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Adrian Gerhard Phones & Addresses

  • 2706 Bandel Dr NW, Rochester, MN 55901 (507) 529-5727
  • Juneau, AK
  • 2706 Bandel Dr NW, Rochester, MN 55901

Work

Company: Ibm Position: Engineer

Education

Degree: Bachelor's degree or higher

Skills

Debugging • Perl • Firmware • Storage • Embedded Systems • Device Drivers • Unix • Software Engineering • Software Development • Embedded Software • System Architecture • Scsi • Distributed Systems • Operating Systems • Performance Tuning • Shell Scripting

Industries

Computer Hardware

Resumes

Resumes

Adrian Gerhard Photo 1

Engineer

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Location:
Rochester, MN
Industry:
Computer Hardware
Work:
IBM
Engineer
Skills:
Debugging
Perl
Firmware
Storage
Embedded Systems
Device Drivers
Unix
Software Engineering
Software Development
Embedded Software
System Architecture
Scsi
Distributed Systems
Operating Systems
Performance Tuning
Shell Scripting

Publications

Us Patents

Method And System For Improved Buffer Utilization For Disk Array Parity Updates

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US Patent:
7290199, Oct 30, 2007
Filed:
Nov 19, 2004
Appl. No.:
10/994086
Inventors:
Carl Edward Forhan - Rochester MN, US
Robert Edward Galbraith - Rochester MN, US
Adrian Cuenin Gerhard - Rochester MN, US
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G11C 29/00
US Classification:
714770, 711114, 719325
Abstract:
During a parity update of a parity stripe in a disk array, constant values used in finite field arithmetic are algebraically combined in order to reduce the number of buffers and steps needed to update multiple parity values when a change in data occurs. In one implementation, for example, the contents of a buffer that stores the product of a delta value associated with the change in data and a first constant, which is used to update a first parity value, are multiplied by a value representative of the ratio of a second constant, which is used to update a second parity value, and the first constant.

Method And System For Recovering From Abnormal Interruption Of A Parity Update Operation In A Disk Array System

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US Patent:
7392428, Jun 24, 2008
Filed:
Nov 19, 2004
Appl. No.:
10/994097
Inventors:
Carl Edward Forhan - Rochester MN, US
Robert Edward Galbraith - Rochester MN, US
Adrian Cuenin Gerhard - Rochester MN, US
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G06F 11/00
US Classification:
714 15, 714 6, 714 19
Abstract:
Data associated with the state of a parity update operation in a disk array system such as a RAID-6 system is stored during performance of the operation so that, in the event the operation is interrupted, recovery may be initiated using the stored data. The stored data may include a state indicator that is indicative of the status of the parity update operation, and snapshot data (e. g. , a delta value indicative of a difference between new and old data) captured during the parity update operation.

Method And System For Enhanced Error Identification With Disk Array Parity Checking

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US Patent:
7392458, Jun 24, 2008
Filed:
Nov 19, 2004
Appl. No.:
10/994088
Inventors:
Carl Edward Forhan - Rochester MN, US
Robert Edward Galbraith - Rochester MN, US
Adrian Cuenin Gerhard - Rochester MN, US
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
H03M 13/00
US Classification:
714770, 711114, 719325
Abstract:
When parity checking in a disk array such as a RAID-6 system determines data and parity information is unsynchronized, additional calculations are performed to determine whether the error may be attributed to faulty data on a disk drive or to a more systemic problem such as a faulty controller. In particular, for each particular error detected, the parity generating information is analyzed to determine if each error involves a common disk index. If so, the data can be corrected on that disk; if not other corrective procedures are implemented.

Recovering From Abnormal Interruption Of A Parity Update Operation In A Disk Array System

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US Patent:
7487394, Feb 3, 2009
Filed:
Apr 21, 2008
Appl. No.:
12/106856
Inventors:
Carl Edward Forhan - Rochester MN, US
Robert Edward Galbraith - Rochester MN, US
Adrian Cuenin Gerhard - Rochester MN, US
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G06F 11/00
US Classification:
714 15, 714 6, 714 19
Abstract:
Data associated with the state of a parity update operation in a disk array system such as a RAID-6 system is stored during performance of the operation so that, in the event the operation is interrupted, recovery may be initiated using the stored data. The stored data may include a state indicator that is indicative of the status of the parity update operation, and snapshot data (e. g. , a delta value indicative of a difference between new and old data) captured during the parity update operation.

Method And System For Increasing Parallelism Of Disk Accesses When Restoring Data In A Disk Array System

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US Patent:
7669107, Feb 23, 2010
Filed:
Oct 24, 2007
Appl. No.:
11/923280
Inventors:
Carl Edward Forhan - Rochester MN, US
Robert Edward Galbraith - Rochester MN, US
Adrian Cuenin Gerhard - Rochester MN, US
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G11C 29/00
US Classification:
714763, 714768, 714770
Abstract:
In a disk array environment such as a Redundant Array of Independent Disks-6 (RAID-6) environment, the overall performance overhead associated with exposed mode operations such as resynchronization, rebuild and exposed mode read operations is reduced through increased parallelism. By selecting only subsets of the possible disks required to solve a parity stripe equation for a particular parity stripe, accesses to one or more disks in a disk array may be omitted, thus freeing the omitted disks to perform other disk accesses. In addition, disk accesses associated with different parity stripes may be overlapped such that the retrieval of data necessary for restoring data for one parity stripe is performed concurrently with the storage of restored data for another parity stripe.

Enhanced Error Identification With Disk Array Parity Checking

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US Patent:
7779335, Aug 17, 2010
Filed:
May 23, 2008
Appl. No.:
12/126503
Inventors:
Carl Edward Forhan - Rochester MN, US
Robert Edward Galbraith - Rochester MN, US
Adrian Cuenin Gerhard - Rochester MN, US
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G11C 29/00
US Classification:
714770, 711114, 719325
Abstract:
When parity checking in a disk array such as a RAID-6 system determines data and parity information is unsynchronized, additional calculations are performed to determine whether the error may be attributed to faulty data on a disk drive or to a more systemic problem such as a faulty controller. In particular, for each particular error detected, the parity generating information is analyzed to determine if each error involves a common disk index. If so, the data can be corrected on that disk; if not other corrective procedures are implemented.

Maintaining Write Cache And Parity Update Footprint Coherency In Multiple Storage Adaptor Configuration

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US Patent:
7925837, Apr 12, 2011
Filed:
Mar 4, 2008
Appl. No.:
12/041807
Inventors:
Joseph Roger Edwards - Rochester MN, US
Robert Edward Galbraith - Rochester MN, US
Adrian Cuenin Gerhard - Rochester MN, US
Timothy James Larson - LaCrosse WI, US
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G06F 13/14
US Classification:
711141
Abstract:
A method, computer program product and computer system for maintaining write cache and parity update footprint coherency in a multiple storage adaptor configuration for storage adaptors in a storage subsystem, which includes providing atomic updating of the storage adaptors and the attached disk drives, enabling runtime addition and runtime subtraction of a storage adaptor in the multiple storage adaptor configuration, and maintaining write cache and parity update footprint coherency using atomic updating, runtime addition and runtime subtraction of a storage adaptor.

Dynamic Optimization Of Device Limits And Thresholds In A Write Cache

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US Patent:
7979655, Jul 12, 2011
Filed:
Mar 4, 2008
Appl. No.:
12/041800
Inventors:
Joseph Roger Edwards - Rochester MN, US
Robert Edward Galbraith - Rochester MN, US
Adrian Cuenin Gerhard - Rochester MN, US
Timothy James Larson - LaCrosse WI, US
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G06F 13/00
US Classification:
711162
Abstract:
A method, computer program product and system for dynamically optimizing the limit and the thresholds of a write cache for a storage adapter connected to storage devices, includes measuring continually an overall locality of data in the write cache for the storage devices, calculating the limit of the write cache dynamically for each storage device using the overall locality and a device-related information, and calculating the threshold of the write cache dynamically for each storage device by combining a fair amount and a device-related additional amount.
Adrian C Gerhard from Rochester, MN, age ~47 Get Report