Patent ID: 7461202

Claim:
In a computer configuration comprising a hard disk drive having at least one magnetic disk and a volatile cache memory, a method for writing specified data to said disk drive comprising the steps of: receiving, by the disk drive from a host controller, a non-volatile cache configuration command, which is used to determine whether the disk drive supports a non-volatile cache function; said disk drive connected to said host controller using an I/O bus; said host controller included within a host computer system; responsive to a receipt of said non-volatile cache configuration command: sending, from said disk drive to said host controller, an indication of whether or not said disk drive supports said non-volatile cache function; and in response to said disk drive supporting said non-volatile cache function: receiving, by said disk drive, a Mode Select command that was sent by said host controller that defines attributes for a non-volatile cache space; in response to receipt of said Mode Select command, said disk drive setting parameters in a new Mode Page that enables non-volatile caching; said parameters persisting over power boundaries until another Mode Select command is received from said host controller that either changes said parameters or disables non-volatile caching; reserving a specified portion of an Outside Diameter (OD) zone of a selected one of said disks for said non-volatile cache space; initially storing said specified data in said volatile cache memory in response to a write command sent to said disk drive; writing said specified data from said volatile cache memory to said non-volatile cache space of said selected disk; and subsequently writing said specified data from said non-volatile cache space to a longer term storage location on a disk of said disk drive.