Patent ID: 7190537

Claim:
A self-RAID (Redundant Array of Inexpensive Disks) system, the self-RAID system comprising: a hard disk drive with at least one writable and readable disk medium; a spindle motor rotating the at least one disk medium; a plurality of heads; an actuator arm driving the heads; and a controller controlling the heads to write data to and read data from the at least one disk medium using a mode selection signal, wherein the controller examines the mode selection signal, controls a first head and a second head of the plurality of heads to write the same data to and read the same data from the at least one disk medium when the hard disk drive operates under a self-RAID mode, and controls the first head and the second head of the plurality of heads head to write different data to and read different data from the at least one disk medium when the hard disk drive operates under a normal mode, wherein the first head is a primary head and the second head is a backup head, and wherein the controller is a microcontroller controlled by firmware, and during a data write operation, the backup head writes data written by the primary head to a backup position that is different from a write position to which the primary head writes data whereas during a data read operation, if the primary head cannot read data written to the write position, the backup head reads data written to the backup position and the primary head rewrites read data in another write position.