In accordance with embodiments disclosed herein, there are provided methods, systems, mechanisms, techniques, and apparatuses for presentation of direct accessed storage under a logical drive model; for implementing a distributed architecture for cooperative NVM Data protection; data mirroring for consistent SSD latency; for boosting a controller's performance and RAS with DIF support via concurrent RAID processing; for implementing arbitration and resource schemes of a doorbell mechanism, including doorbell arbitration for fairness and prevention of attack congestion; and for implementing multiple interrupt generation using a messaging unit and NTB in a controller through use of an interrupt coalescing scheme.

A method for rebuilding data when changing erase block sizes in a storage system is provided. The method includes determining one or more erase blocks to be rebuilt and allocating one or more replacement erase blocks, wherein the one or more erase blocks and the one or more replacement erase blocks have differing erase block sizes. The method includes mapping logical addresses, for the one or more erase blocks, to the one or more replacement erase blocks and rebuilding the one or more erase blocks into the one or more replacement erase blocks, in accordance with the mapping.

A method, computer program product, and computing system for receiving, at a cache memory system, a write request for writing data to a storage system. A data reduction rate may be predicted for the write request. One or more portions of memory within the storage system may be allocated based upon, at least in part, the predicted data reduction rate for the write request. The write request may be flushed from the cache memory system to the allocated one or more portions of memory within the storage system.

Described are examples for storing, in a first zone cache, one or more logical blocks (LBs) corresponding to a data chunk, writing, for each LB in the data chunk, a cache element of a cache entry that points to the LB in the first zone cache, where the cache entry includes multiple cache elements corresponding to the multiple LBs of the data chunk, writing, for the cache entry, a table entry in a mapping table that points to the cache entry, and when a storage policy is triggered for the cache entry, writing the multiple LBs, pointed to by each cache element of the cache entry, as contiguous LBs in an isolation block for the data chunk in a second zone stream, and updating the table entry to point to the isolation block in the second zone stream.

A storage control system maintains a write cache in a non-volatile memory device of primary memory of a storage node. The write cache comprises a cyclic buffer and pointers to manage the write cache and track a tail location and head location of the write cache. The storage control system receives a write request from a host system, which comprises a data item to be written to primary storage. The received data item is written together with an associated metadata item at the head location of the write cache. The items in the write cache are arranged in a cyclic write order from the tail location to the head location. The storage control system sends an acknowledgment to the host system that the data item is successfully written to the primary storage, in response to the received data item and the associated metadata item being stored in the write cache.

A storage control apparatus comprising: a memory; and a processor coupled to the memory and configured to: receive a release request for a first storage area in a virtual storage area, release, among unit storage areas included in a physical storage area, one or more first unit storage areas allocated to the first storage area from the first storage area, execute overwrite processing of writing 0 to each of the first unit storage areas at a timing asynchronous with the release of the first unit storage areas, and when a write request is received to write data to the virtual storage area, execute write processing in which an unallocated unit storage area among the unit storage areas included in the physical storage area is allocated to a write destination area for the write data in the virtual storage area.

A computer-implemented method, according to one approach, includes: receiving a stream of incoming I/O requests, all of which are satisfied using one or more buffers in a primary cache. However, in response to determining that the available capacity of the one or more buffers in the primary cache is outside a predetermined range: one or more buffers in the secondary cache are allocated. These one or more buffers in the secondary cache are used to satisfy at least some of the incoming I/O requests, while the one or more buffers in the primary cache are used to satisfy a remainder of the incoming I/O requests. Moreover, in response to determining that the available capacity of the one or more buffers in the primary cache is not outside the predetermined range: the one or more buffers in the primary cache are again used to satisfy all of the incoming I/O requests.

A method, computer program product, and computing system for assigning a plurality of unique sequential identifiers to a plurality of tablets in a cache memory system. One or more metadata deltas associated with a metadata page stored in a storage array may be written to the plurality of tablets in the cache memory system. Each metadata delta stored in at least one tablet of the plurality of tablets may be written to the metadata page stored in the storage array, thus defining one or more destage tablets. A largest unique sequential identifier from the plurality of unique sequential identifiers assigned to the one or more destage tablets, may be written to the storage array, thus defining a current tablet identifier for the metadata page.

In various embodiments, a method for page cache management is described. The method can include: identifying a storage device fault associated with a fault-resilient storage device; determining that a first region associated with the fault-resilient storage device comprises an inaccessible space and that a second region associated with the fault-resilient storage device comprises an accessible space; identifying a read command at the second storage device for the data and determine, based on the read command, first data requested by a read operation from a local memory of the second storage device; determining, based on the read command, second data requested by the read operation from the second region; retrieving the second data from the second region; and scheduling a transmission of the second data from the fault-resilient storage device to the second storage device.

A storage control system receives a first write request and a second write request following the first write request. The first and second write requests comprise respective first and second data items for storage to a primary storage. First and second cache write operations are performed in parallel to write the first and second data items a persistent write cache. The first cache write operation comprises a split write operation which comprises writing a parsing header for the first data item to the write cache, and writing a payload of the first data item to the write cache. The second cache write operation comprises storing the second data item and associated metadata in the write cache, and waiting for an acknowledgment that the parsing header for the first data item has been successfully stored in the write cache before returning an acknowledgment indicating successful storage of the second data item.