Disk drive apparatus and head switching method in a disk drive apparatus

A storage device comprising:

• a plurality of recording surfaces;
• a plurality of heads, each head opposed to one of the recording surfaces, the heads for reading data from or writing data to the plurality of recording surfaces;
• an offset quantity table which stores an offset quantity for each of the plurality of heads, each offset quantity being a value representative of the distance of the head with respect to a reference head;
• a means for determining a head switching sequence based on the offset quantity stored in the offset quantity table;
• a head sequence table which stores a predetermined head switching sequence;
• means for executing a head switching operation using the head switching sequence stored in the head sequence table;
• and
• a means for alternately executing a head switching operation according to the head switching sequence and a head switching operation according to a reverse sequence of the head switching sequence if the maximum offset quantity value is greater than a predefined value.