Patent ID: 8327041

Claim:
A storage device configured to be connected to a tape library and a host device, the tape library including a plurality of tapes holding data, the storage device comprising: a memory that stores data read from the tapes to transfer the read data to the host device and a storage section; a receiving section to receive a request for data held in one of the tapes from the host device; a first determining section to determine whether the requested data is stored in the storage section on a basis of the request received by the receiving section; a reading section to read the requested data in a predetermined amount from the tape holding the requested data and provide the read data to the memory in a case where the first determining section determines that the requested data is not stored in the storage section, the reading section includes a first reading section and a second reading section in a dual structure; a transferring section to transfer, to the host device, the read data provided to the memory by the reading section while writing, on the storage section, the read data provided to the memory by the reading section, the transferring section includes a first transferring section and a second transferring section in a dual structure; a second determining section to determine whether the requested data is held in each of the plurality of tapes; and a third determining section to determine whether the first reading section and the second reading section satisfy a condition of being able to read the requested data from different tapes of the plurality of tapes; wherein, in a case where the second determining section determines that the requested data is held in the plurality of tapes and where the third determining section determines that the first reading section and the second reading section satisfy the condition of being able to read the requested data from the different tapes, the first reading section and the second reading section read the requested data in the predetermined amount from the different tapes holding the requested data, and wherein the first transferring section writes the requested data read by the first reading section on the storage section, and the second transferring section transfers the requested data read by the second reading section to the host device.