Abstract: In a multi-tiered system, a read temperature classification and write temperature classification per virtual block (VLB) can be determined based on the content referenced by each VLB. The temperature classifications of VLBs can be determined using temperature scales which map read and write activity levels to corresponding temperature classifications. The temperature scales can have classification boundaries adjusted based on feedback of operations performed including down-tiering, garbage collection, and compaction and appending. In one use case, a number of free blocks in a high-performance first tier can be below a minimum and processing can be performed to locate a source block of the first tier partially filled with hot content, store the hot content contiguously on a target block of the first tier, flush write data from a log, and store the write data on the target block by appending the write data to the existing hot content.

Abstract: In a multi-tiered system, read temperature and write temperature per virtual block (VLB) can be determined based on the content referenced by each VLB. The read temperature can describe VLB read activity relative to the recency and frequency of read misses of content referenced by the VLB. The write temperature can describe VLB write activity relative to the recency and frequency of overwrites with respect to content referenced by the VLB. Read misses and overwrites can be recorded per processing core in an active tablet used for recording by only a single core. Active and analytic tablet sets across cores can be switched based on criteria. Analytic tablets can be processed and used to update metrics, including read and write temperatures, stored for VLBs. The metrics can be used to determine temperature classifications of VLBs. Content referenced by VLBs can be promoted and/or demoted using VLB temperature classifications.

Abstract: A method, computer program product, and computing system for receiving a plurality of physical layer blocks (PLBs). A subset of PLBs may be selected from the plurality of PLBs for combining into a combined PLB based upon, at least in part, a utilization of each PLB of the plurality of PLBs, an average compression per active virtual, and a number of free PLBs generated when combining into the combined PLB. One or more PLBs of the subset of PLBs may be compressed based upon, at least in part, the average compression per active virtual. The one or more PLBs of the subset of PLBs may be combined into the combined PLB.

Abstract: A method, computer program product, and computing system for identifying a first memory device source that includes first content; identifying a second memory device source that include second content; and initiating a first iteration of a memory device cleansing procedure wherein first content and at least a first portion of the second content are moved to a first unused memory device.

Abstract: A technique for managing a metadata transaction log consolidates multiple mapping pointer changes that affect a single metadata block in a single transaction entry. The technique creates a data structure that identifies the mapping pointers in the metadata block that are changing, and stores the data structure in the transaction entry along with records that describe the individual mapping pointer changes.

Abstract: A method, computer program product, and computing system for maintaining a first cursor pointer for a memory system, wherein the first cursor pointer concerns a first search criteria and identifies an initial first cursor starting location; receiving a first search request for the memory system that satisfies the first search criteria; executing the first search request within an initial first search window starting at the initial first cursor starting location; and updating the first cursor pointer to identify an updated first cursor starting location based, at least in part, upon the initial first search window.

Abstract: A method is used in managing deduplication characteristics in a storage system. Deduplication entries stored in a deduplication cache are categorized into a set of deduplication groups based on a data deduplication probability associated with the deduplication entries. A machine learning system is used to dynamically adjust deduplication characteristics associated with the set of deduplication groups based on an I/O workload associated with the storage system.

Abstract: Techniques are directed to managing Redundant Array of Independent Disks (RAID) storage space. One technique involves providing, by RAID circuitry, a storage space request to mapper circuitry; receiving, by the RAID circuitry, a storage space reply from the mapper circuitry in response to the storage space request; and performing, by the RAID circuitry, a follow-up operation based on the storage space reply from the mapper circuitry. Another technique involves, receiving, by mapper circuitry, a storage space request from RAID circuitry; performing, by the mapper circuitry, a storage space management operation in response to the storage space request; and providing, by the mapper circuitry, a storage space reply to the RAID circuitry, the storage space reply identifying a result of the storage space management operation.

Abstract: A method, computer program product, and computing system for identifying a first memory device source that includes first content; identifying a second memory device source that include second content; and initiating a first iteration of a memory device cleansing procedure wherein first content and at least a first portion of the second content are moved to a first unused memory device.

Abstract: A method, computer program product, and computing system for defining a quantity of discrete storage portions within a storage system; entering an expansion mode during which the discrete storage portions are incrementally assigned to at least one processing node until a first assignment level target is achieved; once the first assignment level target is achieved, entering a utilization mode during which the utilization of the assigned discrete portions is increased until a first utilization level target is achieved; and once the first utilization level target is achieved, reentering the expansion mode during which additional discrete storage portions are incrementally assigned to the at least one processing node until a second assignment level target is achieved.

Abstract: Coordinating a reclaiming of data storage space among processing nodes of a data storage system includes, by a first node in response to an event, performing local cleanup of first-node mapping data and issuing a request message to a second node, the request message identifying the data storage space to be reclaimed. The event may be a notification from a RAID component rebuilding a RAID volume. In response to the request message, the second node performs local cleanup of second-node mapping data and issues a completion message to the first node indicating that the second node has completed its part of the reclaiming of the data storage space. The first node responds to the completion message by marking the data storage space as being reclaimed and signaling to a source of the event that the data storage space is available for new use.

Abstract: A method is used in managing inline data compression in storage systems. A request is received to flush data of a file system to a storage device of a storage system. A compression ratio is determined for writing the data to the storage device in a compressed format. Based on the determination, a number of allocation units is determined in which a segment is apportioned. The segment comprises of a set of allocation units in the compressed format. Based on the determination, the data is written to the segment in the compressed format.

Abstract: A technique for managing write requests in a data storage system checks whether newly-arriving data match previously-stored data that have been recorded in a deduplication database. If a match is found, the technique compares mapping metadata for the newly-arriving data with mapping metadata for the matching data. If both sets of metadata point to the same storage location, then the newly-arriving data is a same-data write and a new write to disk is avoided.

Abstract: An allocation history is maintained for each node in a multi-node data storage system. The allocation history for each node indicates sets of physical blocks previously allocated to the node to store dirty pages of user data flushed from a cache of the node. The allocation history indicates non-quarantined sets of physical blocks that are currently being used to provide non-volatile data storage to cache flush operations, and quarantined sets of physical blocks not currently being used to provide non-volatile data storage to cache flush operations. Allocation is prevented to any node of any set of physical blocks that is indicated as non-quarantined by any of the allocation histories, and of any set of physical blocks that is indicated as quarantined by any of the allocation histories.

Abstract: A data storage system performs updating of a set of global counters stored in persistent storage accessible to a plurality of processing nodes of a data storage system, the global counters storing respective global count values describing associated units of data storage shared by the processing nodes for performing data storage operations. The updating includes, by each processing node, using a respective set of in-memory delta counters storing respective delta count values to track changes to respective global count values due to data storage operations performed by the processing node with respect to the units of data storage. A summarization process is regularly executed to merge the delta count values of the delta counters of all processing nodes into the respective global counters.

Abstract: Techniques for updating persistent statistics on a multi-transactional and multi-node storage system. The techniques can be practiced in a distributed storage system including a plurality of storage nodes. Each storage node can include a persistent storage configured to accommodate a set of delta counter pages, as well as a global counter page for summarizing delta count values tracked by respective delta counters. The techniques can include, in each storage node, tracking, by each of a set of delta counters, changes to delta count values due to storage node operations performed on units of data storage, and summarizing, periodically or at least at intervals, the delta count values of the respective delta counters as global count values. The techniques can further include summarizing the global count values across the respective storage nodes in a count summarization report and sending the count summarization report to a client via a communications interface.

Abstract: Techniques are directed to managing Redundant Array of Independent Disks (RAID) storage space. One technique involves providing, by RAID circuitry, a storage space request to mapper circuitry; receiving, by the RAID circuitry, a storage space reply from the mapper circuitry in response to the storage space request; and performing, by the RAID circuitry, a follow-up operation based on the storage space reply from the mapper circuitry. Another technique involves, receiving, by mapper circuitry, a storage space request from RAID circuitry; performing, by the mapper circuitry, a storage space management operation in response to the storage space request; and providing, by the mapper circuitry, a storage space reply to the RAID circuitry, the storage space reply identifying a result of the storage space management operation.

Abstract: A technique for managing storage of compressed data includes generating and enforcing a minimum slot size requirement. The minimum slot size is based at least in part on collected performance metrics that indicate a degree of compressibility of data received, compressed, and written by the data storage system. As new data arrive, the new data are compressed and stored in slots at least as big as the minimum slot size, in many cases effecting an over-allocation of storage space and improving the likelihood that subsequent overwrites will fit into existing slots.

Abstract: A method, computer program product, and computing system for maintaining a first cursor pointer for a memory system, wherein the first cursor pointer concerns a first search criteria and identifies an initial first cursor starting location; receiving a first search request for the memory system that satisfies the first search criteria; executing the first search request within an initial first search window starting at the initial first cursor starting location; and updating the first cursor pointer to identify an updated first cursor starting location based, at least in part, upon the initial first search window.

Abstract: Coordinating a reclaiming of data storage space among processing nodes of a data storage system includes, by a first node in response to an event, performing local cleanup of first-node mapping data and issuing a request message to a second node, the request message identifying the data storage space to be reclaimed. The event may be a notification from a RAID component rebuilding a RAID volume. In response to the request message, the second node performs local cleanup of second-node mapping data and issues a completion message to the first node indicating that the second node has completed its part of the reclaiming of the data storage space. The first node responds to the completion message by marking the data storage space as being reclaimed and signaling to a source of the event that the data storage space is available for new use.