Magnetic disk device

A magnetic disk device comprising:

• a disk having a first data track and a second data track adjacent to each other in a recording layer, the first data track and the second data track each including a plurality of target sectors being targets to which data are to be written, an n-th target sector of the first data track being adjacent to an n-th target sector of the second data track in a radial direction of the disk, the first data track being located in a first direction parallel to the radial direction with respect to the second data track;
• a head including a write head writing data to the recording layer and a read head reading data from the recording layer;
• a read processing unit which derives position information on the write head in the radial direction by seeking the read head and which reads the data written to the recording layer;
• a write processing unit which executes write processing of writing data to the recording layer, and setting a target position of the write head in the radial direction to a reference radius position when writing data to the n-th target sector of the second data track;
• an adjustment unit capable of adjusting a current first assurance position which is located in the first direction relative to the reference radius position, and a current first write suspending position which is located between the reference radius position and the current first assurance position, the current first assurance position being a limit position of the write head, which assures enabling data of the n-th target sector of the first data track to be read, the current first write suspending position being a limit position of the write head in the first direction where writing data to the n-th target sector of the second data track can be permitted;
• and
• a determination unit,
• wherein
• when the determination unit determines that data has been written to the n-th target sector of the second data track,
• the adjustment unit is capable of tightening each of the current first assurance position and the current first write suspending position and updating the positions to positions displaced towards the reference radius position side, and
• when the determination unit further determines that the position of the write head has exceeded the current first write suspending position,
• the write processing unit suspends write processing.