Raymond C Chen, 32Union City, CA

6799284, Sep 28, 2004

Feb 28, 2001

09/797007

Kayuri Patel - Cupertino CA
Raymond Chen - Campbell CA
Rajesh Sundaram - Mountain View CA
Srinivasan Viswanathan - Fremont CA
Andy Kahn - San Francisco CA

Network Appliance, Inc. - Sunnyvale CA

G06F 1100

714 6, 711114

The invention provides a method and system for reducing RAID parity computation following a RAID subsystem failure. Ranges of RAID stripes are assigned to bits in a bitmap that is stored on disk. When writes to the RAID are in progress, the bit associated with the range of stripes in the bitmap is set. When a failure occurs during the write process, the bitmap is analyzed on reboot to determine which ranges of stripes where in the process of being written, and the parity data for only those ranges of stripes is recomputed. Efficiency is increased by use of an in-memory write counter that tracks multiple writes to each stripe range. Using the write counter, the bitmap is written to disk only after each cycle of its associated bitmap bit being set to a value of 1 and then returning to zero. The invention may be installed, modified, and removed at will from a RAID array, and this may be accomplished while the system is in operation.

7010553, Mar 7, 2006

Mar 19, 2002

10/100434

Raymond C. Chen - Campbell CA, US
Stephen L. Manley - London, GB

Network Appliance, Inc. - Sunnyvale CA

G06F 17/30

707203

In a system and method for updating a remote replicated destination file system snapshot with changes in a source file system snapshot, users and processes are redirected to a local exported snapshot of the replicated snapshot on the active file system on the destination before beginning the next update of the active file system's replicated snapshot. In this manner, an unstable replicated snapshot is not accessed. Indirection is introduced into inode lookup at the destination as the destination's active file system is being updated. The indirection can be based upon a snapshot ID that conforms to a latest exported snapshot ID.

7043485, May 9, 2006

Mar 19, 2002

10/100945

Stephen L. Manley - London, GB
Raymond C. Chen - Campbell CA, US
John K. Edwards - Sunnyvale CA, US

Network Appliance, Inc. - Sunnyvale CA

G06F 17/30

707100, 707200

In a system and method for updating a remote replicated destination file system snapshot with changes in a source file system snapshot, the snapshot being associated with a qtree (or other sub-organization of the file system volume), a qtree metadata file on the destination in provided. The qtree metadata file resides, in the destination volume, and outside the qtree structure. The metadata file stores state information with respect to each qtree. This metadata file resides at a known location in the destination volume. The metadata file can include a plurality of fixed length records having respective fields for storing various information including qtree-specific information, and can be part of a hidden metadata directory.

7051050, May 23, 2006

Mar 19, 2002

10/100948

Raymond C. Chen - Campbell CA, US
Kayuri Patel - Cupertino CA, US
Andy C. Kahn - San Francisco CA, US
John K. Edwards - Sunnyvale CA, US

Netwrok Appliance, Inc. - Sunnyvale CA

G06F 17/30

707200, 711162

The present invention provides a system and method for restoring a single file from a snapshot without the need to copy every individual block or inode from the snapshot. A file restore process duplicates the inode of a file within the active file system and performs a reconciliation process between the blocks of the twin inode and the snapshot inode. If the file does not exist within the active file system, a new buffer tree is created that points to the data blocks stored in the snapshot.

7072910, Jul 4, 2006

Mar 22, 2002

10/104694

Andy C. Kahn - San Francisco CA, US
Kayuri Patel - Cupertino CA, US
Raymond C. Chen - Campbell CA, US
John K. Edwards - Sunnyvale CA, US

Network Appliance, Inc. - Sunnyvale CA

G06F 17/30

707201, 707204, 707202, 707200, 707100, 707 1

A file folding technique reduces the number of duplicate data blocks of a file consumed on a storage device of a file server configured to generate a persistent image of its active file system at a point in time. According to the file folding technique, if “old” data blocks of the file are over-written with “new” data and that new data is identical to the data of the persistent file image, the old data blocks are “freed” and the file is directed to refer to the persistent image for its data. The invention reduces disk space consumption in a file server configured to generate persistent images of its active file system and, in particular, reduces overall persistent image disk usage.

7076509, Jul 11, 2006

Mar 21, 2003

10/394856

Raymond C. Chen - Campbell CA, US
Kayuri Patel - Cupertino CA, US
Vijayan Rajan - Sunnyvale CA, US

Network Appliance, Inc. - Sunnyvale CA

G06F 17/30

707202, 707 8

The present invention provides a system and method for restoring a vdisk from a snapshot without the need to copy every individual block or inode from the snapshot. A vdisk restore process duplicates the inode of a vdisk within the active file system and performs a reconciliation process between the blocks of the twin inode and the snapshot inode. If the vdisk does not exist within the active file system, a new buffer tree is created that points to the data blocks stored in the snapshot.

7117303, Oct 3, 2006

Mar 14, 2003

10/389451

Edward R. Zayas - Milpitas CA, US
Raymond C. Chen - Campbell CA, US
Blake H. Lewis - Los Altos Hills CA, US

Network Appliance, Inc. - Sunnyvale CA

G06F 12/00

711112, 711114

The present invention provides a technique for efficiently generating and validating external file handles at a storage operating system of a filer. According to one aspect of the technique, the storage operating system associates a unique internal file handle with each file or directory stored in the filer. This unique internal file handle is used to generate a corresponding external file handle. Unlike previous approaches, the internal file handles' representations do not change depending on the location of their corresponding files or directories, e. g. , on-disk or in-core, within the filer, thereby simplifying file management within the filer. According to another aspect of the inventive technique, the filer executes a file-handle validation procedure to determine whether an external file handle received with a file access request has become invalid (or “stale”) as a result of an NVRAM failure in the filer. The file-handle validation procedure enables the filer to efficiently determine the validity of the external file handle without having to perform conventional time-consuming and processing-intensive operations. Advantageously, the inventive technique is preferably only applied to generation and validation of external file handles configured in accordance with a stateless file-system protocol, such as the NFS protocol.

7165079, Jan 16, 2007

Mar 21, 2003

10/393781

Raymond C. Chen - Campbell CA, US
Kayuri Patel - Cupertino CA, US
Vijayan Rajan - Sunnyvale CA, US

Network Appliance, Inc. - Sunnyvale CA

G06F 17/30

707202, 707203, 707204, 711162

The present invention provides a system and method for restoring a single data stream file from a snapshot without the need to copy every individual block or inode from the snapshot. A file restore process duplicates the inode of a file within the active file system and performs a reconciliation process between the blocks of the twin inode and the snapshot inode. If the file does not exist within the active file system, a new buffer tree is created that points to the data blocks stored in the snapshot.