Abstract: Embodiments include methods, apparatus, and systems for data transfer in storage systems. One embodiment includes a method that transmits a state of cached write data and mapping metadata associated with a disk group from a first array to a second array and then transfers access to the disk group from the first array to the second array while host applications continue to access data in the disk group.

Abstract: Embodiments of the present invention include array-cluster systems, and methods employed in array-cluster systems, that allow snapshot data to be distributed over multiple arrays within an array cluster. By distributing snapshot data over multiple arrays within an array cluster, the load, generally related to the number of access operations directed to the arrays within an array cluster, may be more evenly distributed among the arrays of an array cluster, preventing increased latencies associated with overloading individual arrays Distributed snapshots may also facilitate high availability and fault tolerance within an array cluster.

Abstract: Embodiments include methods, apparatus, and systems for managing resources in a storage system. One embodiment includes a method that discovers storage resources for arrays in a cluster storage system. A table defines how the resources are divided among the arrays and is provided to the arrays so each array can identify which resources to manage.

Abstract: Various embodiments of the present invention provide fault-tolerant, redundancy-based data-storage systems that rely on disk-controller-implemented error detection and error correction, at the disk-block level, and RAID-controller-implemented data-redundancy methods, at the disk and disk-stripe level, in order to provide comprehensive, efficient, and system-wide error detection and error correction. Embodiments of the present invention use disk-level and stripe-level data redundancy to provide error detection and error correction for stored data objects, obviating the need for certain costly, intermediate levels of error detection and error correction commonly employed in currently available fault-tolerant, redundancy-based data-storage systems.

Abstract: There is provided a system and method of mass storage. The method includes dividing storage units into standard size blocks and upon receiving a write request from an application, generating EDC data for user application data associated with the write request. The method also includes compressing the user application data using a lossless compression technique and storing the user application data and the EDC data together in a single block in a primary data area if the lossless compression technique is successful.

Abstract: Embodiments of the present invention are directed to methods, and distributed data-storage systems employing the methods, for recovering redundancy within a distributed data-storage system upon failure of one or more mass-storage devices within a component data-storage system of the distributed data-storage system. In certain embodiments, failure of a mass-storage device within a component data-storage system elicits a redundancy-recovery operation in which segments affected by the mass-storage-device failure or failures are moved, by a process referred to as “migration,” to other component data-storage systems of the distributed data-storage system, and are recovered as a by-product of migration.

Abstract: A storage system includes plural storage units having respective storage controllers and associated caches. A first one of the storage units further includes an internal workload generator to initiate a data operation with respect to at least one destination storage unit, where the data operation is associated with tag information to affect a caching algorithm used by the cache of the at least one destination storage unit. The at least one destination storage unit includes at least one of the plural storage units.

Abstract: In one embodiment, a storage controller comprises a first port that provides an interface to a host computer, a second port that provides an interface to a storage device, a processor, and a memory module communicatively connected to the processor and comprising logic instructions stored on a computer readable storage medium which, when executed by the processor, configure the processor to copy a logical disk mapping from a first storage array managed by a source storage controller to a second storage array managed by a destination storage controller by performing operations comprising obtaining, in the source storage controller, an object identifier listing for use with the logical disk mappings in the destination storage controller, copying, in the source storage controller, contents of logical disk mappings for use in the first storage array from a first storage container to a second storage container, and replacing, in the source storage controller, object identifiers associated with the logical disk mapp

Abstract: Embodiments include methods, apparatus, and systems for managing resources in a storage system. One embodiment includes a method that discovers storage resources for arrays in a cluster storage system. A table defines how the resources are divided among the arrays and is provided to the arrays so each array can identify which resources to manage.

Abstract: Embodiments of the present invention include array-cluster systems, and methods employed in array-cluster systems, that allow snapshot data to be distributed over multiple arrays within an array cluster. By distributing snapshot data over multiple arrays within an array cluster, the load, generally related to the number of access operations directed to the arrays within an array cluster, may be more evenly distributed among the arrays of an array cluster, preventing increased latencies associated with overloading individual arrays Distributed snapshots may also facilitate high availability and fault tolerance within an array cluster.

Abstract: Embodiments include methods, apparatus, and systems for data transfer in storage systems. One embodiment includes a method that transmits a state of cached write data and mapping metadata associated with a disk group from a first array to a second array and then transfers access to the disk group from the first array to the second array while host applications continue to access data in the disk group.

Abstract: Embodiments of the present invention are directed to methods, and distributed data-storage systems employing the methods, for recovering redundancy within a distributed data-storage system upon failure of one or more mass-storage devices within a component data-storage system of the distributed data-storage system. In certain embodiments, failure of a mass-storage device within a component data-storage system elicits a redundancy-recovery operation in which segments affected by the mass-storage-device failure or failures are moved, by a process referred to as “migration,” to other component data-storage systems of the distributed data-storage system, and are recovered as a by-product of migration.

Abstract: Various embodiments of the present invention provide fault-tolerant, redundancy-based data-storage systems that rely on disk-controller-implemented error detection and error correction, at the disk-block level, and RAID-controller-implemented data-redundancy methods, at the disk and disk-stripe level, in order to provide comprehensive, efficient, and system-wide error detection and error correction. Embodiments of the present invention use disk-level and stripe-level data redundancy to provide error detection and error correction for stored data objects, obviating the need for certain costly, intermediate levels of error detection and error correction commonly employed in currently available fault-tolerant, redundancy-based data-storage systems.

Abstract: There is provided a system and method of mass storage. The method includes dividing storage units into standard sized blocks and upon receiving a write request from an application, generating EDC data for user application data associated with the write request. The method also includes compressing the user application data using a lossless compression technique and storing the user application data and the EDC data together in a single block in a primary data area if the lossless compression technique is successful.

Abstract: A storage system includes plural storage units having respective storage controllers and associated caches. A first one of the storage units further includes an internal workload generator to initiate a data operation with respect to at least one destination storage unit, where the data operation is associated with tag information to affect a caching algorithm used by the cache of the at least one destination storage unit. The at least one destination storage unit includes at least one of the plural storage units.

Abstract: Computer systems, virtual storage systems, and virtual storage system operational methods are described. According to one aspect, a computer system includes a virtual storage system including a physical storage space, a virtual storage space, and a non-guaranteed available capacity utilized to generate a non-guaranteed snapshot volumes of virtual storage volumes of the virtual storage space, wherein the virtual storage system is configured to monitor the non-guaranteed available capacity and to present a report regarding the non-guaranteed available capacity responsive to the monitoring and a host configured to execute an application wherein generation of a non-guaranteed snapshot volume of at least one of the virtual storage volumes is desired, to access the report to determine the non-guaranteed available capacity, and to issue a request to the virtual storage system to generate the at least one non-guaranteed snapshot volume of the at least one virtual storage volume responsive to the accessing.

Abstract: A disk controller includes memory that is accessible by both a microprocessor and hardware parity logic. Parity-related operations are identified by scenario, and parity coefficient subsets are stored in a memory table for each different parity-related calculation scenario. To perform a particular parity-related operation, the microprocessor determines the operation's scenario and identifies the corresponding coefficient subset. The hardware parity logic is then instructed to perform the appropriate parity computation, using the identified coefficient subset.

Abstract: Computer systems, virtual storage systems, and virtual storage system operational methods are described.

Abstract: A data access task distributor receives a request to perform a data access task. The request is received by a first processor, which identifies an appropriate processor to process the request. The first processor processes the request if the first processor is the appropriate processor to process the request. The first processor forwards the request to the appropriate processor if the first processor is not the appropriate processor to process the request. The first processor identifies the appropriate processor by retrieving data from a table that identifies the types of data access tasks handled by each processor.

Abstract: A disk controller includes memory that is accessible by both a microprocessor and hardware parity logic. Parity-related operations are identified by scenario, and parity coefficient subsets are stored in a memory table for each different parity-related calculation scenario. To perform a particular parity-related operation, the microprocessor determines the operation's scenario and identifies the corresponding coefficient subset. The hardware parity logic is then instructed to perform the appropriate parity computation, using the identified coefficient subset.