Magnetic disk device with dummy write function

A method of controlling a magnetic disk device having a plurality of magnetic recording disk surfaces supported rotatably and storing discretely reproducible servo information,

• a plurality of magnetic heads for performing an information read/write operation for said plurality of respective magnetic recording disk surfaces,
• a rotary actuator for positioning one of said plurality of magnetic heads relative to one of said plurality of magnetic recording disk surfaces on the basis of embedded-servo information, and
• a controller for sending out a signal for selecting one of said plurality of magnetic heads and a signal commanding an information writing operation, the method comprising:
• a first step for reading a servo information from one of said plurality of magnetic recording disk surfaces;
• a second step for positioning said actuator;
• a third step for selecting a magnetic head from said plurality of magnetic heads;
• a fourth step for writing information at least once;
• a fifth step for selecting another magnetic head different from said previously selected magnetic head;
• and
• a sixth step for reading consecutive servo information.

A controlling method of a magnetic disk device having an actuator based on an embedded-servo scheme, a plurality of magnetic recording disk surfaces supported rotatably and storing discretely reproducible servo information, a plurality of magnetic heads for performing information read/write operation respectively for said plurality of magnetic recording disk surfaces, an actuator for positioning one of said plurality of magnetic heads relative to one of said plurality of magnetic recording disk surfaces on the basis of said servo information, and a controller for sending out a signal for selecting one of said plurality of magnetic heads and a signal commanding an information writing operation, the method comprising:

• a first step for reading a servo information from one of said plurality of magnetic recording disk surfaces by one magnetic head of said plurality of magnetic heads;
• a second step for selecting another magnetic head from said plurality of magnetic heads;
• a third step for writing information at least once on a corresponding disk by the selected magnetic head selected in the second step;
• and
• a fourth step for changing over from the selected magnetic head to the one magnetic head in the first step to read a second servo information from the one of said plurality of magnetic recording disk surfaces.

A method of controlling a magnetic disk device having a plurality of magnetic recording disks supported rotatably and storing discretely reproducible servo information,

• a plurality of magnetic heads for performing an information read/write operation for said plurality of respective magnetic recording disk surfaces,
• a rotary actuator for positioning one of said plurality of magnetic heads relative to one of said plurality of magnetic recording disk surfaces on the basis of embedded-servo information, and
• a controller for sending out a signal for selecting one of said plurality of magnetic heads and a signal commanding an information writing operation, the method comprising:
• a first step for reading a servo information from one of said plurality of magnetic recording disk surfaces;
• and
• a second step for writing information at least twice upon reading second servo information.