Alan D Rowe

US Patent:

6496942, Dec 17, 2002

Filed:

Sep 8, 2000

Appl. No.:

09/657388

Inventors:

Scott Schoenthal - San Ramon CA
Alan Rowe - San Jose CA
Steven R. Kleiman - Los Altos CA

Assignee:

Network Appliance, Inc. - Sunnyvale CA

International Classification:

G06F 1100

US Classification:

714 4

Abstract:

The invention provides a storage system, and a method for operating a storage system, that provides for relatively rapid and reliable takeover among a plurality of independent file servers. Each file server maintains a reliable communication path to the others. Each file server maintains its own state in reliable memory. Each file server regularly confirms the state of the other file servers. Each file server labels messages on the redundant communication paths, so as to allow other file servers to combine the redundant communication paths into a single ordered stream of messages. Each file server maintains its own state in its persistent memory and compares that state with the ordered stream of messages, so as to determine whether other file servers have progressed beyond the file servers own last known state. Each file server uses the shared resources (such as magnetic disks) themselves as part of the redundant communication paths, so as to prevent mutual attempts at takeover of resources when each file server believes the other to have failed. Each file server provides a status report to the others when recovering from an error, so as to prevent the possibility of multiple file servers each repeatedly failing and attempting to seize the resources of the others.

US Patent:

6728922, Apr 27, 2004

Filed:

Aug 18, 2000

Appl. No.:

09/642062

Inventors:

Rajesh Sundaram - Mountain View CA
Alan Rowe - San Jose CA
Steven R. Kleiman - Los Altos CA
John K. Edwards - Sunnyvale CA

Assignee:

Network Appliance, Inc. - Sunnyvale CA

International Classification:

G11C 2900

US Classification:

714769, 714763, 714770

Abstract:

A data storage system, such as RAID, upgraded dynamically including multiple stages, providing error checking data without taking the system off-line. Checksums are computed from the data and placed in block of the same disk. The combination of parity bits across the parity disk, the remaining uncorrupted data in the data disks, and checksums within each disk includes sufficient information to enable restoration of corrupt data. The system is upgraded by reserving permanent checksum blocks, writing the checksums to a volume block number, and placing the checksums in permanently reserved checksum block locations after first moving data already there to unreserved blocks.

US Patent:

6829720, Dec 7, 2004

Filed:

Dec 16, 2002

Appl. No.:

10/321832

Inventors:

Scott Schoenthal - San Ramon CA
Alan Rowe - San Jose CA
Steven R. Kleiman - Los Altos CA

Assignee:

Network Appliance, Inc. - Sunnyvale CA

International Classification:

G06F 1100

US Classification:

714 4

Abstract:

The invention provides a storage system, and a method for operating a storage system, that provides for relatively rapid and reliable takeover among a plurality of independent file servers. Each file server maintains a reliable communication path to the others. Each file server maintains its own state in reliable memory. Each file server regularly confirms the state of the other file servers. Each file server labels messages on the redundant communication paths, so as to allow other file servers to combine the redundant communication paths into a single ordered stream of messages. Each file server maintains its own state in its persistent memory and compares that state with the ordered stream of messages, so as to determine whether other file servers have progressed beyond the file servers own last known state. Each file server uses the shared resources (such as magnetic disks) themselves as part of the redundant communication paths, so as to prevent mutual attempts at takeover of resources when each file server believes the other to have failed. Each file server provides a status report to the others when recovering from an error, so as to prevent the possibility of multiple file servers each repeatedly failing and attempting to seize the resources of the others.

US Patent:

6965989, Nov 15, 2005

Filed:

Aug 14, 2001

Appl. No.:

09/929527

Inventors:

Stephen H. Strange - Mountain View CA, US
Alan L. Rowe - San Jose CA, US
R. Guy Lauterbach - Penn Valley CA, US

Assignee:

Network Appliance, Inc. - Sunnyvale CA

International Classification:

G06F001/24

US Classification:

713 1, 713 2, 709220, 709222

Abstract:

A system and method for fast (“warm”) reboot of a file server is provided, which skips certain conventional boot processes when circumstances warrant, in order to reduce server downtime. In particular, time is saved by avoiding a full shutdown of the processor and memory, and by causing the firmware to refrain from a full clearance of the file server memory. Instead, the firmware accesses a retained copy of the storage operating system kernel from a reserved location in the file server memory so that an operative version of the kernel is reestablished at the appropriate address space in memory without requiring a time-consuming read of the kernel image from disk. In addition, other “normal” (cold) reboot operations such as full memory tests, hardware checks and memory zeroing are avoided as appropriate—saving further time in the overall reboot process, while still attaining the desired reinitialization of key applications and functions.

US Patent:

7003714, Feb 21, 2006

Filed:

Apr 26, 2004

Appl. No.:

10/832100

Inventors:

Rajesh Sundaram - Mountain View CA, US
Alan Rowe - San Jose CA, US
Steven R. Kleiman - Los Altos CA, US
John K. Edwards - Sunnyvale CA, US

Assignee:

Network Appliance, Inc. - Sunnyvale CA

International Classification:

G11C 29/00

US Classification:

714769, 714766

Abstract:

A data storage system, such as RAID, upgraded dynamically including multiple stages, providing error checking data without taking the system off-line. Checksums are computed from the data and placed in block of the same disk. The combination of parity bits across the parity disk, the remaining uncorrupted data in the data disks, and checksums within each disk includes sufficient information to enable restoration of corrupt data. The system is upgraded by reserving permanent checksum blocks, writing the checksums to a volume block number, and placing the checksums in permanently reserved checksum block locations after first moving data already there to unreserved blocks.

US Patent:

7111194, Sep 19, 2006

Filed:

Mar 21, 2003

Appl. No.:

10/394854

Inventors:

Scott Schoenthal - San Ramon CA, US
Steven H. Rodrigues - Mountain View CA, US
Alan L. Rowe - San Jose CA, US
Joydeep sen Sarma - Mountainview CA, US
Susan M. Coatney - Cupertino CA, US

Assignee:

Network Appliance, Inc. - Sunnyvale CA

International Classification:

G06F 11/08
G06F 12/16

US Classification:

714 7, 707202, 707203, 711162

Abstract:

A technique includes a set of procedures utilized during the transfer of service of a failed storage system to a surviving storage system of a cluster failover (CFO) configuration during a system outage, such as a disaster scenario. The procedures are executed by a RAID subsystem of the surviving storage system during disaster takeover, storage healing and node restart operations. The procedures prevent the possibility that clients accessing the storage system will see out-of-date versions of the data either during transfer of service of the system during the disaster scenario or subsequently after the storage system is healed and service on the failed system has been restored.

US Patent:

7146522, Dec 5, 2006

Filed:

Dec 21, 2001

Appl. No.:

10/027013

Inventors:

Alan L. Rowe - San Jose CA, US
Richard O. Larson - Cupertino CA, US
Susan M. Coatney - Cupertino CA, US
Joydeep sen Sarma - Redwood City CA, US
Samuel M. Cramer - Sunnyvale CA, US

Assignee:

Network Appliance, Inc. - Sunnyvale CA

International Classification:

G06F 11/00

US Classification:

714 6, 714 7, 714 42, 711158, 711162, 369 5317, 369 4713

Abstract:

A system and method for a file server to allocate spare disks in a network storage system. The method determines the available spare disks and first selects those disks that satisfy one or more required rules. The method sorts the spare disks by a set of ordered policies to determine a highest-ranked disk that is then selected as the spare to be utilized. If multiple disks are equally ranked, one of the equally ranked disks is randomly chosen to be the spare disk allocated.

US Patent:

7231489, Jun 12, 2007

Filed:

Mar 3, 2003

Appl. No.:

10/378400

Inventors:

Richard O. Larson - Cupertino CA, US
Alan L. Rowe - San Jose CA, US
Joydeep sen Sarma - Mountainview CA, US

Assignee:

Network Appliance, Inc. - Sunnyvale CA

International Classification:

G06F 12/00
G06F 13/00
G06F 13/28

US Classification:

711111, 711114, 711152, 711163

Abstract:

A system and method for an improved mailbox mechanism to contain coordinating information for computers in a cluster environment is provided. The system and method creates two copies of a master mailbox record stored in a set and predetermined location on disks associated with the cluster. A subset of the disks is designated as lock disks, which must contain the most up-to-date coordinating information.