Abstract: Embodiments of the present invention allow multiple checkpoints to be taken so that multiple versions of the filesystem, including a working version and at least two checkpoint versions, can be maintained over time. Specifically, at least three “superblock” root structures are used to manage multiple instantiations of the filesystem. The superblocks are preferably stored in fixed locations within the storage system for easy access, although they may alternatively be stored in other ways. The number of superblocks may be fixed or variable.

Abstract: Apparatus for managing a plurality of root nodes may include a file server coupled to a storage device, wherein a first root node is operable to identify a previous version of an object of a file system and to relate to a plurality of data blocks forming a portion of the object, a second root node is operable to identify a current version of the object and to relate to a data block of the plurality of data blocks and a new data block of the object, and the storage device is operable to store the plurality of data blocks and the new data block.

Abstract: Apparatus includes a file server node having (i) a first interface operable to communicate with a network and receiving a network request via network, (ii) a non-volatile memory operable to temporarily store a request related to the network request received by the first interface, (iii) a second interface operable to be coupled to the storage device for storing the request, and (iv) a non-volatile memory processing module, coupled to the first interface, the non-volatile memory and the second interface, and operable to be coupled to another file server node, so that the request can be sent to the non-volatile memory, the second interface and the another file server node after the non-volatile memory processing module receives the file system request.

Abstract: A distributed file system and method distributes file system objects across multiple self-contained volumes, where each volume is owned by a unique file system node. Logical links are used to reference a file system object between volumes. Each file system node includes a relocation directory in which is maintained hard links to locally-stored file system objects that are referenced from another file system node using logical links. Various file system operations that involve multiple volumes are performed without having to place a write lock on more than one volume at a time. Various caching schemes allow the various file system nodes to cache file system object data and metadata.

Abstract: Apparatus includes a file server node having (i) a first interface operable to communicate with a network and receiving a network request via network, (ii) a non-volatile memory operable to temporarily store a request related to the network request received by the first interface, (iii) a second interface operable to be coupled to the storage device for storing the request, and (iv) a non-volatile memory processing module, coupled to the first interface, the non-volatile memory and the second interface, and operable to be coupled to another file server node, so that the request can be sent to the non-volatile memory, the second interface and the another file server node after the non-volatile memory processing module receives the file system request.

Abstract: Apparatus for managing a plurality of root nodes may include a file server coupled to a storage device, wherein a first root node is operable to identify a previous version of an object of a file system and to relate to a plurality of data blocks forming a portion of the object, a second root node is operable to identify a current version of the object and to relate to a data block of the plurality of data blocks and a new data block of the object, and the storage device is operable to store the plurality of data blocks and the new data block.

Abstract: Apparatus for managing plural versions of a root node for an object of a file system manages an update data of a first version of the plural versions of the root node in a status in which (i) data of a second version of the plural versions of the root node is written from the second storage of the file server to the first storage and (ii) a new checkpoint, capable of being used when the object of the file system is recovered, is taken. The apparatus also manages an update data of the second version of the plural versions of the root node in another status in which (iii) data of the first version of the plural versions of the root node is written from the second storage of the file server to the first storage and (iv) a next new checkpoint is taken.

Abstract: A hardware-based file system includes multiple linked sub-modules that perform functions ancillary to client data handling. Each sub-module is associated with a metadata cache. A doubly-rooted structure is used to store each file system object at successive checkpoints. Metadata is stored within an object and/or as a separate object. Provisions are made for allocating sparse objects. A delayed write feature is used for writing certain objects into non-volatile storage. Checkpoints can be retained as read-only versions of the file system. Modifications to the file system are accomplished without affecting the contents of retained checkpoints. The file system can be reverted to a retained checkpoint. Multiple file servers can be interconnected as a cluster, and each file server stores requests from another file server. Interconnections between file servers can be dynamically modified. A distributed locking mechanism is used to control access to file system objects stored by the file servers.

Abstract: A hardware-based file system includes multiple linked sub-modules that perform functions ancillary to client data handling. Each sub-module is associated with a metadata cache. A doubly-rooted structure is used to store each file system object at successive checkpoints. Metadata is stored within an object and/or as a separate object. Provisions are made for allocating sparse objects. A delayed write feature is used for writing certain objects into non-volatile storage. Checkpoints can be retained as read-only versions of the file system. Modifications to the file system are accomplished without affecting the contents of retained checkpoints. The file system can be reverted to a retained checkpoint. Multiple file servers can be interconnected as a cluster, and each file server stores requests from another file server. Interconnections between file servers can be dynamically modified. A distributed locking mechanism is used to control access to file system objects stored by the file servers.

Abstract: A distributed file system and method distributes file system objects across multiple self-contained volumes, where each volume is owned by a unique file system node. Logical links are used to reference a file system object between volumes. Each file system node includes a relocation directory in which is maintained hard links to locally-stored file system objects that are referenced from another file system node using logical links. Various file system operations that involve multiple volumes are performed without having to place a write lock on more than one volume at a time. Various caching schemes allow the various file system nodes to cache file system object data and metadata.

Abstract: A distributed file system and method distributes file system objects across multiple self-contained volumes, where each volume is owned by a unique file system node. Logical links are used to reference a file system object between volumes. Each file system node includes a relocation directory in which is maintained hard links to locally-stored file system objects that are referenced from another file system node using logical links. Various file system operations that involve multiple volumes are performed without having to place a write lock on more than one volume at a time. Various caching schemes allow the various file system nodes to cache file system object data and metadata.

Abstract: A file system adapter card that may be plugged into a host computer system for providing hardware-based file system accesses outside the purview of a host operating system running on the host computer system. The file system adapter card includes a hardware-implemented or hardware-accelerated file service subsystem and a computer bus that permits a host computer system to communicate directly with the file service subsystem for providing file service requests and receiving file service responses. The file service subsystem includes dedicated hardware that operates outside the immediate control of a host operating system, including specialized circuitry for performing at least one major subsystem function.

Abstract: Embodiments of the present invention allow multiple checkpoints to be taken so that multiple versions of the filesystem, including a working version and at least two checkpoint versions, can be maintained over time. Specifically, at least three “superblock” root structures are used to manage multiple instantiations of the filesystem. The superblocks are preferably stored in fixed locations within the storage system for easy access, although they may alternatively be stored in other ways. The number of superblocks may be fixed or variable.

Abstract: A hardware-based file system includes multiple linked sub-modules that perform functions ancillary to client data handling. Each sub-module is associated with a metadata cache. A doubly-rooted structure is used to store each file system object at successive checkpoints. Metadata is stored within an object and/or as a separate object. Provisions are made for allocating sparse objects. A delayed write feature is used for writing certain objects into non-volatile storage. Checkpoints can be retained as read-only versions of the file system. Modifications to the file system are accomplished without affecting the contents of retained checkpoints. The file system can be reverted to a retained checkpoint. Multiple file servers can be interconnected as a cluster, and each file server stores requests from another file server. Interconnections between file servers can be dynamically modified. A distributed locking mechanism is used to control access to file system objects stored by the file servers.