A band saw blade includes multiple saw teeth having a straight tooth and right and left set teeth, and also includes a gullet portion provided between the saw teeth. When one disk device out of a plurality of disk devices constituting the RAID configuration fails, the processing size for one time of RebuildCopy back to reconstruct the RAID is changed according to the presence of a normal IO managed in RAID control. Such treatment will result in a reduction or delay in the decrease of the concentration of functionally active neuronal NPY. The lower quality data stream was encoded at a bit rate below a transmission rate.