Magnetic disk device

A method of performing a write operation in a magnetic disk device comprising a magnetic disk that includes a plurality of concentric tracks and a plurality of servo sectors disposed at intervals on the plurality of tracks, and a magnetic head configured to perform writing to and reading from the magnetic disk, said method comprising:

• during a write operation for a first section of a first track among the plurality of tracks, which is a write target section:
• executing an integration operation each time the magnetic head passes through a servo sector so long as a positioning error amount in a servo sector that was most recently passed through by the magnetic head is within a range of a first positioning error threshold value, the integration operation including calculating an integrated offset amount by adding up positioning error amounts in two or more servo sectors including at least the servo sector that was most recently passed through by the magnetic head among all of the servo sectors that were passed through by the magnetic head during the write operation for the first section;
• and
• executing a first protection operation for protecting data of a second track adjacent to the first track among the plurality of tracks based on the integrated offset amount.