Alan P Rowe, 451060 N Hill Ave, Pasadena, CA 91104

6496942, Dec 17, 2002

Sep 8, 2000

09/657388

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

Network Appliance, Inc. - Sunnyvale CA

G06F 1100

714 4

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.

6829720, Dec 7, 2004

Dec 16, 2002

10/321832

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

Network Appliance, Inc. - Sunnyvale CA

G06F 1100

714 4

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.

7111194, Sep 19, 2006

Mar 21, 2003

10/394854

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

Network Appliance, Inc. - Sunnyvale CA

G06F 11/08
G06F 12/16

714 7, 707202, 707203, 711162

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.

7296068, Nov 13, 2007

Dec 21, 2001

10/027020

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

Network Appliance, Inc. - Sunnyvale CA

G06F 15/173

709223, 711202, 711154, 711156

A system and method for transferring ownership of a volume in a networked storage environment. The method first moves the disks that comprise the volume being transferred from a source-owned state to an un-owned state. Next the disks are moved to a destination-owned state. Each step of the transfer process completes on all disks before the next step begins to ensure consistency and disks that have conflicting owners. Alternate embodiments include logging by the source and destination nodes to permit a resumption of the transfer if one node becomes inactive during the transfer.

7392425, Jun 24, 2008

Jul 12, 2006

11/485544

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

Network Appliance, Inc. - Sunnyvale CA

G06F 12/16
G06F 11/08

714 7, 711162, 707202

A data storage system has two computers. Each computer is assigned to a set of data. Two copies of each set of data are maintained. A first copy is stored on a first set of disks and a second copy is stored on a second set of disks. Each time that a data is written by a computer, a label is written to each set of disks, the label having fields for a status of each computer, a first ordinal which is increased each time that a new data is written, and a time stamp giving a time at which the last write was performed. After failure of a computer, a processor determines, in response to reading the labels of the first set of disks and the second set of disks, the most up to date copy of the data assigned to the failed computer.

7788361, Aug 31, 2010

Oct 4, 2007

11/867130

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

NetApp, Inc. - Sunnyvale CA

G06F 15/173

709223, 709226, 711154, 711156

In a method for operating a data storage system, a request is issued that an ownership attribute of a logical arrangement of storage space associated with a first storage system be associated with a second storage system. In response to the request, the ownership attribute is changed to a state of unowned. In response to the request, and in response to the state of unowned, the ownership attribute of the logical arrangement of storage space is changed to a new set of attributes associated with the second storage system to change ownership of the logical arrangement of storage space from the first storage system to the second storage system.

8060776, Nov 15, 2011

Jun 19, 2008

12/142076

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

NetApp, Inc. - Sunnyvale CA

G06F 12/16
G06F 11/08

714 623, 711162

A data storage system has two computers. Each computer is assigned to a set of data. Two copies of each set of data are maintained. A first copy is stored on a first set of disks and a second copy is stored on a second set of disks. Each time that a data is written by a computer, a label is written to each set of disks, the label having fields for a status of each computer, a first ordinal which is increased each time that a new data is written, and a time stamp giving a time at which the last write was performed. After failure of a computer, a processor determines, in response to reading the labels of the first set of disks and the second set of disks, the most up to date copy of the data assigned to the failed computer.

5577261, Nov 19, 1996

Jan 23, 1995

8/377386

Venkatesh Harinarayan - Menlo Park CA
Srinivasa D. Murthy - San Jose CA
Alan L. Rowe - San Jose CA

Tandem Computers Incorporated - Cupertino CA

G06F 1314

395800

An apparatus and method, using an inter-processor lock to control access to inter-process relationship data structures in the memory of each processor in a multiprocessor system. The apparatus and method insure that each inter-process relationship is modified in the same sequence on each processor. The apparatus and method also insure that an inter-process relationship is maintained in a consistent state in the face of failure of any of the processors.