Disk array system with controllers that prefetch and buffer ATA disk drive commands

A disk array system, comprising:

• a plurality of ATA (Advanced Technology Attachment) disk drives;
• and
• a plurality of controllers, each of which controls a respective ATA disk drive of the plurality of ATA disk drives;
• wherein each controller includes a command buffer that stores disk drive commands, and issues said disk drive commands therefrom for execution by the respective ATA disk drive;
• and wherein each controller further includes a respective automated circuit that prefetches disk drive commands into its respective command buffer, so that a next disk drive command is available in the respective command buffer to issue therefrom when the respective ATA disk drive finishes executing a current disk drive command.

A method of controlling an ATA disk drive of a disk array system, the method comprising:

• dispatching a first disk drive command to a controller that controls the ATA disk drive, the first disk drive command specifying a first disk operation, wherein the controller is external to the ATA disk drive;
• storing the first disk drive command in a command buffer of the controller;
• issuing the first disk drive command from the command buffer of the controller to the ATA disk drive for execution;
• during execution of the first disk drive command by the ATA disk drive, dispatching a second disk drive command to the controller, and storing the second disk drive command within the command buffer of the controller, wherein the second disk drive command specifies a second disk operation;
• and
• when the ATA disk drive finishes executing the first disk drive command, issuing the second disk drive command from the command buffer to the ATA disk drive for execution.