A memory controller for controlling a memory operation of a memory device includes: an error correction code (ECC) circuit configured to detect an error of first read data read from the memory device and correct the error; an error type detection logic configured to write first write data to the memory device, compare second read data with the first write data, detect an error bit of the second read data based on a result of the comparing, and output information about an error type identified by the error bit; and a data patterning logic configured to change a bit pattern of input data to reduce an error of the second read data based on the information about the error type.

Various embodiments relate to a memory controller, including: a memory interface connected to a memory; an address and command logic connected to the memory interface and a command interface, wherein the address and control logic is configured to receive a memory read request; a memory scrubber configured to cycle through memory locations and to read data from those locations; a region selector configured to determine when a memory location read by the memory scrubber is within an integrity checked memory region; a runtime integrity check (RTIC) engine connected to a read data path of the memory interface, wherein the RTIC engine is configured to calculate an integrity check value for the RTIC region using data read from the checked memory region by the memory scrubber; and a RTIC controller configured to compare the calculated integrity check value for the checked memory region to a reference integrity check value for the checked memory region.

A storage system has a plurality of storage nodes having equal non-volatile storage capacity that is subdivided into equal size cells. Host application data that is stored in the cells is protected using RAID or EC protection groups each having members stored in ones of the cells and distributed across the storage nodes such that no more than one member of any single protection group is stored by any one of the storage nodes. Spare cells are maintained for rebuilding protection group members of a failed one of the storage nodes on remaining non-failed storage nodes so full data access is possible before replacement or repair of the failed storage node.

A system and method for offset protection data in a RAID array. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array is configured to store user data in a first page of a first storage device of the plurality of storage devices; generate intra-device protection data corresponding to the user data, and store the intra-device protection data at a first offset within the first page. The controller is further configured to generate inter-device protection data corresponding to the first page, and store the inter-device protection data at a second offset within a second page in a second storage device of the plurality of storage devices, wherein the first offset is different from the second offset.

Hierarchical coding architectures and schemes based on multistage concatenated codes are described. For instance, multiple encoder and decoder hierarchies may be implemented along with use of corresponding stages of concatenated codes. The coding scheme generally includes an inner coding scheme (e.g., a polar coding scheme, such as a hybrid polar code or Bose Chaudhuri and Hocquenghem (BCH) code), an outer coding scheme (e.g., a Reed-Solomon (RS) coding scheme), and one or more middle coding schemes. The inner coding scheme is based on a polarization transformation (e.g., polar codes with cyclic redundancy check (CRC) codes, polar codes with dynamic freezing codes, polarization-adjusted convolutional (PAC) codes, etc.) which allows for embedding parity data from an outer code inside a codeword along with the user data. The outer coding scheme has a similar concatenated structure (e.g., of an inner RS code with an outer RS code).

A method for rebuilding data, comprising: obtaining, from a metadata node, a source file data layout for a source file and a target file data layout for a target file, wherein the source file is associated with a degraded mapped RAID group and the target file is associated with a new mapped RAID group; generating, by the client application node, a plurality of input/output (I/O) requests to read a portion of the data associated with the source file using the source file data layout; obtaining, in response to the plurality of I/O requests, the portion of the data associated with the source file; rebuilding a second portion of the data associated with source file using the portion of the data; and initiating, storage of at least the second portion of the data associated with the source file in the storage pool using the target file data layout.

Technologies are provided to ensure integrity of erasure coded data that is subject to read and write access from distributed processes. Multiple processes that access erasure coded data can be coordinated in an efficient, scalable and fault-tolerant manner so that integrity of the original data is maintained. The Technologies include a fault-tolerant access coordination protocol that ensures exclusive write access by a client. The coordination protocol achieves scalability by not relying on centralized components, and achieves efficiency and performance by piggy-packing access coordination messages on operations of the underlying erasure coding protocol.

In a method disclosed for writing data, a device receives data, divides the data into one or more data fragments, obtains a first parity fragment based on the one or more data fragments and a second parity fragment of a written data fragment in a stripe distributed across a plurality of nodes, stores the one or more data fragments and the first parity fragment in the stripe.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 16200 and a code rate of 3/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for quadrature phase shift keying (QPSK) modulation.

A method for execution by a dispersed storage network (DSN) managing unit includes receiving access information from a plurality of distributed storage and task (DST) processing units via a network. Cache memory utilization data is generated based on the access information. Configuration instructions are generated for transmission via the network to the plurality of DST processing units based on the cache memory utilization data.