Abstract: A flash-optimized, log-structured layer of a file system of a storage input/output (I/O) stack executes on one or more nodes of a cluster. The log-structured layer of the file system provides sequential storage of data and metadata (i.e., a log-structured layout) on solid state drives (SSDs) of storage arrays in the cluster to reduce write amplification, while leveraging variable compression and variable length data features of the storage I/O stack. The data may be organized as an arbitrary number of variable-length extents of one or more host-visible logical units (LUNs) served by the nodes. The metadata may include mappings from host-visible logical block address ranges (i.e., offset ranges) of a LUN to extent keys, as well as mappings of the extent keys to SSD storage locations of the extents. The storage location of an extent on SSD is effectively “virtualized” by its mapped extent key (i.e.

Abstract: Embodiments described herein provide an object store that efficiently manages and services objects for use by clients of a distributed data processing system. Illustratively, the object store may be embodied as a quasi-shared storage system that interacts with nodes of the distributed data processing system to service the objects as blocks of data stored on a plurality of storage devices, such as disks, of the storage system. To that end, an architecture of the object store may include an on-disk layout, e.g., of the storage system, and an incore layout, e.g., of the nodes, that cooperate to illustratively convert the blocks to objects for access by the clients.

Abstract: A flash-optimized, log-structured layer of a file system of a storage input/output (I/O) stack executes on one or more nodes of a cluster. The log-structured layer of the file system provides sequential storage of data and metadata (i.e., a log-structured layout) on solid state drives (SSDs) of storage arrays in the cluster to reduce write amplification, while leveraging variable compression and variable length data features of the storage I/O stack. The data may be organized as an arbitrary number of variable-length extents of one or more host-visible logical units (LUNs) served by the nodes. The metadata may include mappings from host-visible logical block address ranges (i.e., offset ranges) of a LUN to extent keys, as well as mappings of the extent keys to SSD storage locations of the extents. The storage location of an extent on SSD is effectively “virtualized” by its mapped extent key (i.e.

Abstract: In one embodiment, storage arrays of solid state drives (SSDs) coupled to a node are organized as redundant array of independent disks (RAID) groups. Each storage array includes one or more segments. Each segment has contiguous free space on the SSDs. Data and metadata is organized on the SSDs with a sequential log-structured layout, with the data organized as variable-length extents of one or more logical units (LUNs). Segment cleaning is performed to clean a selected segment by moving the extents of the selected segment that contain valid data to one or more different segments so as to free the selected segment. Additional extents are written as a sequence of contiguous range write operations to the entire free segment with temporal locality to reduce data relocation within the SSDs as a result of the write operations.

Abstract: Embodiments described herein provide an object store that efficiently manages and services objects for use by clients of a distributed data processing system. Illustratively, the object store may be embodied as a quasi-shared storage system that interacts with nodes of the distributed data processing system to service the objects as blocks of data stored on a plurality of storage devices, such as disks, of the storage system. To that end, an architecture of the object store may include an on-disk layout, e.g., of the storage system, and an incore layout, e.g., of the nodes, that cooperate to illustratively convert the blocks to objects for access by the clients.

Abstract: A storage architecture of a storage system environment has a storage connector interface configured to exchange data directly between flash storage devices on a server and a storage array of the environment so as to bypass main memory and a system bus of the server. According to one or more embodiments, the storage connnector interface includes control logic configured to implement the data exchange in accordance with one of a plurality of operational modes that deploy and synchronize the data on the flash storage devices and the storage array. Advantageously, the storage connector interface obviates latencies and bandwidth consumption associated with prior data exchanges over the main memory and bus, thereby enhancing storage architecture performance.

Abstract: In one embodiment, storage arrays of solid state drives (SSDs) coupled to a node are organized as redundant array of independent disks (RAID) groups. Each storage array includes one or more segments. Each segment has contiguous free space on the SSDs. Data and metadata is organized on the SSDs with a sequential log-structured layout, with the data organized as variable-length extents of one or more logical units (LUNs). Segment cleaning is performed to clean a selected segment by moving the extents of the selected segment that contain valid data to one or more different segments so as to free the selected segment. Additional extents are written as a sequence of contiguous range write operations to the entire free segment with temporal locality to reduce data relocation within the SSDs as a result of the write operations.

Abstract: An extent-based storage architecture is implemented by a storage server receiving a read request for an extent from a client, wherein the extent includes a group of contiguous blocks and the read request includes a file block number. The storage server retrieves an extent identifier from a first sorted data structure, wherein the storage server uses the received file block number to traverse the first sorted data structure to the extent identifier. The storage server retrieves a reference to the extent from a second sorted data structure, wherein the storage server uses the retrieved extent identifier to traverse the second sorted data structure to the reference, and wherein the second sorted data structure is global across a plurality of volumes. The storage server retrieves the extent from a storage device using the reference and returns the extent to the client.

Abstract: In one embodiment, a flash-optimized, log-structured layer of a file system of a storage input/output (I/O) stack executes on one or more nodes of a cluster. The log-structured layer of the file system provides sequential storage of data and metadata on solid state drives (SSDs) to reduce write amplification, while leveraging variable compression and variable length data features of the storage I/O stack. The data may be organized as an arbitrary number of variable-length extents of one or more host-visible logical units (LUNs). The metadata may include mappings from host-visible logical block address ranges of a LUN to extent keys, as well as mappings of the extent keys to SSD storage locations of the extents. The storage location of an extent on SSD is effectively “virtualized” by its mapped extent key such that relocation of the extent on SSD does not require update to volume layer metadata.

Abstract: A storage architecture of a storage system environment has a storage connector interface configured to exchange data directly between flash storage devices on a server and a storage array of the environment so as to bypass main memory and a system bus of the server. According to one or more embodiments, the storage connnector interface includes control logic configured to implement the data exchange in accordance with one of a plurality of operational modes that deploy and synchronize the data on the flash storage devices and the storage array. Advantageously, the storage connector interface obviates latencies and bandwidth consumption associated with prior data exchanges over the main memory and bus, thereby enhancing storage architecture performance.

Abstract: A method and system performs a fencing technique in a host cluster storage environment. The fence program executes on each cluster member in the cluster, and the cluster is coupled to a storage system by a network. When a cluster member fails or cluster membership changes, the fence program is invoked and a host fencing API message is sent via the network to the storage system. The storage system in turn modifies export lists to restrict further access by the failed cluster node to otherwise fence the failed cluster node off from that storage system or from certain directories within that storage system.

Abstract: A method and system performs fencing techniques in a host cluster storage environment. A fencing application program interface resides in one or more storage systems. When a message is received by said storage system from a cluster member, the storage system in turn modifies the NFS export lists of one or more storage systems to restrict further access by the failed cluster node to otherwise fence the failed cluster node off from that storage system or from certain directories within that storage system. Prior to said access permission rights being changed, NFS operations are locked and drained, NFS locks are removed after which the export lists are modified. Once the fencing operations are performed, the NFS operations are served again by the storage system.

Abstract: A method and system performs a fencing technique in a host cluster storage environment. The fence program executes on each cluster member in the cluster, and the cluster is coupled to a storage system by a network. When a cluster member fails or cluster membership changes, the fence program is invoked and a host fencing API message is sent via the network to the storage system. The storage system in turn modifies export lists to restrict further access by the failed cluster node to otherwise fence the failed cluster node off from that storage system or from certain directories within that storage system.

Abstract: A host-clustered networked storage environment includes a “quorum program.” The quorum program is invoked when a change in cluster membership occurs, or when the cluster members are not receiving reliable information about the continued viability of the cluster, or for a variety of other reasons. When the quorum program is so invoked, the cluster member is programmed to assert a claim on a quorum device configured in accordance with the present invention. More specifically, the quorum device is a vdisk embodied in as a logical unit (LUN) exported by the networked storage system. The LUN is created as a quorum device upon which a SCSI-3 reservation can be placed by an initiator. Thus, the LUN is created for this purpose as a SCSI target that exists solely as a quorum device. Fencing techniques are also provided in the networked environment such that failed cluster members can be fenced from given—exports of the networked—storage system.

Abstract: The present invention provides an improved method and system for real-time monitoring, validation, optimization and predictive fault analysis in a process control system. The invention monitors process operations by continuously analyzing sensor measurements and providing predictive alarms using models of normal process operation and statistical parameters corresponding to normal process data, and generating secondary residual process models. The invention allows for the creation of a fault analyzer directly from linearly independent models of normal process operation, and provides for automatic generation from such process models of linearly dependent process models. Fuzzy logic is used in various fault situations to compute certainty factors to identify faults and/or validate underlying assumptions.

Abstract: A computer system for managing a computer network comprises a rack cabinet having a cabinet interior. A plurality of infrastructure connector assemblies are fixedly mounted on the rack cabinet in 1-U boundaries, each infrastructure connector assembly including a signal snap interface connector and a power snap interface connector. A plurality of compute elements are adapted to be slidably disposed within the cabinet interior of the rack cabinet in a stacked relationship, each compute element including at least one infrastructure connector assembly which releasably snap-interconnects with an associated infrastructure connector assembly mounted on the rack cabinet. A distributed power bay is disposed within the rack cabinet and provides central power for the computer system. A rack manager is disposed within the rack cabinet and includes the central video and I/O devices for the computer system.