concurrently diagnosable in the first system, and repeatedly executes a process of selecting the communication portsnot exceeding the concurrently-executable maximum number and a process of causing the expandersA,A to diagnose the selected communication ports

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Tokyo, Japan

Yoshifumi Mimata