US Patent 7487292 Magnetic disk apparatus, control method and control program therefor

A magnetic disk apparatus capable of effectively achieving speedup of the response to a read request, a control method and control program therefore are provided. In a control of a magnetic disk apparatus having a RAID configuration in which the same data is written on two disks, a given algorithm is selected from a plurality of different algorithms with respect to the data stored in the disks, read commands are issued to the data stored in the two disks, respectively, according to the selected algorithm and the data that has been read first by the read commands that has been issued to the two disks in a read command issuance step is adopted as read data.