Patent ID: 8482875

Claim:
A tape library control apparatus comprising: a configuration information storage configured to store configuration information on the number of available tape drives among a plurality of tape drives and the number of specific magnetic tapes, the plurality of the tape drives and the specific magnetic tapes being included in a tape library apparatus, the available tape drives being available for writing data to and reading data from each of magnetic tapes provided therein, each of the specific magnetic tapes being assigned for respective pieces of data sent by a host computer; a diagnostic evaluator configured to determine a use mode of the tape library apparatus on the basis of comparison between the number of the specific magnetic tapes and the number of the available tape drives and to output a request in accordance with the determined use mode, the use mode being selected from a first mode and a second mode, the first mode being selected when the number of the specific magnetic tapes is higher than the number of the available tape drives, the second mode being selected when the number of the specific magnetic tapes is lower than or equal to the number of the available tape drives; and a command controller configured to output in response to the request a command to the tape library apparatus to instruct, when the use mode is determined as the first mode, to write first data to one of the specific magnetic tapes and to write the first data to a common magnetic tape provided for writing the respective pieces of the data, the first data being sent from the host computer, the one of the specific magnetic tape being assigned for the first data.