Abstract: Stream locality delta compression is disclosed. A previous stream indicated locale of data segments is selected. A first data segment is then determined to be similar to a data segment in the stream indicated locale.

Abstract: Storage of data segments is disclosed. For each segment, a similar segment to the segment is identified, wherein the similar segment is already managed by a cluster node. In the event the similar segment is identified, a reference to the similar segment and a delta between the similar segment and the segment are caused to be stored instead of the segment.

Abstract: Cluster storage is disclosed. A data stream or a data block is received. The data stream or the data block is broken into segments. For each segment, a cluster node is selected, and a portion of the segment smaller than the segment is identified that is a duplicate of a portion of a segment already managed by the cluster node.

Abstract: Cluster storage is disclosed. A data stream or a data block is received. The data stream or the data block is broken into segments. For each segment, a cluster node is selected, and a portion of the segment smaller than the segment is identified that is a duplicate of a portion of a segment already managed by the cluster node.

Abstract: Cluster storage is disclosed. A data stream or a data block is received. The data stream or the data block is broken into segments. For each segment, a cluster node is selected, and a portion of the segment smaller than the segment is identified that is a duplicate of a portion of a segment already managed by the cluster node.

Abstract: Storage of data segments is disclosed. For each segment, a similar segment to the segment is identified, wherein the similar segment is already managed by a cluster node. In the event the similar segment is identified, a reference to the similar segment and a delta between the similar segment and the segment are caused to be stored instead of the segment.

Abstract: Cluster storage is disclosed. A data stream or a data block is received. The data stream or the data block is broken into segments. For each segment, a cluster node is selected, and in the event that a similar segment to the segment is identified that is already managed by the selected cluster node, a reference to the similar segment and a delta between the similar segment and the segment is caused to be stored on the selected cluster node.

Abstract: File system replication includes determining whether one of a plurality of files included in an original file system has been updated since a previous replication, the file having a plurality of data segments, and in the event that the file has been updated, locating among the plurality of data segments a previously stored data segment that is newly referenced by the file, and that does not require replication.

Abstract: Delta compression after identity deduplication is disclosed. A first data segment is determined to be identical to a first previous data segment. A second data segment, not determined to be identical to a second previous data segment, is then determined to be similar to a third previous data segment.

Abstract: A method for storing data is disclosed. The method comprises receiving a data stream comprising a plurality of data segments and preliminarily checking in a memory having a relatively low latency whether one of the plurality of data segments has been stored previously. The method further comprises in the event that the preliminary check does not conclusively determine whether the data segment has been stored previously, limiting checking in a memory having a relatively high latency to conclusively determine whether the data segment has been previously stored, and in the event that checking is limited or in the event that the check in the memory having relatively high latency conclusively determines the data segment has not been previously stored, storing the data segment.

Abstract: Cluster storage is disclosed. A data stream or a data block is received. The data stream or the data block is broken into segments. For each segment, a cluster node is selected, and in the event that a similar segment to the segment is identified that is already managed by the selected cluster node, a reference to the similar segment and a delta between the similar segment and the segment is caused to be stored on the selected cluster node.

Abstract: Cluster storage is disclosed. A data stream or a data block is received. The data stream or the data block is broken into segments. For each segment, a cluster node is selected, and a portion of the segment smaller than the segment is identified that is a duplicate of a portion of a segment already managed by the cluster node.

Abstract: Cluster storage is disclosed. A data stream or a data block is received. The data stream or the data block is broken into segments. For each segment, a cluster node is selected, and a portion of the segment smaller than the segment is identified that is a duplicate of a portion of a segment already managed by the cluster node.

Abstract: File system replication includes determining whether one of a plurality of files included in an original file system has been updated since a previous replication, the file having a plurality of data segments, and in the event that the file has been updated, locating among the plurality of data segments a previously stored data segment that is newly referenced by the file, and that does not require replication.

Abstract: This invention describes a high-performance, log-structured implementation of a RAID subsystem that can be efficiently implemented in software. The methods described in this invention are extraordinarily well suited for software-based RAID 5 systems. In one embodiment, the disk storage subsystems receiving a request to write data. Thereafter, the write operation is appended to a first log to identify a storage location of data written to the disk subsystem, wherein the first log consists of a sequence of segments, the segments consist of a sequence of variable length stripes, a length of a stripe varies based on a quantity of disks addressed by a stripe. In response to adding a disk to the disk storage subsystem, increasing a length of the stripes and increasing a number of disks available for striping data. Alternatively, in response to a disk failing within the disk storage subsystem or a disk being removed from the disk storage system, narrowing a length of the stripes.

Abstract: This invention describes a high-performance, log-structured implementation of a RAID subsystem that can be efficiently implemented in software. The methods described here allow the RAID subsystem to achieve high performance without using specialized hardware such as non-volatile memory or hardware XOR/DMA engines. Furthermore, the RAID implementation described here is well suited for supporting many functions required for advanced storage virtualization such as virtual disks, graceful addition and removal of disks, tolerating multi-disk failures, and snapshots.

Abstract: This invention describes a high-performance, log-structured implementation of a RAID subsystem that can be efficiently implemented in software. The methods described here allow the RAID subsystem to achieve high performance without using specialized hardware such as non-volatile memory or hardware XOR/DMA engines. Furthermore, the RAID implementation described here is well suited for supporting many functions required for advanced storage virtualization such as virtual disks, graceful addition and removal of disks, tolerating multi-disk failures, and snapshots.

Abstract: This invention describes a high-performance, log-structured implementation of a RAID subsystem that can be efficiently implemented in software. The methods described in this invention are extraordinarily well suited for software-based RAID 5 systems. In one embodiment, the disk storage subsystems receiving a request to write data. Thereafter, the write operation is appended to a first log to identify a storage location of data written to the disk subsystem, wherein the first log consists of a sequence of segments, the segments consist of a sequence of variable length stripes, a length of a stripe varies based on a quantity of disks addressed by a stripe. In response to adding a disk to the disk storage subsystem, increasing a length of the stripes and increasing a number of disks available for striping data. Alternatively, in response to a disk failing within the disk storage subsystem or a disk being removed from the disk storage system, narrowing a length of the stripes.

Abstract: A method for efficiently utilizing write-back caches in disk drives to build inexpensive, high-performance, reliable disk arrays. In particular, we describe a method for preserving the ordering of writes issued to a disk array consisting of disks that support write-back caching, without requiring the frequent flushing of the write-back cache.

Abstract: A system and method for facilitating configuration of client stations in a computer network. A virtual disk representing configuration information is formed and selectively exported via the network to the client stations. The stations are configured with the configuration information identified by the virtual disk. Snapshot disks representing modifications to the configuration information required at the client stations can also be created, transported across the computer network, and used to upgrade client station.