A diskarray system has a diskarray controller and a plurality of disk devices. Each of the disk devices has a media, a head, and a head position controller. The diskarray controller performs online data check operation, and stops the online data check operation over the disk device at first predetermined timing. After stopping the online data check operation, the diskarray controller issues an unload enable command to the disk device so as to move the head to a position different from positions at which the head reads or writes data from or to the media. The head position controller of the disk device moves the position of the head on the basis of the received unload enable command.