Abstract: A system, method, and machine-readable storage medium for determining an amount of unique data in a distributed storage system are provided. In some embodiments, a combined efficiency set for a first data set stored in the distributed storage system, such as at a volume, may be generated. The first data set may include a first subset of data and a second subset of data in the distributed storage system. Additionally, a set of efficiency sets for the first subset of data may be generated. A set difference based on the combined efficiency set and the set of efficiency sets may be computed. An amount of memory used for storing unique data of the second subset of data may be estimated based on the set difference. The unique data may be present in the second subset of data but absent from the first subset of data.

Abstract: Systems and methods are described for a streamlined garbage collection process during which data integrity checking is also performed for a distributed key-value (KV) store utilized by a distributed storage system. According to one embodiment, by making use of full or truncated block IDs (rather than an intermediate probabilistic data structure, such as a Bloom filter) for garbage collection, data integrity checking can be performed concurrently almost for free. During garbage collection, a block ID compare list may be compared to block IDs within the distributed KV store. If a particular block ID is present in the distributed KV store but is missing from the block ID compare list, the corresponding data block represents garbage to be collected. If the particular block ID is present in the block ID compare list but missing from the distributed KV store, a data integrity error has been identified.

Abstract: Systems and methods are described for a streamlined garbage collection process during which data integrity checking is also performed for a distributed key-value (KV) store utilized by a distributed storage management system. According to one embodiment, by making use of full or truncated block IDs (rather than an intermediate probabilistic data structure, such as a Bloom filter) for garbage collection, data integrity checking can be performed concurrently almost for free. During garbage collection, a block ID compare list is compared to block IDs within the distributed KV store. If a particular block ID is present in the distributed KV store but is missing from the block ID compare list, the corresponding data block represents garbage to be collected. If the particular block ID is present in the block ID compare list but missing from the distributed KV store, a data integrity error has been identified.

Abstract: A system, method, and machine-readable storage medium for determining an amount of unique data in a distributed storage system are provided. In some embodiments, a combined efficiency set for a first data set stored in the distributed storage system, such as at a volume, may be generated. The first data set may include a first subset of data and a second subset of data in the distributed storage system. Additionally, a set of efficiency sets for the first subset of data may be generated. A set difference based on the combined efficiency set and the set of efficiency sets may be computed. An amount of memory used for storing unique data of the second subset of data may be estimated based on the set difference. The unique data may be present in the second subset of data but absent from the first subset of data.

Abstract: Systems and methods are described for a streamlined garbage collection process during which data integrity checking is also performed for a distributed key-value (KV) store utilized by a distributed storage management system. According to one embodiment, by making use of full or truncated block IDs (rather than an intermediate probabilistic data structure, such as a Bloom filter) for garbage collection, data integrity checking can be performed concurrently almost for free. During garbage collection, a block ID compare list is compared to block IDs within the distributed KV store. If a particular block ID is present in the distributed KV store but is missing from the block ID compare list, the corresponding data block represents garbage to be collected. If the particular block ID is present in the block ID compare list but missing from the distributed KV store, a data integrity error has been identified.

Abstract: A system, method, and machine-readable storage medium for determining an amount of unique data in a distributed storage system are provided. In some embodiments, a combined efficiency set for a first data set stored in the distributed storage system, such as at a volume, may be generated. The first data set may include a first subset of data and a second subset of data in the distributed storage system. Additionally, a set of efficiency sets for the first subset of data may be generated. A set difference based on the combined efficiency set and the set of efficiency sets may be computed. An amount of memory used for storing unique data of the second subset of data may be estimated based on the set difference. The unique data may be present in the second subset of data but absent from the first subset of data.

Abstract: A system, method, and machine-readable storage medium for determining an amount of unique data in a distributed storage system are provided. In some embodiments, a combined efficiency set for a first data set stored in the distributed storage system, such as at a volume, may be generated. The first data set may include a first subset of data and a second subset of data in the distributed storage system. Additionally, a set of efficiency sets for the first subset of data may be generated. A set difference based on the combined efficiency set and the set of efficiency sets may be computed. An amount of memory used for storing unique data of the second subset of data may be estimated based on the set difference. The unique data may be present in the second subset of data but absent from the first subset of data.

Abstract: A system, method, and machine-readable storage medium for determining an amount of unique data in a distributed storage system are provided. In some embodiments, a combined efficiency set for a first data set stored in the distributed storage system, such as at a volume, may be generated. The first data set may include a first subset of data and a second subset of data in the distributed storage system. Additionally, a set of efficiency sets for the first subset of data may be generated. A set difference based on the combined efficiency set and the set of efficiency sets may be computed. An amount of memory used for storing unique data of the second subset of data may be estimated based on the set difference. The unique data may be present in the second subset of data but absent from the first subset of data.

Abstract: A method of data replication from a first data storage device to a second data storage device. The method may include generating, at the first data storage device, at spaced time intervals, a plurality of snapshots for a logical data volume of the first data storage device, the logical data volume being an abstraction of data blocks from one or more physical storage devices, each snapshot identifying changes of data for at least a portion of the logical data volume since a most previous snapshot. Also at the first data storage device, the method includes generating a delta volume, the delta volume indicating changes in the data of at least a portion of the logical data volume between two non-consecutive snapshots. The method further involves replicating the delta volume to the second data storage device, and replicating the changes to the data indicated therein at the second data storage device.

Abstract: The present disclosure relates generally to a method and system for creating, replicating, and providing access to virtual snapshots of a disk storage block of a disk storage system or subsystem. In one embodiment, the present disclosure relates to a virtual snapshot accessible to local users of a local data storage device. The virtual snapshot may direct local users to a snapshot stored on computer-readable storage medium at a remote data storage site, but give the appearance as if data of the corresponding snapshot is stored locally. The virtual snapshot is replaced by replication of the snapshot from the remote data storage site to the local data storage device. Each snapshot may relate to data of a logical data volume, the logical data volume being an abstraction of data blocks from one or more physical storage devices.

Abstract: A method of data replication from a first data storage device to a second data storage device. The method may include generating, at the first data storage device, at spaced time intervals, a plurality of snapshots for a logical data volume of the first data storage device, the logical data volume being an abstraction of data blocks from one or more physical storage devices, each snapshot identifying changes of data for at least a portion of the logical data volume since a most previous snapshot. Also at the first data storage device, the method includes generating a delta volume, the delta volume indicating changes in the data of at least a portion of the logical data volume between two non-consecutive snapshots. The method further involves replicating the delta volume to the second data storage device, and replicating the changes to the data indicated therein at the second data storage device.

Abstract: A method of data replication from a first data storage device to a second data storage device. The method may include generating, at the first data storage device, at spaced time intervals, a plurality of snapshots for a logical data volume of the first data storage device, the logical data volume being an abstraction of data blocks from one or more physical storage devices, each snapshot identifying changes of data for at least a portion of the logical data volume since a most previous snapshot. Also at the first data storage device, the method includes generating a delta volume, the delta volume indicating changes in the data of at least a portion of the logical data volume between two non-consecutive snapshots. The method further involves replicating the delta volume to the second data storage device, and replicating the changes to the data indicated therein at the second data storage device.

Abstract: The present disclosure relates generally to a method and system for creating, replicating, and providing access to virtual snapshots of a disk storage block of a disk storage system or subsystem. In one embodiment, the present disclosure relates to a virtual snapshot accessible to local users of a local data storage device. The virtual snapshot may direct local users to a snapshot stored on computer-readable storage medium at a remote data storage site, but give the appearance as if data of the corresponding snapshot is stored locally. The virtual snapshot is replaced by replication of the snapshot from the remote data storage site to the local data storage device. Each snapshot may relate to data of a logical data volume, the logical data volume being an abstraction of data blocks from one or more physical storage devices.

Abstract: The present disclosure relates generally to a method and system for creating, replicating, and providing access to virtual snapshots of a disk storage block of a disk storage system or subsystem. In one embodiment, the present disclosure relates to a virtual snapshot accessible to local users of a local data storage device. The virtual snapshot may direct local users to a snapshot stored on computer-readable storage medium at a remote data storage site, but give the appearance as if data of the corresponding snapshot is stored locally. The virtual snapshot is replaced by replication of the snapshot from the remote data storage site to the local data storage device. Each snapshot may relate to data of a logical data volume, the logical data volume being an abstraction of data blocks from one or more physical storage devices.

Abstract: A method of data replication from a first data storage device to a second data storage device. The method may include generating, at the first data storage device, at spaced time intervals, a plurality of snapshots for a logical data volume of the first data storage device, the logical data volume being an abstraction of data blocks from one or more physical storage devices, each snapshot identifying changes of data for at least a portion of the logical data volume since a most previous snapshot. Also at the first data storage device, the method includes generating a delta volume, the delta volume indicating changes in the data of at least a portion of the logical data volume between two non-consecutive snapshots. The method further involves replicating the delta volume to the second data storage device, and replicating the changes to the data indicated therein at the second data storage device.

Abstract: A fiber channel storage area network (SAN) provides virtualized storage space for a number of servers to a number of virtual disks implemented on various virtual redundant array of inexpensive disks (RAID) devices striped across a plurality of physical disk drives. The SAN includes plural controllers and communication paths to allow for fail-safe and fail-over operation. The plural controllers can be loosely-coupled to provide n-way redundancy and have more than one independent channel for communicating with one another. In the event of a failure involving a controller or controller interface, the virtual disks that are accessed via the affected interfaces are re-mapped to another interface in order to continue to provide high data availability. In particular, those targets, or virtual disks, which are owned by a failed device (e.g.

Abstract: A fiber channel storage area network (SAN) provides virtualized storage space for a number of servers to a number of virtual disks implemented on various virtual redundant array of inexpensive disks (RAID) devices striped across a plurality of physical disk drives. The SAN includes plural controllers and communication paths to allow for fail-safe and fail-over operation. The plural controllers can be loosely-coupled to provide n-way redundancy and more than one independent channel for communicating with one another. In the event of a failure involving a controller or controller interface, the virtual disks that are accessed via the affected interfaces are re-mapped to another interface in order to continue to provide high data availability. In particular a resource re-allocation routine operating on one of the controllers employs predetermined criteria against a family of potential back-up controllers in order to select appropriate back-up controllers for a particular device that fails.

Abstract: A fiber channel storage area network (SAN) provides virtualized storage space for a number of servers to a number of virtual disks implemented on various virtual redundant array of inexpensive disks (RAID) devices striped across a plurality of physical disk drives. The SAN includes plural controllers and communication paths to allow for fail-safe and fail-over operation. The plural controllers can be loosely-coupled to provide n-way redundancy and have more than one independent channel for communicating with one another. In the event of a failure involving a controller or controller interface, the virtual disks that are accessed via the affected interfaces are re-mapped to another interface in order to continue to provide high data availability.

Abstract: A fibre channel storage area network (SAN) provides virtualized storage space for a number of servers to a number of virtual disks implemented on various virtual redundant array of inexpensive disks (RAID) devices striped across a plurality of physical disk drives. The SAN includes plural controllers and communication paths to allow for fail-safe and fail-over operation. The plural controllers can be loosely-coupled to provide n-way redundancy and have more than one independent channel for communicating with one another. In the event of a failure involving a controller or controller interface, the virtual disks that are accessed via the affected interfaces are re-mapped to another interface in order to continue to provide high data availability. In particular, a common memory storage device is connected to the back-ends of every controller to provide a storage area.

Abstract: A fibre channel storage area network (SAN) provides virtualized storage space for a number of servers to a number of virtual disks implemented on various virtual redundant array of inexpensive disks (RAID) devices striped across a plurality of physical disk drives. The SAN includes plural controllers and communication paths to allow for fail-safe and fail-over operation. The plural controllers can be loosely-coupled to provide n-way redundancy and have more than one independent channel for communicating with one another. In the event of a failure involving a controller or controller interface, the virtual disks that are accessed via the affected interfaces are re-mapped to another interface in order to continue to provide high data availability.