James Paul Hafner

US Patent:

6345376, Feb 5, 2002

Filed:

Jul 18, 2000

Appl. No.:

09/618414

Inventors:

Charles Edwin Cox - San Jose CA
Myron Dale Flickner - San Jose CA
James Lee Hafner - San Jose CA
Martin Aureliano Hassner - Palo Alto CA
Barry Marshall Trager - Yorktown Heights NY
Shmuel Winograd - Scarsdale NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H03M 1300

US Classification:

714785, 714781

Abstract:

A computationally efficient, machine-implementable method and means for detecting and correcting errors in received codewords on-the-fly within the capacity of a linear cyclic code using ultra-fast error location processing. Each error locator polynomial of degree t over a finite Galois field derived from a codeword syndrome is mapped into a matrix representative of a system of linear simultaneous equations related to the polynomial coefficients. Roots indicative of error locations within the codeword are extracted from the matrix by a modified Gaussian Elimination process for all the roots where t5 and at least one root plus a subset of candidate roots from the finite field for iterative substitution where t 5. Corrected values are separately determined and correction is secured by logically combining the corrected values with the codeword values in error at the error locations represented by the roots.

US Patent:

6438724, Aug 20, 2002

Filed:

Mar 16, 1999

Appl. No.:

09/270069

Inventors:

Charles Edwin Cox - San Jose CA
James Lee Hafner - San Jose CA
Martin Aureliano Hassner - Palo Alto CA
Ralph Koetter - Urbana IL
Arvind Motibhai Patel - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H03M 1315

US Classification:

714758

Abstract:

A method and apparatus for ensuring the integrity of data that can detect errors that remain when the data correction scheme fails to correct at least some of the errors, or has added additional errors. Reed-Solomon check symbols are used for error correction and cyclic redundancy check symbols are used to detect the remaining errors. The roots of the generator polynomials used to generate the Reed-Solomon check symbols and the cyclic redundancy check symbols meet a selected subset of a plurality of conditions. The roots are further selected so that the necessary exponentiation may be performed by a combination of exponentiations by powers of two and multiplications. The Reed-Solomon check symbols are generated based on the data portion of the data block. A deterministically altered data stream is generated based on the data portion of the data block and the cyclic redundancy check symbols are generated based on the deterministically altered data stream. The deterministically altered data stream is generated by performing an operation on a symbol of the data portion based on a position of the symbol within a Reed-Solomon codeword.

US Patent:

6446234, Sep 3, 2002

Filed:

Mar 16, 1999

Appl. No.:

09/269000

Inventors:

Charles Edwin Cox - San Jose CA
James Lee Hafner - San Jose CA
Martin Aureliano Hassner - Palo Alto CA
Ralph Koetter - Urbana IL
Arvind Motibhai Patel - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H03M 1315

US Classification:

714758

Abstract:

A method and apparatus for ensuring the integrity of data that can detect errors that remain when the data correction scheme fails to correct at least some of the errors, or has added additional errors. Reed-Solomon check symbols are used for error correction and cyclic redundancy check symbols are used to detect the remaining errors. The roots of the generator polynomials used to generate the Reed-Solomon check symbols and the cyclic redundancy check symbols meet a selected subset of a plurality of conditions. The roots are further selected so that the necessary exponentiation may be performed by a combination of exponentiations by powers of two and multiplications. The Reed-Solomon check symbols are generated based on the data portion of the data block. A deterministically altered data stream is generated based on the data portion of the data block and the cyclic redundancy check symbols are generated based on the deterministically altered data stream. The deterministically altered data stream is generated by performing an operation on a symbol of the data portion based on a position of the symbol within a Reed-Solomon codeword.

US Patent:

7013205, Mar 14, 2006

Filed:

Nov 22, 2004

Appl. No.:

10/992840

Inventors:

James Lee Hafner - San Jose CA, US
John Anthony Tomlin - Sunnyvale CA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

B60K 6/04
B60L 9/00
B60L 11/00

US Classification:

701 22, 903908, 180 652, 180 656, 180165, 475 1

Abstract:

The present invention provides a system and method relating to the operation of plug-in hybrid electric vehicles powered both by electricity from rechargeable batteries and by consumable fuel powered means, such as an internal combustion engine or a fuel cell. More particularly, the system and method of the claimed invention enable optimization of the energy cost associated with the operation of such plug-in hybrid electric vehicles, especially when the cost of recharging batteries from external electric power sources may be less than the cost of recharging batteries from the onboard consumable fuel powered means. To this end, the invention enables maximization of the use of electricity from external electric power sources and minimization of the use of electricity produced by the plug-in hybrid electric vehicle's onboard consumable fuel powered means, when the cost of recharging batteries from external electric power sources is less than the cost of recharging batteries from the onboard consumable fuel powered means.

US Patent:

7159150, Jan 2, 2007

Filed:

Dec 31, 2002

Appl. No.:

10/335284

Inventors:

James L. Hafner - San Jose CA, US
Marc T. Roskow - Los Gatos CA, US
Omer A. Zaki - San Jose CA, US
Dulce B. Ponceleon - Palo Alto CA, US
Richard F. Freitas - San Martin CA, US
Garth R. Goodson - Pittsburgh PA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 11/00

US Classification:

714 43, 714 4, 714 6, 714 9

Abstract:

A collective storage system and method for restoring data in the system after a failure in the system. The system includes multiple storage nodes that are interconnected by a network and store data as extents. There are also a set of Data Service (DS) agents for managing the extents, a set of Metadata Service (MDS) agents for managing metadata relating to the nodes and the extents, and a Cluster Manager (CM) agent in each node. After a node failure is detected by one of the CM agents, the agents responsible for coordinating the data restoring are notified of the failure. The agents generate a plan to restore the data extents affected by the failure, and then collectively restoring the affected extents based on the generated plan. The coordinating agents might be the MDS agents or DS agents. The failure might be a node failure or a disk failure.

US Patent:

7519629, Apr 14, 2009

Filed:

Sep 30, 2004

Appl. No.:

10/956466

Inventors:

James Lee Hafner - San Jose CA, US
Jeffrey R. Hartline - Ithaca NY, US
Tapas Kanungo - San Jose CA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 17/00

US Classification:

707202, 708531, 711114, 714 6, 714800, 707203, 707204

Abstract:

A fault-tolerant system for storage arrays has constraints on the number of data from which each redundancy value is computed. The fault-tolerant system has embodiments that are supported on small array sizes to arbitrarily large array sizes, and can tolerate a large number T of failures. Certain embodiments can tolerate many instances of more than T failures. The fault-tolerant system has efficient XOR-based encoding, recovery, and updating algorithms and has simple redundancy formulas. The fault-tolerant system has improved IO seek costs for certain multiple-element sequential host updates.

US Patent:

7536588, May 19, 2009

Filed:

Feb 8, 2006

Appl. No.:

11/350247

Inventors:

James Lee Hafner - San Jose CA, US
Krishnakumar Surugucchi - Fremont CA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 11/00

US Classification:

714 6, 714 5, 714 20

Abstract:

A bladed storage servicing system comprising a RAID layout facilitates the removal of one or more functional storage devices in a tray of the bladed storage subsystem in order to service a failed storage device. Upon removal of the tray from the bladed storage subsystem, the system designates the functional storage devices on the tray as temporarily removed. The system logs writes to the removed functional storage devices so that the functional storage devices can be returned to consistency when replaced in the bladed storage subsystem. The system manages reads to the removed functional storage devices through reconstruction from active storage devices in the bladed storage subsystem. Upon reinsertion of the tray in the bladed storage subsystem, the system verifies the identities of the functional storage devices and resynchronizes the functional storage devices to ensure data consistency.

US Patent:

7752489, Jul 6, 2010

Filed:

May 10, 2007

Appl. No.:

11/747188

Inventors:

Veera W. Deenadhayalan - San Jose CA, US
James L. Hafner - San Jose CA, US
James C. Wyllie - Monte Sereno CA, US
Wendy A Belluomini - San Jose CA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 11/00

US Classification:

714 6

Abstract:

Data validation systems and methods are provided. Data is recorded in N data chunks on one or more storage mediums. A first validation chunk independently associated with said N data chunks comprises first validation information for verifying accuracy of data recorded in said N data chunks. The first validation chunk is associated with a first validation appendix comprising second validation information, wherein the first validation appendix is stored on a first storage medium independent of said one or more storage mediums.