Patent ID: 7571289

Claim:
A disk array device, comprising: an upper-level interface control unit that controls the exchange of data with a plurality of host devices respectively via a communication port; a lower-level interface control unit that controls the exchange of data with a storage device; a memory portion that is shared by the upper-level interface control unit and the lower-level interface control unit; a logical volume provided on the storage device that can be accessed via the communication port; an exclusive control information storage region that stores exclusive control information for exclusive usage of the logical volume via the communication port by a host device of the plurality of host devices, wherein the exclusive control information includes an identifier of the logical volume, a reserve state indicator that indicates whether the logical volume is reserved, path information for establishing a reservation, a persistent state indicator that indicates whether the logical volume is reserved via a plurality of preset access paths, path information for establishing a persistent reservation, an access path state indicator that indicates whether to deny usage of an access path when a fault occurs in the access path, path information for an access path state, and a state change indicator that indicates that the reserved state of the logical volume has been cancelled; an exclusive control unit provided in the upper-level interface control unit that executes exclusive control of the logical volume based on the exclusive control information, wherein the host device has exclusive usage of the logical volume; a display unit that displays predetermined information relating to the exclusive usage of the logical volume, based on all or part of the exclusive control information, wherein when the host device undergoes a system shutdown due to the host device being in a fault condition, a user confirms the predetermined information displayed on the display unit, and issues a cancellation instruction to cancel the exclusive usage of the logical volume; and a cancellation control unit, wherein upon detecting the cancellation instruction, the cancellation unit cancels the exclusive usage of the logical volume by updating the exclusive control information to indicate that the exclusive usage of the logical volume is cancelled, wherein the host device undergoing the system shutdown is unable to cancel the exclusive usage of the logical volume.