Patent ID: 8868805

Claim:
A storage device to be connected with a plurality of hosts each having a plurality host-side communication ports and a multipath driver, the storage device comprising: a plurality of logical storage units; a plurality of communication ports each of which is to be connected with one or more host-side communication ports; a driver type judging part that stores into a storage, when a prescribed SCSI command that a Target Port Group Support (TPGS) compliant multipath driver transmits but a non-TPGS-compliant multipath driver does not transmit is received by any one of the plurality of communication ports, information indicating that the multipath driver used in a host that has transmitted the prescribed SCSI command is the TPGS-compliant multipath driver; a command processing part that processes each SCSI command received by the plurality of communication ports, wherein the command processing part, with respect to a SCSI command received via a communication path that is set by a user as a standby path, judges by referring to the storage whether or not a TPGS compliant multipath driver is used in a host that transmitted the SCSI command, and, if the TPGS compliant multipath driver is used in the host, sends back to the host a sense indicating that the communication path is the standby path, and, whereas if the TPGS compliant multipath driver is not used in the host, processes the SCSI command assuming that the communication path is not the standby path.