Abstract: Aspects of disclosure provide methods, systems, and computer-readable media for direct data displacement. The methods include in view of a write request pertaining to a first object, determining, based on a first signature of the first object, whether an index of a storage system comprises an existing object record pertaining to the first object; and in response to determining that the index of the storage system does not include an existing object record pertaining to the first signature, creating a first object record in the index comprising the first signature and a reference count. The methods further include in response to determining that the index of the storage system includes an existing object record pertaining to the first signature, updating a reference count associated with the first object stored in the existing object.

Abstract: Aspects of disclosure provide methods, systems, and computer-readable media for direct data displacement. The methods include in view of a write request pertaining to a first object, determining, based on a first signature of the first object, whether an index of a storage system comprises an existing object record pertaining to the first object; and in response to determining that the index of the storage system does not include an existing object record pertaining to the first signature, creating a first object record in the index comprising the first signature and a reference count. The methods further include in response to determining that the index of the storage system includes an existing object record pertaining to the first signature, updating a reference count associated with the first object stored in the existing object.

Abstract: Methods, apparatuses, systems, and media for implementing a persistent read cache in a scale out storage system are disclosed to reduce access latency and achieve higher performance. Both the cached data blocks and distributed data placements are referenced by their unique content identifiers and are deduplicated. The persistent read cache spans across node reboots and is inherently coherent across all storage nodes without a distributed lock manager. The cached data blocks share the same storage pool as distributed data placements without costing storage capacity. A cached data block can become a distributed data placement or vice versa without moving the physical data block. Methods are also disclosed to reduce time to performance for logical device mobility.

Abstract: Methods, systems, and media for supporting snapshots and clones in a scale out storage system are disclosed. The system maintains first metadata that maps logical addresses of logical data blocks to corresponding content IDs, a distributed hash table that maps content IDs to corresponding node IDs, and second metadata that maps content IDs to corresponding physical addresses of physical data blocks. Clones are created by mapping each logical block address of each clone to the content ID associated with its corresponding logical block address of the original and incrementing the reference counts in the second metadata. The task of incrementing reference counts in the second metadata can be distributed across multiple storage nodes. A logical device can be designated as a golden image. Clones of a golden image are created by decrementing its clone credit without incrementing the reference counts in the second metadata.

Abstract: A method for managing metadata in a scale out storage system is disclosed. The system includes a plurality of nodes, a storage pool, first metadata that maps logical addresses of logical data blocks to corresponding content identifiers, and second metadata that maps content identifiers to corresponding physical addresses of physical data blocks in the storage pool and maintains a reference count. During an add-a-node operation, the processors are configured to move from the existing nodes to the new node some of its physical data blocks, their content identifiers and reference counts in the second metadata without accessing or altering the first metadata. A method is disclosed to move a logical device from one node to another by de-activating the logical device's first metadata on the first node and activating and retrieving the logical device's first metadata on the second node.

Abstract: A method for managing metadata in a scale out storage system is disclosed. The system includes a plurality of nodes, a storage pool, first metadata that maps logical addresses of logical data blocks to corresponding content identifiers, and second metadata that maps content identifiers to corresponding physical addresses of physical data blocks in the storage pool and maintains a reference count. During an add-a-node operation, the processors are configured to move from the existing nodes to the new node some of its physical data blocks, their content identifiers and reference counts in the second metadata without accessing or altering the first metadata. A method is also disclosed to move a logical device from one node to another by de-activating the logical device's first metadata on the first node and activating and retrieving the logical device's first metadata on the second node.

Abstract: A method for managing metadata in a scale out storage system is disclosed. The system includes a plurality of nodes, a storage pool, first metadata that maps logical addresses of logical data blocks to corresponding content identifiers, and second metadata that maps content identifiers to corresponding physical addresses of physical data blocks in the storage pool and maintains a reference count. During an add-a-node operation, the processors are configured to move from the existing nodes to the new node some of its physical data blocks, their content identifiers and reference counts in the second metadata without accessing or altering the first metadata. A method is disclosed to move a logical device from one node to another by de-activating the logical device's first metadata on the first node and activating and retrieving the logical device's first metadata on the second node.

Abstract: A method for managing metadata in a storage system is disclosed. The system includes a processor, a storage medium, a first metadata table that maps every data block's LBN to its unique content ID, and a second metadata table that maps every content ID to its PBN on the storage medium. During a data movement process, the processor is configured to determine the content ID of the data block and update its entry in the second metadata table without accessing the first metadata table. A method is also disclosed to reduce the size of the first metadata table. Only content ID is stored in the first metadata table and its LBN is determined by the metadata entry's relative position in the table. Metadata entries are stored in metadata blocks and deduplicated.

Abstract: A method for managing metadata in a scale out storage system is disclosed. The system includes a plurality of nodes, a storage pool, first metadata that maps logical addresses of logical data blocks to corresponding content, and second metadata that maps content identifiers to corresponding physical addresses of physical data blocks in the storage pool and maintains a reference count. During an add-a-node operation, the processors are configured to move from the existing nodes to the new node some of its physical data blocks, their content identifiers and reference counts in the second metadata without accessing or altering the first metadata. A method is also disclosed to move a logical device from one node to another by de-activating the logical device's first metadata on the first node and activating and retrieving the logical device's first metadata on the second node.

Abstract: A method for managing metadata in a storage system is disclosed. The system includes a processor, a storage medium, a first metadata table that maps every data block's LBN to its unique content ID, and a second metadata table that maps every content ID to its PBN on the storage medium. During a data movement process, the processor is configured to determine the content ID of the data block and update its entry in the second metadata table without accessing the first metadata table. A method is also disclosed to reduce the size of the first metadata table. Only content ID is stored in the first metadata table and its LBN is determined by the metadata entry's relative position in the table. Metadata entries are stored in metadata blocks and deduplicated.

Abstract: Described are apparatuses and methods for remote recording of digital data. A remote server digital video recorder (RS-DVR) server system includes one or more computer readable storage devices and a digital video recorder (DVR) server. The DVR server includes an input controller, a buffer unit, and a storage controller. The input controller receives an original data stream. The buffer unit is coupled to the input controller and receives and stores at least a portion of the original data stream from the input controller. The storage controller is coupled to the buffer unit and controls direct memory access to the one or more computer readable storage devices for writing one or more subscriber data streams copied from the original data stream. Each subscriber data stream is associated with a subscriber and written to a storage device location in the one or more computer readable storage devices associated with the subscriber.

Abstract: An apparatus provides coherent data copying operations where data replication is controlled by a source storage controller directly to a destination controller and managed by a remote application. The apparatus generates a snapshot version for each source data block changed by one or more write operations to the source data block during the course of a copy operation; and copies each block of the source data to a corresponding block in the destination data in the absence of the snapshot version of the block and otherwise copying the snapshot version of the source data block to the corresponding block in the destination data.