Magnetic disk device

An embodiment provides a magnetic disk device capable of inexpensively investigating the cause of a failure. A magnetic disk device according to an embodiment includes: a first magnetic disk; a first actuator that reads/writes data to/from the first disk; a first control unit that controls the first actuator; a second magnetic disk; a second actuator that reads/writes data to/from the second disk; and a second control unit that controls the second actuator. The first control unit executes a read/write process, and the second control unit stores trace data of the read/write process when the first control unit executes the read/write process. 实施方式提供一种能够廉价地调查故障的原因的磁盘装置。实施方式的磁盘装置具备：第1磁盘；第1致动器，对于所述第1磁盘进行数据的读/写；第1控制部，控制所述第1致动器；第2磁盘；第2致动器，对于所述第2磁盘进行数据的读/写；及第2控制部，控制所述第2致动器。所述第1控制部执行读/写处理，所述第2控制部在所述第1控制部执行所述读/写处理的情况下，存储该读/写处理的跟踪数据。