Resource reservation system in a computer network to support end-to-end quality-of-service constraints

A method of reserving resources in a computer network to support a predetermined Quality-of-Service constraint with respect to a new access request to transmit data between a disk drive and a client computer, the computer network comprising a plurality of interconnected computer devices including a plurality of disk drives, each disk drive comprising a head and a disk, the method comprising the steps of:

• (a) finding at least one disk drive out of the plurality of disk drives that can service the new access request while supporting the Quality-of-Service constraint for the new and existing access requests;
• and
• (b) reserving resources within the at least one disk drive to service the new access request,
• wherein the step of reserving resources comprises the step of limiting movement of the head so as to constrain the head to a predetermined region of the disk.

A computer network comprising:

• (a) a plurality of interconnected computer devices including a plurality of client computers and a plurality of disk drives for storing network data, each disk drive comprising a head and a disk;
• (b) a plurality of interconnected nodes;
• and
• (c) a reservation facility for reserving resources within the disk drives and the nodes to support a predetermined Quality-of-Service constraint with respect to data transmitted between the disk drives and the client computers through the nodes of the computer network,
• wherein the reservation facility limits movement of the head so as to constrain the head to a predetermined region of the disk thereby reserving a resource within the disk drive.

A computer network comprising:

• (a) a plurality of interconnected computer devices including a plurality of disk drives for storing network data, the disk drives each comprising a head and a disk;
• (b) a plurality of interconnected nodes;
• and
• (c) a reservation facility for reserving resources within the disk drives and the nodes to support a predetermined Quality-of-Service constraint with respect to data transmitted between the disk drives through the nodes of the computer network,
• wherein the reservation facility limits movement of the head so as to constrain the head to a predetermined region of the disk, thereby reserving a resource within the node.

A switched fabric computer network comprising:

• (a) a plurality of interconnected nodes for simultaneously transmitting data in multiple dimensions through the computer network, each node comprising:
• switching circuitry comprising more than two bi-directional ports;
• a disk for storing data;
• and
• a head actuated over the disk for writing data to and reading data from the disk;
• (b) a reservation facility for reserving resources associated with reading data from the disk and writing data to the disk to support a predetermined Quality-of-Service constraint with respect to data transmitted between the interconnected nodes and client computers connected to the switched fabric computer network;
• and
• (c) a scheduling facility, responsive to the resources reserved by the reservation facility, for scheduling the transmission of the transmitted data through the interconnected nodes to support the predetermined Quality-of-Service constraint.