Patent ID: 8589622

Claim:
A control apparatus connectable to a memory unit for storing data sent out from a host, for controlling a first tape writing unit including a plurality of first tapes and a second tape writing unit including a plurality of second tapes so that the first and second writing units write same data stored in the memory unit into one of the first tapes and one of the second tapes, respectively, comprising: an obtaining unit to obtain a progress value indicating a progress of writing data into the one of the second tapes whose writing process is unfinished upon completely writing the data into the one of the first tapes; and a controller that to control the second tape writing unit to set a writing process priority of the one of the second tapes to be lower than a writing process priority of others of the second tapes and to continue to write the data in the memory unit into the one of the second tapes when the progress value is not more than a predetermined value.