Magnetic disk device and disk access method therefor

The present invention relates to a magnetic disk device known as a mass storage device using a magnetic disk as a storage medium, and to a disk access method therefor. Data can be transferred in a short time with the number of seeking operations reduced, and with the access unit to a magnetic disk defined as the number of sectors per track when a plurality of series of mass serial data are accessed by detecting whether or not access is performed in series according to a stored command history of the access to a plurality of series of mass storage file on a magnetic disk, and by actually accessing the magnetic disk not based on the data length requested by a command, but based on a track unit depending on the transfer state of each series when the seriality of the plurality of series is detected. Thus, the data transfer efficiency can be improved with the number of seeking operations reduced.