Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. A plurality of failure resilient address spaces are distributed across the plurality of storage devices such that each of the plurality of failure resilient address spaces spans a plurality of the storage devices. Each computing device is operable to maintain a two-level registry that records changes in the memory. When data is read from memory, recent changes to the data may be applied according to one or more corresponding registry blocks. Thus, the two-level registry enables the plurality of computing devices to postpone and/or consolidate writes to memory (e.g., non-volatile flash drives).

Abstract: A system comprises a plurality of computing devices that are communicatively coupled via a network and have a file system distributed among them, and comprises one or more file system request buffers residing on one or more of the plurality of computing devices. File system choking management circuitry that resides on one or more of the plurality of computing devices is operable to separately control: a first rate at which a first type of file system requests (e.g., one of data requests, data read requests, data write requests, metadata requests, metadata read requests, and metadata write requests) are fetched from the one or more buffers, and a second rate at which a second type of file system requests (e.g., another of data requests, data read requests, data write requests, metadata requests, metadata read requests, and metadata write requests) are fetched from the one or more buffers.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. One or more of the computing devices and/or the storage devices may be used to rebuild data that may be lost due to a power failure.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. Each computing device is operable to access one or more memory blocks within the storage devices and maintain a registry over the same one or more memory blocks. The registry may be adaptively resized according to the access of the one or more memory blocks.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. Data communication is made more efficient by removing the need to copy data in the networking stack, using hardware accelerated end-to-end checksum calculation, and supporting transmission formatting of data and header for special cases.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. The storage devices may be assigned to one of a plurality of memory tiers, and the data in a storage device may be reassigned to another storage device in a different memory tier.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. Each computing device is operable to compress one or more blocks of data and append a journal in front of the data. The journal and the data are written concurrently to flash memory. Each computing device is also operable to maintain a metadata registry that records changes in the flash memory. In the event of a power failure, the journal and previous journals may be used to verify the state of the metadata registry.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. A plurality of failure resilient address spaces are distributed across the plurality of storage devices such that each of the plurality of failure resilient address spaces spans a plurality of the storage devices. The plurality of computing devices maintains metadata that maps each failure resilient address space to one of the plurality of computing devices. Each of the plurality of computing devices is operable to read from and write to a plurality of memory blocks, while maintaining an extent in metadata that maps the plurality of memory blocks to the failure resilient address space.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more flash storage devices. Each computing device is operable to access one or more memory blocks within the flash storage devices and maintain a directory structure for managing access to the memory. The directory structure may be adaptively resized according to the addition or removal of one or more associated files stored in memory.

Abstract: Methods and systems are provided for rapid failure recovery for a distributed storage system for failures by one or more nodes.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. A plurality of failure resilient address spaces are distributed across the plurality of storage devices such that each of the plurality of failure resilient address spaces spans a plurality of the storage devices. Each computing device is operable to maintain a two-level registry that records changes in the memory. When data is read from memory, recent changes to the data may be applied according to one or more corresponding registry blocks. Thus, the two-level registry enables the plurality of computing devices to postpone and/or consolidate writes to memory (e.g., non-volatile flash drives).

Abstract: A system comprises a plurality of computing devices that are communicatively coupled via a network and have a file system distributed among them, and comprises one or more file system request buffers residing on one or more of the plurality of computing devices. File system choking management circuitry that resides on one or more of the plurality of computing devices is operable to separately control: a first rate at which a first type of file system requests (e.g., one of data requests, data read requests, data write requests, metadata requests, metadata read requests, and metadata write requests) are fetched from the one or more buffers, and a second rate at which a second type of file system requests (e.g., another of data requests, data read requests, data write requests, metadata requests, metadata read requests, and metadata write requests) are fetched from the one or more buffers.

Abstract: A method for data storage includes defining a host cluster within a group of host computers, which access a storage system that includes multiple logical volumes. The host cluster includes two or more of the host computers. Responsively to a single mapping instruction, each of the host computers in the host cluster is mapped to access the logical volumes in the set. In another disclosed method, a single control instruction, which specifies the host cluster and a configuration operation to be applied to the host computers in the host cluster, is accepted. Responsively to the single control instruction, the configuration operation is applied to each of the host computers in the host cluster. The configuration operation may comprise assigning a specified level of service to each host computer in one of the first subset of the host computers and the second subset of the host computers.

Abstract: One or more computing devices may comprise congestion management circuitry, one or more client file system request buffers, and DESS interface circuitry. The one or more client file system request buffers is/are operable to queue first client file system requests of a first priority level and second client file system requests of a second priority level, where the first priority level is higher priority than the second priority level. The DESS interface circuitry is operable to determine a choking level according to the load on a plurality of DESS resources. Individual load values of the DESS resources are mapped to a composite load value using a first function. The composite load value is mapped to a congestion contribution using a second function. And, the congestion contribution is mapped to a choking level using a third function.

Abstract: A plurality of computing devices are communicatively coupled to each other via a network, and each of the plurality of computing devices is operably coupled to one or more of a plurality of storage devices. A plurality of failure resilient address spaces are distributed across the plurality of storage devices such that each of the plurality of failure resilient address spaces spans a plurality of the storage devices. The plurality of computing devices maintains metadata that maps each failure resilient address space to one of the plurality of computing devices. The metadata is grouped into buckets. Each bucket is stored in a group of computing devices. However, only the leader of the group is able to directly access a particular bucket at any given time.

Abstract: One or more computing devices may comprise congestion management circuitry, one or more client file system request buffers, and DESS interface circuitry. The one or more client file system request buffers is/are operable to queue first client file system requests of a first priority level and second client file system requests of a second priority level, where the first priority level is higher priority than the second priority level. The DESS interface circuitry is operable to determine a choking level according to the load on a plurality of DESS resources. Individual load values of the DESS resources are mapped to a composite load value using a first function. The composite load value is mapped to a congestion contribution using a second function. And, the congestion contribution is mapped to a choking level using a third function.

Abstract: A system comprises a plurality of computing devices that are communicatively coupled via a network and have a file system distributed among them, and comprises one or more file system request buffers residing on one or more of the plurality of computing devices. File system choking management circuitry that resides on one or more of the plurality of computing devices is operable to separately control: a first rate at which a first type of file system requests (e.g., one of data requests, data read requests, data write requests, metadata requests, metadata read requests, and metadata write requests) are fetched from the one or more buffers, and a second rate at which a second type of file system requests (e.g., another of data requests, data read requests, data write requests, metadata requests, metadata read requests, and metadata write requests) are fetched from the one or more buffers.

Abstract: A system comprises control circuitry that is operable to assign a first of a plurality of computing devices to serve file system requests destined for any of a first plurality of network addresses; assign a second of the computing devices to serve file system requests destined for any of a second plurality of network addresses; maintain statistics regarding file system requests sent to each of the first plurality of network addresses and the second plurality of network addresses; and reassign, based on the statistics, the first of the computing devices to serve file system requests destined for a selected one of the second plurality of network addresses.

Abstract: A system comprises a plurality of computing devices that are communicatively coupled via a network and have a file system distributed among them, and comprises one or more file system request buffers residing on one or more of the plurality of computing devices. File system choking management circuitry that resides on one or more of the plurality of computing devices is operable to separately control: a first rate at which a first type of file system requests (e.g., one of data requests, data read requests, data write requests, metadata requests, metadata read requests, and metadata write requests) are fetched from the one or more buffers, and a second rate at which a second type of file system requests (e.g., another of data requests, data read requests, data write requests, metadata requests, metadata read requests, and metadata write requests) are fetched from the one or more buffers.

Abstract: A method for data storage includes defining a host cluster within a group of host computers, which access a storage system that includes multiple logical volumes. The host cluster includes two or more of the host computers. Responsively to a single mapping instruction, each of the host computers in the host cluster is mapped to access the logical volumes in the set. In another disclosed method, a single control instruction, which specifies the host cluster and a configuration operation to be applied to the host computers in the host cluster, is accepted. Responsively to the single control instruction, the configuration operation is applied to each of the host computers in the host cluster. The configuration operation may comprise assigning a specified level of service to each host computer in one of the first subset of the host computers and the second subset of the host computers.