Abstract: A digitally signed file system in which data, metadata and files are objects, each object having a globally unique and content-derived fingerprint and wherein object references are mapped by the fingerprints; the file system has a root object comprising a mapping of all object fingerprints in the file system, such that a change to the file system results in a change in the root object, and tracking changes in the root object provides a history of file system activity.

Abstract: Method and apparatus for replicating data structures over a network in which each data structure is assigned an owner node among a plurality of networked peer nodes. Preferably that owner can be ascertained through information in the data structure. When an update to the data structure is desired by a non-owner, a request to modify the data structure is sent out on the network and when received by the owner, the owner performs the modification. The owner node can then notify the other nodes regarding the update. The method, implemented through a single-writer, multiple-reader paradigm, insures availability, partition tolerance and eventual consistency; it avoids the high overhead costs and single point of failure drawbacks of the prior art centralized management and locking protocols. Administrators can connect to any peer node in the network to manage, monitor and request modifications to a data structure.

Abstract: Method and apparatus for constructing an index that scales to a large number of records and provides a high transaction rate. New data structures and methods are provided to ensure that an indexing algorithm performs in a way that is natural (efficient) to the algorithm, while a non-uniform access memory device sees IO (input/output) traffic that is efficient for the memory device. One data structure, a translation table, is created that maps logical buckets as viewed by the indexing algorithm to physical buckets on the memory device. This mapping is such that write performance to non-uniform access SSD and flash devices is enhanced. Another data structure, an associative cache is used to collect buckets and write them out sequentially to the memory device as large sequential writes. Methods are used to populate the cache with buckets (of records) that are required by the indexing algorithm.

Abstract: A digitally signed file system in which data, metadata and files are objects, each object having a globally unique and content-derived fingerprint and wherein object references are mapped by the fingerprints; the file system has a root object comprising a mapping of ail object fingerprints in the file system, such that a change to the file system results in a change in the root object, and tracking changes in the root object provides a history of file system activity.

Abstract: A digitally signed file system in which data, metadata and files are objects, each object having a globally unique and content-derived fingerprint and wherein object references are mapped by the fingerprints; the file system has a root object comprising a mapping of ail object fingerprints in the file system, such that a change to the file system results in a change in the root object, and tracking changes in the root object provides a history of file system activity.

Abstract: Method and apparatus for locating data on disk storage, wherein multiple instances of data can be stored at different locations to satisfy different use requirements such as read access, write access, and data security. The method allows a data storage system, such as a file system, to provide both read optimized and write optimized performance on disk storage of different types (e.g., sizes and speed).

Abstract: Method and apparatus for storing records in non-uniform access memory. In various embodiments, the placement of records is localized in one or more regions of the memory. This can be accomplished utilizing different ordered lists of hash functions to preferentially map records to different regions of the memory to achieve one or more performance characteristics or to account for differences in the underlying memory technologies. For example, one ordered list of hash functions may localize the data for more rapid access. Another list of hash functions may localize the data that is expected to have a relatively short lifetime. Localizing such data may significantly improve the erasure performance and/or memory lifetime, e.g., by concentrating the obsolete data elements in one location. Thus, the two or more lists of ordered hash functions may improve one or more of access latency, memory lifetime, and/or operation rate.

Abstract: Method and apparatus for replicating data structures over a network in which each data structure is assigned an owner node among a plurality of networked peer nodes. Preferably that owner can be ascertained through information in the data structure. When an update to the data structure is desired by a non-owner, a request to modify the data structure is sent out on the network and when received by the owner, the owner performs the modification. The owner node can then notify the other nodes regarding the update. The method, implemented through a single-writer, multiple-reader paradigm, insures availability, partition tolerance and eventual consistency; it avoids the high overhead costs and single point of failure drawbacks of the prior art centralized management and locking protocols. Administrators can connect to any peer node in the network to manage, monitor and request modifications to a data structure.

Abstract: A digitally signed file system in which data, metadata and files are objects, each object having a globally unique and content-derived fingerprint and wherein object references are mapped by the fingerprints; the file system has a root object comprising a mapping of all object fingerprints in the file system, such that a change to the file system results in a change in the root object, and tracking changes in the root object provides a history of file system activity.

Abstract: Method and apparatus for replicating data structures over a network in which each data structure is assigned an owner node among a plurality of networked peer nodes. Preferably that owner can be ascertained through information in the data structure. When an update to the data structure is desired by a non-owner, a request to modify the data structure is sent out on the network and when received by the owner, the owner performs the modification. The owner node can then notify the other nodes regarding the update. The method, implemented through a single-writer, multiple-reader paradigm, insures availability, partition tolerance and eventual consistency; it avoids the high overhead costs and single point of failure drawbacks of the prior art centralized management and locking protocols. Administrators can connect to any peer node in the network to manage, monitor and request modifications to a data structure.

Abstract: A digitally signed file system in which data, metadata and files are objects, each object having a globally unique and content-derived fingerprint and wherein object references are mapped by the fingerprints; the file system has a root object comprising a mapping of all object fingerprints in the file system, such that a change to the file system results in a change in the root object, and tracking changes in the root object provides a history of file system activity.

Abstract: Methods and systems are provided for tracking object instances stored on a plurality of network nodes, which tracking enables a global determination of when an object has no references across the networked nodes and can be safely de-allocated. According to one aspect of the invention, each node has a local object store for tracking and optionally storing objects on the node, and the local object stores collectively share the locally stored instances of the objects across the network. One or more applications, e.g., a file system and/or a storage system, use the local object stores for storing all persistent data of the application as objects.

Abstract: Method and apparatus for storing records in non-uniform access memory. In various embodiments, the placement of records is localized in one or more regions of the memory. This can be accomplished utilizing different ordered lists of hash functions to preferentially map records to different regions of the memory to achieve one or more performance characteristics or to account for differences in the underlying memory technologies. For example, one ordered list of hash functions may localize the data for more rapid access. Another list of hash functions may localize the data that is expected to have a relatively short lifetime. Localizing such data may significantly improve the erasure performance and/or memory lifetime, e.g., by concentrating the obsolete data elements in one location. Thus, the two or more lists of ordered hash functions may improve one or more of access latency, memory lifetime, and/or operation rate.

Abstract: Methods and systems are provided for tracking object instances stored on a plurality of network nodes, which tracking enables a global determination of when an object has no references across the networked nodes and can be safely de-allocated. According to one aspect of the invention, each node has a local object store for tracking and optionally storing objects on the node, and the local object stores collectively share the locally stored instances of the objects across the network. One or more applications, e.g., a file system and/or a storage system, use the local object stores for storing all persistent data of the application as objects.

Abstract: Method and apparatus for storing records in non-uniform access memory. In various embodiments, the placement of records is localized in one or more regions of the memory. This can be accomplished utilizing different ordered lists of hash functions to preferentially map records to different regions of the memory to achieve one or more performance characteristics or to account for differences in the underlying memory technologies. For example, one ordered list of hash functions may localize the data for more rapid access. Another list of hash functions may localize the data that is expected to have a relatively short lifetime. Localizing such data may significantly improve the erasure performance and/or memory lifetime, e.g., by concentrating the obsolete data elements in one location. Thus, the two or more lists of ordered hash functions may improve one or more of access latency, memory lifetime, and/or operation rate.

Abstract: Methods and systems are provided for tracking object instances stored on a plurality of network nodes, which tracking enables a global determination of when an object has no references across the networked nodes and can be safely de-allocated. According to one aspect of the invention, each node has a local object store for tracking and optionally storing objects on the node, and the local object stores collectively share the locally stored instances of the objects across the network. One or more applications, e.g., a file system and/or a storage system, use the local object stores for storing all persistent data of the application as objects.

Abstract: Apparatus and method for placing data based on the content of the data in random access memory such that indexing operations are not required. A strong (e.g., cryptographic) hash is applied to a data element resulting in a signature. A weaker hash function is then applied to the signature to generate a storage location in memory for the data element. The weaker hash function assigns multiple data elements to the same storage location while the signature comprises a unique identifier for locating a particular data element at this location. In one embodiment a plurality of weak hash functions are applied successively to increase storage space utilization. In other embodiments, the assigned storage location can be determined by one or more attributes of the data element and/or the storage technology, e.g, long-lived versus short-lived data and/or different regions of the memory having different performance (e.g., access latency memory lifetime) characteristics.

Abstract: Methods and systems are provided for tracking object instances stored on a plurality of network nodes, which tracking enables a global determination of when an object has no references across the networked nodes and can be safely de-allocated. According to one aspect of the invention, each node has a local object store for tracking and optionally storing objects on the node, and the local object stores collectively share the locally stored instances of the objects across the network. One or more applications, e.g., a file system and/or a storage system, use the local object stores for storing all persistent data of the application as objects.

Abstract: Method and apparatus for constructing an index that scales to a large number of records and provides a high transaction rate. New data structures and methods are provided to ensure that an indexing algorithm performs in a way that is natural (efficient) to the algorithm, while a non-uniform access memory device sees IO (input/output) traffic that is efficient for the memory device. One data structure, a translation table, is created that maps logical buckets as viewed by the indexing algorithm to physical buckets on the memory device. This mapping is such that write performance to non-uniform access SSD and flash devices is enhanced. Another data structure, an associative cache is used to collect buckets and write them out sequentially to the memory device as large sequential writes. Methods are used to populate the cache with buckets (of records) that are required by the indexing algorithm.

Abstract: Methods and systems are provided for tracking object instances stored on a plurality of network nodes, which tracking enables a global determination of when an object has no references across the networked nodes and can be safely de-allocated. According to one aspect of the invention, each node has a local object store for tracking and optionally storing objects on the node, and the local object stores collectively share the locally stored instances of the objects across the network. One or more applications, e.g., a file system and/or a storage system, use the local object stores for storing all persistent data of the application as objects.