Abstract: Apparatuses, systems, methods, and computer program products are disclosed. A method includes tracking which portions of data stored in a volatile memory buffer are not yet stored in a non-volatile memory medium. A volatile memory buffer may be accessible using memory semantics. A volatile memory buffer may be associated with logic configured to ensure that the data stored in the volatile memory buffer is non-volatile. A method includes maintaining consistency of data between a volatile memory buffer and a non-volatile memory medium based on tracked portions of the data. A method includes copying at least portions of data not yet stored in a non-volatile memory medium to the non-volatile memory medium in response to a trigger.

Abstract: A storage controller is configured to implement an atomic storage operation comprising a plurality of separate storage operations on a non-volatile storage medium. The storage controller may store persistent indicators to identify data that pertains to the atomic storage operation. An invalid shutdown may occur before the atomic storage operation is complete. A restart and recovery operation comprises a first scan of the non-volatile storage medium to identify data of the failed atomic storage operation. A physical trim note is stored on the non-volatile storage medium to identify the data of the failed atomic storage operation. The data may be identified by media address. Storage metadata is reconstructed in a second scan, which excludes the data and/or operations of the failed atomic storage operation.

Abstract: Apparatuses, systems, methods, and computer program products are disclosed for hybrid checkpointed memory. A method includes referencing data of a range of virtual memory of a host. The referenced data is already stored by a non-volatile medium. A method includes writing, to a non-volatile medium, data of a range of virtual memory that is not stored by the non-volatile medium. A method includes providing access to data of a range of virtual memory from a non-volatile medium using a persistent identifier associated with referenced data and written data.

Abstract: Apparatuses, systems, and methods are disclosed for a key-value store. A method includes encoding a key of a key-value pair into a logical address of a sparse logical address space for a non-volatile medium. A method includes mapping a logical address to a physical location in the non-volatile medium. A method includes storing a value of a key-value pair at a physical location.

Abstract: Apparatuses, systems, and methods are disclosed for data expiry. A method includes examining metadata associated with data in a non-volatile recording medium. A method includes expiring data from a non-volatile recording medium in response to metadata indicating that an expiration period for the data has been satisfied.

Abstract: A multi-tiered cache manager and methods for managing multi-tiered cache are described. Multi-tiered cache manager causes cached data to be initially stored in the RAM elements and selects portions of the cached data stored in the RAM elements to be moved to the flash elements. Each flash element is organized as a plurality of write blocks having a block size and wherein a predefined maximum number of writes is permitted to each write block. The portions of the cached data may be selected based on a maximum write rate calculated from the maximum number of writes allowed for the flash device and a specified lifetime of the cache system.

Abstract: An apparatus, system, and method are disclosed for managing a cache. A cache interface module provides access to a plurality of virtual storage units of a solid-state storage device over a cache interface. At least one of the virtual storage units comprises a cache unit. A cache command module exchanges cache management information for the at least one cache unit with one or more cache clients over the cache interface. A cache management module manages the at least one cache unit based on the cache management information exchanged with the one or more cache clients.

Abstract: A cache module leverages storage metadata to cache data of a backing store on a non-volatile storage device. The cache module maintains access metadata pertaining to access characteristics of logical identifiers in the logical address space, including access characteristics of un-cached logical identifiers (e.g., logical identifiers associated with data that is not stored on the non-volatile storage device). The access metadata may be separate and/or distinct from the storage metadata. The cache module determines whether to admit data into the cache and/or evict data from the cache using the access metadata. A storage module may provide eviction candidates to the cache module. The cache module may select candidates for eviction. The storage module may leverage the eviction candidates to improve the performance of storage recovery and/or grooming operations.

Abstract: A cache layer leverages a logical address space and storage metadata of a storage layer (e.g., virtual storage layer) to cache data of a backing store. The cache layer maintains access metadata to track data characteristics of logical identifiers in the logical address space, including accesses pertaining to data that is not in the cache. The access metadata may be separate and distinct from the storage metadata maintained by the storage layer. The cache layer determines whether to admit data into the cache using the access metadata. Data may be admitted into the cache when the data satisfies cache admission criteria, which may include an access threshold and/or a sequentiality metric. Time-ordered history of the access metadata is used to identify important/useful blocks in the logical address space of the backing store that would be beneficial to cache.

Abstract: A cache module leverages a logical address space and storage metadata of a storage module (e.g., virtual storage module) to cache data of a backing store. The cache module maintains access metadata to track access characteristics of logical identifiers in the logical address space, including accesses pertaining to data that is not currently in the cache. The access metadata may be separate from the storage metadata maintained by the storage module. The cache module may calculate a performance metric of the cache based on profiling metadata, which may include portions of the access metadata. The cache module may determine predictive performance metrics of different cache configurations. An optimal cache configuration may be identified based on the predictive performance metrics.

Abstract: A method and apparatus for storing data packets in two different logical erase blocks pursuant to an atomic storage request is disclosed. Each data packet stored in response to the atomic storage request comprises persistent metadata indicating that the data packet pertains to an atomic storage request. In addition, a method and apparatus for restart recovery is disclosed. A data packet preceding an append point is identified as satisfying a failed atomic write criteria, indicating that the data packet pertains to a failed atomic storage request. One or more data packets associated with the failed atomic storage request are identified and excluded from an index of a non-volatile storage media.

Abstract: Data of a vector storage request pertaining to one or more disjoint, non-adjacent, and/or non-contiguous logical identifier ranges are stored contiguously within a log on a non-volatile storage medium. A request consolidation module modifies one or more sub-requests of the vector storage request in response to other, cached storage requests. Data of an atomic vector storage request may comprise persistent indicators, such as persistent metadata flags, to identify data pertaining to incomplete atomic storage requests. A restart recovery module identifies and excludes data of incomplete atomic operations.

Abstract: A multi-tiered cache manager and methods for managing multi-tiered cache are described. Multi-tiered cache manager causes cached data to be initially stored in the RAM elements and selects portions of the cached data stored in the RAM elements to be moved to the flash elements. Each flash element is organized as a plurality of write blocks having a block size and wherein a predefined maximum number of writes is permitted to each write block. The portions of the cached data may be selected based on a maximum write rate calculated from the maximum number of writes allowed for the flash device and a specified lifetime of the cache system.

Abstract: An apparatus, system, and method are disclosed for managing storage capacity recovery. A monitor module determines a workload write bandwidth for a sequential log-based data storage device. The workload write bandwidth includes a rate at which workload write operations generate reclaimable storage capacity on the data storage device. A target module determines a target reclamation write bandwidth for the data storage device. A capacity reclaim rate is associated with the target reclamation write bandwidth. The capacity reclaim rate satisfies the workload write bandwidth for the data storage device. A reclaim rate module determines a prospective reclamation write bandwidth for the data storage device, based on the workload write bandwidth, to correspond to the capacity reclaim rate associated with the target reclamation write bandwidth.

Abstract: A multi-tiered cache manager and methods for managing multi-tiered cache are described. Multi-tiered cache manager causes cached data to be initially stored in the RAM elements and selects portions of the cached data stored in the RAM elements to be moved to the flash elements. Each flash element is organized as a plurality of write blocks having a block size and wherein a predefined maximum number of writes is permitted to each write block. The portions of the cached data may be selected based on a maximum write rate calculated from the maximum number of writes allowed for the flash device and a specified lifetime of the cache system.

Abstract: A method for efficient communications with a cluster-based architecture preserves various aspects of integrity throughout one or more connections with a client, even in the midst of connection migration between nodes in the cluster. According to one aspect, the invention provides a mechanism for preventing the loss of packets arising from a TCP connection migration within the cluster. According to another aspect, the invention provides a mechanism for uniquely identifying conflicting TCP connections migrated to a common node. According to a still further aspect, the invention provides a distributed TCP timestamp mechanism so that the sender and receiver will have a consistent view of the timestamp even when each node has different local clock values and regardless of how many times the socket has been migrated.

Abstract: The present invention relates generally to a method for efficient I/O handling in a cluster-based architecture. According to one aspect, the invention enables efficient scheduling of TCP connection migrations within a cluster. According to another aspect, the invention enables I/Os performed as TCP handoff operations to coexist on the same TCP/IP connection with I/Os performed as remote operations.

Abstract: The present invention relates generally to a method for efficient I/O handling in a cluster-based architecture. According to one aspect, the invention enables efficient scheduling of TCP connection migrations within a cluster. According to another aspect, the invention enables I/Os performed as TCP handoff operations to coexist on the same TCP/IP connection with I/Os performed as remote operations.

Abstract: Systems and methods for routing messages in an interconnection fabric are provided. The fabric includes a plurality of nodes, each node having, for example, four ports coupled to adjacent nodes in the fabric. A source node initiating a message in the fabric can transmit the message out of one of its four ports. Between a source node and a destination node, there are at least four independent paths which may be taken, depending on the output port from the source node. However, the precise path is not expressly delineated in the message. Instead, the message contains the address of the destination node, the address of the originating node, and a target region for the message. Each intermediate node is configured to receive a message via one of its four ports, and then select an appropriate output port based on the location of the port which received the message combined with the address and target information contained in the message.

Abstract: A data layout mechanism is described for allocating metadata within a storage system employing data striping. The data layout mechanism includes a number of storage devices, each of the storage devices having storage spaces allocated to store individual data stripe units associated with a number of stripes. The data layout mechanism further includes a plurality of metadata chunks allocated within the storage devices such that (1) metadata associated with at least two data stripe units of the same stripe is stored within a single metadata chunk, and (2) the metadata chunks are evenly distributed across the storage devices.