Magnetic disk device

A magnetic disk device comprising:

• a magnetic disk that includes a plurality of storage areas arranged in a radial direction;
• a magnetic head;
• a memory in which a plurality of counters, each of which corresponds to one of the plurality of storage areas, are stored;
• and
• a controller configured to execute a write operation in response to a write command, to write data to a first storage area which is one storage area among the plurality of storage areas, variably update, in response to the write operation, a value of a first counter, which is a counter corresponding to the first storage area among the plurality of counters, according to a positioning error amount of the magnetic head during the write operation, and increase a value of a counter among the plurality of counters corresponding to a second storage area, which is a storage area in the vicinity of the first storage area among the plurality of storage areas.

A method of performing a refresh operation in a magnetic disk device comprising a magnetic disk that includes a plurality of storage areas arranged in a radial direction and a magnetic head, said method comprising:

• executing a first refresh operation in response to a first trigger and executing a second refresh operation in response to a second trigger that is different from the first trigger, wherein each of the first and second refresh operations includes a seek operation to move the magnetic head to a first storage area among the plurality of storage areas, a stabilization operation to wait for attenuation of residual vibration of the magnetic head after the seek operation is completed, and a rewrite operation to rewrite all data of the first storage area to the first storage area after the stabilization operation is completed;
• decreasing a value of a counter corresponding to the first storage area in response to the rewrite operation;
• and
• increasing a value of a counter corresponding to a second storage area in response to the rewrite operation, the second storage area being a storage area in the vicinity of the first storage area among the plurality of storage areas, wherein
• the stabilization operation includes an operation to determine whether a completion condition is satisfied, and
• the completion condition is a first condition when the first refresh operation is executed and a second condition different from the first condition when the second refresh operation is executed.