Optimizing execution of i/o requests for a disk drive in a computing system

An apparatus for optimizing execution of Input/Output ('I/O′) requests for a disk drive, the apparatus comprising:

• a computer processor;
• the disk drive coupled with the computer processor;
• a computer readable medium coupled with the computer processor, the computer readable media encoded with computer program instructions capable of,
• receiving an I/O request specifying a plurality of disk blocks of the disk drive for access, each disk block characterized by a disk drive head, a cylinder, and a sector of the disk drive;
• determining a plurality of I/O sub-requests from the I/O request, each I/O sub-request specifying a set of one or more adjacent disk blocks of the plurality of disk blocks along the same cylinder;
• determining a plurality of execution sequences for performing the plurality of I/O sub-requests, wherein each of the plurality of execution sequences indicates a different order to perform the plurality of I/O sub-requests;
• calculating, for each of the plurality of execution sequences, a total estimated execution time for performing the I/O sub-requests according to the execution sequence;
• selecting one of the plurality of execution sequences for performing the I/O sub-requests based, at least in part, on the total estimated execution times for the plurality of execution sequences;
• and
• instructing a disk drive controller to perform the I/O sub-requests according to the selected execution sequence.

A computer program product for optimizing execution of Input/Output ('I/O′) requests for a disk drive, the computer program product comprising:

• a computer readable storage medium having computer usable program code embodied therewith, the computer usable program code comprising a computer usable program code configured to:
• receive an I/O request specifying a plurality of disk blocks of the disk drive for access, each disk block characterized by a disk drive head, a cylinder, and a sector of the disk drive;
• determine a plurality of I/O sub-requests from the I/O request, each I/O sub-request specifying a set of one or more adjacent disk blocks of the plurality of disk blocks along the same cylinder;
• determine a plurality of execution sequences for performing the plurality of I/O sub-requests, wherein each of the plurality of execution sequences indicates a different order to perform the plurality of I/O sub-requests;
• calculate, for each of the plurality of execution sequences, a total estimated execution time for performing the I/O sub-requests according to the execution sequence;
• select one of the plurality of execution sequences for performing the I/O sub-requests based, at least in part, on the total estimated execution times for the plurality of execution sequences;
• and
• instruct a disk drive controller to perform the I/O sub-requests according to the selected execution sequence.