Netapp, Inc.

Network Appliance, Inc.

Netwrok Appliance, Inc.

Raymond C Chen

Kayuri Hasmukh Patel

John K Edwards

Stephen Lee Manley

Vijayan Rajan

Andy Kahn

Douglas Joseph Santry

Blake H Lewis

Edward Ramon Zayas

Rajesh Sundaram

Srinivasan Viswanathan

Naveen Bali

Paul Christopher Eastham

David Noveck

Sreelatha Sunkara Reddy

Alexander D Petruncola

George Cabrera, Iii

A computerized file system has a first software layer for writing data blocks to persistent storage, and a second software layer for receiving requests from a client, and in response to receiving a request passing a command to the first software layer. A current bit map shows data blocks of persistent storage which are allocated to holding data of the file system. A safe copy of the current bit map is maintained. A third copy of the current bit map is passed, at a selected time, to the first software layer to enable the first software layer to write data blocks containing the bit map current at the selected time to the persistent storage, and simultaneously changing the current bit map as maintained in a computer memory while data blocks containing the bit map current at the selected time are written to the persistent storage.

System and method for reallocating blocks in checkpointing bitmap-based file systems

A system and method for improving the efficiency of the transmission of updated blocks generated by logging all the block allocations and deletes as well as CPs and PCPI creation and deletion in a persistent log. The log is scanned during each update cycle (in which changes are transmitted to a destination mirror) by the storage operating system, and only changed blocks that are referenced by the file system as it existed at the end of the update cycle or referenced by PCPIs that existed at the end of the update cycle are actually sent in the transmission. This reduces the number of changes being transmitted.

System and method for supporting asynchronous data replication with very short update intervals

A file which has been changed from a data storage system is restored. If the file was changed from an active file system, a set of twin pointers is created by copying from the latest pointers in the active file system before the file system was changed. A pointer from the twin pointers is compared with a pointer from a snapshot of the active file system. If a pointer from the twin pointers points to a same data block as the pointer from the snapshot, the twin pointer is written into the active file system to restore the file to the active file system. If the pointers do not point to the same data block, a data of the block is copied to a new block in the active file system to restore data changed since the snapshot was taken.

System and method for restoring a single data stream file from a snapshot

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.

System and method for redirecting access to a remote mirrored snapshot

A method for restoring a file which has been deleted from a data storage system is described. A set of twin pointers is created by copying from the latest pointers in the active file system at a time of restoration. A new set of pointers is created. A pointer from the twin pointers is compared with a pointer from a snapshot of the active file system made at a time earlier than the deletion of the file. In response to a pointer from the snapshot pointing to a different data block than the pointer from the twin pointers, writing the snapshot pointer into the new set of pointers. Writing the new set of pointers into the active file system at the time of restoration to restore the file to the active file system.

A data storage system is disclosed. A flag is maintained in metadata pointing to a block of data. A first value of the flag indicates that the block of data is stored in a user accessible file. A second value of the flag indicates that the block of data is stored in a protected file. The flag pointing to the requested data block is checked upon receipt of a data access request. When the flag has the first value the data access request is permitted. When the flag has the second value, an access control list is checked, and if the requesting client is listed in the access control list permitting the data access request, and if the requesting client is not listed in the access control list denying the data access request.

Metadirectory namespace and method for use of the same

A method and apparatus are disclosed for restoring a virtual disk (vdisk) in a data storage system as the vdisk was at an earlier time. Pointers are maintained to point to data represented by the vdisk. The pointers are saved to persistent storage at the earlier time. The data at the earlier time is maintained on the data storage device. A pointer pointing to data represented by the vdisk at a later time is compared with the pointers saved at the earlier time. If the pointer from the later time matches the pointer saved at the earlier time, keeping the pointer from the later time in the active file system. If the pointer from the later time does not match the pointers saved at the earlier time, copying a set of pointers associated with the pointer saved at the earlier time to the active file system.

System and method for restoring a virtual disk from a snapshot

The present invention relates to a system for restoring a file from a snapshot, where a version of the file exists in both an active file system and the snapshot. A twin inode is created in the active file system and comparisons are made between block pointers of the twin inode and the snapshot. If there is a match, the block pointer of the twin inode is moved to the active file system. If there is not a match, a determination is made whether the snapshot block pointer exists in the active file system. If the snapshot block pointer does not exist in the active file system, it is copied to the active file system. If it does exist, then the actual data block pointed to by the snapshot block pointer is copied to the active file system. In this way, a file may be restored without the need to always copy every individual data block or inode from the snapshot.

System and method for restoring and reconciling a single file from an active file system and a snapshot

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. In this way, there is no overhead added to the filer's storage operating system for generating and validating external file handles configured in accordance with stateful file-system protocols.

Efficient, robust file handle invalidation

A method for restoring a virtual disk (vdisk) in an active file system to an earlier time is described. Pointers pointing to data represented by the virtual disk are maintained. The pointers are saved to persistent storage at the earlier time. A pointer at a later time is compared with the pointers saved at the earlier time. If the pointer from the later time matches the pointer saved at the earlier time, the pointer from the later time is kept in the active file system. If the pointer from the later time does not match the pointers saved at the earlier time, a set of pointers associated with the pointer saved at the earlier time is copied to the active file system.

A system and method for conforming a metadata file associated with qtree of a storage system to a version used by a file system kernel of the storage system, where the version indicates a format of the metadata file. The metadata file stores state information with respect to each qtree, and may be located outside of the qtree structure. Major and minor versions are compared with latest known major and minor versions associated with the file system kernel. In response to such comparisons, the metadata file may be updated to a newer version, rolled back to an older version, and/or the system may enter a corrective state where further operations are performed.

System and method for storage of snapshot metadata in a remote file

A metadirectory namespace is provided for storing files and directories 'hidden' from one or more user-accessible namespaces. The metadirectory namespace is a separate, parallel namespace that coexists with other user-accessible namespaces in a storage operating system. Files and directories may be identified as being stored in a metadirectory based on their location or based on their associated flags. The metadirectory namespace may be selectively exported only to clients, users and applications given special file access permissions.

Growing community of inventors

Campbell, CA, United States of America

Raymond C Chen