Patent ID: 6134630
Filing Date: 2000-10-17
Classification: G06F

Abstract:
A disk array controller which operatively connects a host computer to an array of disk drives, the host computer including a system memory, the disk array controller comprising:a plurality of disk drive controllers, each disk drive controller connected to and configured to control at least one disk drive of the array;a microcontroller which dispatches controller commands to the disk drive controllers over a first bus to initiate transfers of input/output (I/O) data between the disk drives and the host computer, the microcontroller responsive to I/O requests generated by the host computer; andan automated processor which transfers I/O data between at least the disk drive controllers and the system memory, the automated processor connected to the plurality of disk drive controllers by a packet bus which is separate from the first bus such that transfers of controller commands to the disk drive controllers do not interfere with transfers of I/O data;wherein the disk drive controllers transfer the I/O data to the automated processor in packets over the packet bus, and the automated processor implements a bus arbitration protocol to control accesses by the disk drive controllers to the packet bus,and wherein the bus arbitration protocol guarantees a minimum I/O bandwidth of substantially 1/N of the total I/O bandwidth of the packet bus to each disk drive controller where N is the number of disk drive controllers, said minimum I/O bandwidth being greater than or equal to the sustained data transfer rate of each disk drive of the array, whereby all N disk drives can operate concurrently at the sustained data rate without the formation of a bottleneck.