David M Wolfe

US Patent:

7085909, Aug 1, 2006

Filed:

Apr 29, 2003

Appl. No.:

10/427403

Inventors:

Rajagopal Ananthanarayanan - Milpitas CA, US
Ralph A. Becker-Szendy - Los Gatos CA, US
Robert M. Rees - Los Gatos CA, US
Randal C. Burns - Washington DC, US
Darrell D. E. Long - Soquel CA, US
David M. Wolfe - Portland OR, US
Jason C. Young - Portland OR, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 12/00

US Classification:

711202, 711162, 711206

Abstract:

Various copy-on-write implementations for a computing environment are presented. One copy-on-write implementation includes employing a read mapping table to perform a first virtual block to physical block mapping for use in reading a block of data of a file to be copy-on-written from physical storage for modification; and employing a different, write mapping table to perform a second virtual block to physical block mapping for use in writing a modified block of the file data to physical storage, wherein copy-on-write of the block of data is achieved using a single write operation. In another implementation, a distributed copy-on-write of a file for a client server environment is presented. This distributed copy-on-write includes performing, by a first client, copy-on-write of at least one block of data of the file to be copy-on-written, and performing, by a second client, copy-on-write of at least one other block of data of the file, wherein multiple clients perform the copy-on-write of the file.

US Patent:

7139781, Nov 21, 2006

Filed:

Apr 29, 2003

Appl. No.:

10/427391

Inventors:

Jason C. Young - Portland OR, US
Rajagopal Ananthanarayanan - Milpitas CA, US
Randal C. Burns - Washington DC, US
Darrell D. E. Long - Soquel CA, US
Robert M. Rees - Los Gatos CA, US
Ralph A. Becker-Szendy - Los Gatos CA, US
James J. Seeger - Portland OR, US
David M. Wolfe - Portland OR, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 12/00
G06F 17/30

US Classification:

707204, 707202, 707203

Abstract:

A system and method for managing logical versions of a filesystem made through a near-instantaneous copy process is provided. Each logical version of the filesystem, including the primary version, is assigned a unique epoch number or other identifying value, and each filesystem object is assigned two epoch numbers that define the space of logical versions for which the object exists. A list of all valid epoch numbers are maintained in a version table. The near-instantaneous creation of a logical version of the filesystem requires inserting a unique epoch number entry in the version table () and the next epoch number to the new logical version. An original state of the system is preserved through the use of a copy-on-write procedure for filesystem objects that are reference by that logical filesystem version (). Accordingly, filesystem versions are maintained and original states of previous states of the logical filesystem versions are preserved.

US Patent:

7523204, Apr 21, 2009

Filed:

Jun 1, 2004

Appl. No.:

10/859407

Inventors:

Austin Franky Manuel D'Costa - Beaverton OR, US
James John Seeger - Portland OR, US
David Macnaughton Wolfe - Portland OR, US
David Daniel Zimmermann - Portland OR, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 15/16

US Classification:

709226, 709206, 709223, 709208

Abstract:

A process for quiescing a master (master) and a plurality of subordinate computer systems (subordinates) in a cluster. An original or a pending state may be entered that is a quiesce or an online state. The master instructs the subordinates the quiesce or online state be made the pending state. The subordinates prepare to change accordingly, determine whether successful, and vote to commit or abort. Based on whether all voted to commit, the master instructs the subordinates to either commit or abort. If to commit and the pending state is the quiesce state, an operation is performed in the subordinates. If to commit and the pending state is the online state, the subordinates prepare to resume the original state. The subordinates change from the original to the pending state. Otherwise, if to abort, the subordinates prepare to remain in the original state and reset the pending to the original state.

US Patent:

8166094, Apr 24, 2012

Filed:

Dec 3, 2008

Appl. No.:

12/327133

Inventors:

Austin F. M. D'Costa - Beaverton OR, US
James J. Seeger - Portland OR, US
David M. Wolfe - Portland OR, US
David D. Zimmerman - Portland OR, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 15/16

US Classification:

709201, 709223, 707201, 707202, 707 1, 707999, 707782, 711114, 705 12, 705305, 705802, 705647, 714 6, 714 42, 714 48

Abstract:

A process for quiescing a master and a plurality of subordinate computer systems in a cluster. An original or a pending state may be entered that is a quiesce or an online state. The master instructs the subordinates the quiesce or online state be made the pending state. The subordinates prepare to change accordingly, determine whether successful, and vote to commit or abort. Based on whether all voted to commit, the master instructs the subordinates to either commit or abort. If to commit and the pending state is the quiesce state, an operation is performed in the subordinates. If to commit and the pending state is the online state, the subordinates prepare to resume the original state. The subordinates change from the original to the pending state. Otherwise, if to abort, the subordinates prepare to remain in the original state and reset the pending to the original state.

US Patent:

20040006622, Jan 8, 2004

Filed:

Jul 3, 2002

Appl. No.:

10/189270

Inventors:

Don Burkes - Meridian ID, US
David Kaminsky - Chapel Hill NC, US
Soumitra Sarkar - Cary NC, US
David Wolfe - Portland OR, US

International Classification:

G06F015/173

US Classification:

709/225000, 709/227000

Abstract:

A method, system, and computer program product for facilitating data transfers from a source node group to a target node group. In one embodiment of the invention, a source node selection request is sent to the source node group. The node selection request includes a data transfer session identifier. A source master node belonging to the source node group is configured to route the node selection request to a sending node using a predefined source node selection policy. A target node selection request is sent from the data sending node to the target node group. A target master node belonging to the target node group is configured to route the request to a receiving node using a predefined target node selection policy. The selection policies may include choosing the least loaded node in the data receiving node group.