Abstract: Provided are a storage device, a storage system, and the like which reduce, in data migration between storages, an impact on a system and the like which use data stored in the storage device. The storage device includes: a storage unit to include a storage region which stores data, a management table storage unit to retain a management table retaining identification information relating to the storage region, access state information relating to accessibility to the storage region, and migration information indicating a state relating to migration of data stored in the storage region, and a control unit to change the access state information in accordance with a state of the data migration, based on an instruction from a management device managing migration of the data.

Abstract: A computer system according to the present invention includes: a switch which transfers test data to a different switch via each of a plurality of networks to obtain a transfer performance of each of the plurality of networks; and a controller which configures a flow entry onto a flow table of the switch, the flow entry defining a network with a transfer performance equal to or higher than a threshold value as a transfer route to the different switch. This achieves load balancing in the computer system by using the OpenFlow technology.

Abstract: A management device includes a failure detection unit 10 which detects a failure in a plurality of paths connecting servers, on at least one of which a virtual machine operates, with a storage device, a specifying unit 11 which specifies the virtual machine operating on the failed server that is the server connected by the path in which the failure is detected, a redundancy calculation unit 12 which calculates, for each of the servers, a first redundancy degree of the server with respect to the storage device, a selection unit 13 which selects, among the servers, a server having the degree of redundancy higher than the degree of redundancy of the failed server on the basis of the first redundancy degrees of the servers, and a transmission unit 14 which transmits migration instruction information including an identifier of the specified virtual machine and an identifier of the selected server.

Abstract: A computer system according to the present invention includes: a switch which transfers test data to a different switch via each of a plurality of networks to obtain a transfer performance of each of the plurality of networks; and a controller which configures a flow entry onto a flow table of the switch, the flow entry defining a network with a transfer performance equal to or higher than a threshold value as a transfer route to the different switch. This achieves load balancing in the computer system by using the OpenFlow technology.

Abstract: A management device comprises a failure detection unit 10 which detects a failure in a plurality of paths connecting servers, on at least one of which a virtual machine operates, with a storage device, a specifying unit 11 which specifies the virtual machine operating on the failed server that is the server connected by the path in which the failure is detected, a redundancy calculation unit 12 which calculates, for each of the servers, a first redundancy degree of the server with respect to the storage device, a selection unit 13 which selects, among the servers, a server having the degree of redundancy higher than the degree of redundancy of the failed server on the basis of the first redundancy degrees of the servers, and a transmission unit 14 which transmits migration instruction information including an identifier of the specified virtual machine and an identifier of the selected server.

Abstract: A storage system includes: an access path management unit managing a state of each access path for each logical disk; an I/O speed calculation unit storing, for each of the access paths, a data size and required time obtained when an I/O is executed, and calculates an I/O speed for every calculation cycle; a path candidate selection unit selecting an access path in the available state as an I/O use candidate; and a path candidate exclusion unit which excludes access paths of which speed is slow from the candidates, using a highest speed value among the speed values of the access paths selected as candidates, and the access path management unit sequentially changes the states of the access paths, out of the remaining candidates, to the I/O use states, in order of the I/O speed from the fastest until the number of access paths reaches the maximum number of paths.

Abstract: A storage system includes: an access path management unit managing a state of each access path for each logical disk; an I/O speed calculation unit storing, for each of the access paths, a data size and required time obtained when an I/O is executed, and calculates an I/O speed for every calculation cycle; a path candidate selection unit selecting an access path in the available state as an I/O use candidate; and a path candidate exclusion unit which excludes access paths of which speed is slow from the candidates, using a highest speed value among the speed values of the access paths selected as candidates, and the access path management unit sequentially changes the states of the access paths, out of the remaining candidates, to the I/O use states, in order of the I/O speed from the fastest until the number of access paths reaches the maximum number of paths.

Abstract: A communication system capable of identifying a path where a fault has occurred when the fault is detected. The communication system has a host computer with a host port, a switch with a switch port and a storage device with a storage port which is connected to the host port via the switch port. The host computer manages access path information indicating how the host port and the storage port are connected to the switch port, and identifies an access path influenced by a switch fault according to the access path information when the switch fault occurs.

Abstract: A computer includes a priority storage part to store priority information which includes priority, the priority being set in advance per each of plural paths connecting a plurality of virtual servers and one or more storage devices, and per each kind of input/output command issued to the storage device by the virtual server, and a path management unit which selects a path out of the plural paths to destination of the input/output command on the basis of the kind of input/output command and the priority information and issues the input/output command to the selected path.