Method and apparatus using hard disk drive for enhanced non-volatile caching

In a computer configuration comprising a hard disk drive having at least one magnetic disk and a volatile cache memory, apparatus for writing specified data to said disk drive comprising:

• a host controller connected to said disk drive using an I/O bus, said host controller included within a host computer system;
• said disk drive receiving, from said host controller, a non-volatile cache configuration command, which is used to determine whether the disk drive supports a non-volatile cache function;
• responsive to a receipt of said non-volatile cache configuration command:
• said disk drive sending, 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:
• said host controller sending a Mode Select command to said disk drive that defines attributes for a non-volatile cache space;
• in response to receipt of said Mode Select command by said disk drive, 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;
• said host controller configuring said disk drive to reserve a specified portion of an Outside Diameter (OD) zone of a selected one of said disks for said non-volatile cache space;
• disk drive read/write electronics operable to initially store said specified data in said volatile cache memory, in response to a write command sent to said disk drive, and to thereafter write said specified data from said volatile cache memory to said non-volatile cache space of said selected disk;
• and
• a disk drive controller for operating said read/write electronics to write said specified data from said non-volatile cache space to a longer term storage location on a disk of said disk drive.

In a computer configuration comprising a hard disk drive having at least one magnetic disk and a volatile cache memory, a computer program product that is stored in a computer-recordable medium for writing specified data to said disk drive, said computer program product comprising:

• first instructions for 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:
• second instructions for 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:
• third instructions for 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;
• fourth instructions for reserving a specified portion of an Outside Diameter (OD) zone of a selected one of said disks for a non-volatile cache space;
• fifth instructions for initially storing said specified data in said volatile cache memory in response to a write command sent to said disk drive;
• sixth instructions for writing said specified data from said volatile cache memory to said non-volatile cache space of said selected disk;
• and
• seventh instructions for subsequently writing said specified data from said non-volatile cache space to a longer term storage location on a disk of said disk drive.