Abstract: In one embodiment, a computer program product includes a computer readable storage medium having program instructions embodied therewith. The program instructions are executable by a processing circuit to cause the processing circuit to perform a method that includes determining, after writing data to a non-volatile memory block, one or more delta threshold voltage shift (TVS?) values. One or more overall threshold voltage shift values is calculated for the data written to the non-volatile memory block. The one or more overall threshold voltage shift values are stored. The method also includes reading one or more TVS values from a non-volatile controller memory, and resetting a program/erase cycle count since last calibration after calibrating the one or more overall threshold voltage shift values. The one or more TVS? values and the program/erase cycle count since last calibration are stored to the non-volatile controller memory.

Abstract: In at least one embodiment, a non-volatile memory array including a plurality of blocks each including a plurality of physical pages is controlled by a controller. The controller implements a plurality of nested page retirement classes each defined by a respective one of a plurality of different nested subsets of page indices of physical pages within the plurality of blocks that are to be considered retired from use. For each block among the plurality of blocks, the controller updating an indication of a page retirement class to which the block belongs in response to detection of a retirement-causing error in a data page stored in a physical page of the block. The controller forms block stripes for storing data from the plurality of blocks based on the page retirement classes of the blocks.

Abstract: A device for storing data in a plurality of multi-level cell memory chips. The device includes a scrambling unit to generate a plurality of candidate scrambled sequences of data by performing a plurality of scrambling operations on a sequence of data to be stored, a calculation unit to calculate a cost function for each of the plurality of candidate scrambled sequences of data, the result of each cost function being indicative of a balancing degree of subsequences of a candidate scrambled sequence, when the subsequences of the candidate scrambled sequence are written to the plurality of multi-level cell memory chips, a selection unit to select one of the candidate scrambled sequences of data based on the results of the cost functions, and a storing unit to store the selected candidate scrambled sequence of data in the multi-level cell memory chips by storing the subsequences across the multi-level memory chips.

Abstract: A computer-implemented method, according to one embodiment, includes: detecting at least one read of a logical page straddled across codewords, storing an indication of a number of detected reads of the straddled logical page, and relocating the straddled logical page to a different physical location in response to the number of detected reads of the straddled logical page. When relocated, the logical page is written to the different physical location in a non-straddled manner. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: An apparatus, according to one embodiment, includes: one or more memory devices, each memory device comprising non-volatile memory configured to store data, and a memory controller connected to the one or more memory devices. The memory controller is configured to: detect at least one read of a logical page straddled across codewords, store an indication of a number of detected reads of the straddled logical page, and relocate the straddled logical page to a different physical location in response to the number of detected reads of the straddled logical page, wherein the logical page is written to the different physical location in a non-straddled manner. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: In one embodiment, a computer-implemented method includes determining, by a processor, after the writing of data to a non-volatile memory block, one or more delta threshold voltage shift (TVS?) values configured to track temporary changes with respect to changes in the underlying threshold voltage distributions due to retention and/or read disturb errors. One or more overall threshold voltage shift values is calculated for the data written to the non-volatile memory block, the one or more overall threshold voltage shift values being a function of the one or more TVS? values to be used when writing data to the non-volatile memory block. The one or more overall threshold voltage shift values are stored.

Abstract: Techniques for data deduplication in a data storage system include comparing a first attribute of a received data page to first attributes of one or more stored data pages. In response to the first attribute matching one of the first attributes, a second attribute of the received data page is compared to second attributes of the one or more data pages. In response to the second attribute of the received data page matching one of the second attributes, a fingerprint of the received data page is compared to fingerprints of the one or more data pages. In response to the fingerprint of the received data page matching one of the fingerprints, the received data page is discarded and replaced with a reference to the corresponding data page already stored in the storage system. In response to first attribute, the second attribute, or the fingerprint of the received data page not matching, the received data page is stored.

Abstract: In at least one embodiment, a history data structure of a Lempel-Ziv compressor is preloaded with fixed predetermined history data typical of actual data of a workload of the Lempel-Ziv compressor. The Lempel-Ziv compressor then compresses each of multiple data pages in a sequence of data pages by reference to the fixed predetermined history data.

Abstract: A mechanism is provided for high-throughput compression of data. Responsive to receiving an indication of a match of a current 4-byte sequence from an incoming data stream to stored hash values in a set of hash tables, numerous variables are set to initial values. Responsive to receiving a subsequent 4-byte sequence from the incoming data stream and determining that an active match variable is set to one, the subsequent 4-byte sequence is compared to data in a copy of the incoming data stream in memory at an active position with a predefined length offset. A constraint variable is set to a number of bytes for which the match is to be extended. Responsive to the constraint variable being below a predetermined number, a length, distance pair is output indicating a match to a previous pattern in the incoming data stream.

Abstract: Techniques for data deduplication in a data storage system include comparing a first attribute of a received data page to first attributes of one or more stored data pages. In response to the first attribute matching one of the first attributes, a second attribute of the received data page is compared to second attributes of the one or more data pages. In response to the second attribute of the received data page matching one of the second attributes, a fingerprint of the received data page is compared to fingerprints of the one or more data pages. In response to the fingerprint of the received data page matching one of the fingerprints, the received data page is discarded and replaced with a reference to the corresponding data page already stored in the storage system. In response to first attribute, the second attribute, or the fingerprint of the received data page not matching, the received data page is stored.

Abstract: A computer-implemented method, according to one embodiment, includes: repeating the following sequence at least until a page stripe of a memory cache has at least a predetermined amount of data stored therein: finding an open codeword having an amount of available space which is greater than or equal to a size of a compressed logical page, and storing the compressed logical page in the open codeword having the amount of available space which is greater than or equal to a size of the compressed logical page. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: In a data storage system, a prior set S of prefix codes for pseudo-dynamic compression as well as data compressed utilizing prior set S are stored. While data compressed utilizing prior set S are stored in the data storage system, the number of prefix codes utilized by the data storage system for pseudo-dynamic compression are augmented. Augmenting the number of codes includes determining a new set S? of prefix codes for pseudo-dynamic compression from a training data set selected from a workload of the data storage system and storing the new set S? in the data storage system with the prior set S.

Abstract: A mechanism is provided for high-throughput compression of data. Responsive to receiving an indication of a match of a current 4-byte sequence from an incoming data stream to stored hash values in a set of hash tables, numerous variables are set to initial values. Responsive to receiving a subsequent 4-byte sequence from the incoming data stream and determining that an active match variable is set to one, the subsequent 4-byte sequence is compared to data in a copy of the incoming data stream in memory at an active position with a predefined length offset. A constraint variable is set to a number of bytes for which the match is to be extended. Responsive to the constraint variable being below a predetermined number, a length, distance pair is output indicating a match to a previous pattern in the incoming data stream.

Abstract: A computer-implemented method, according to one embodiment, includes: repeating the following sequence at least until a page stripe of a memory cache has at least a predetermined amount of data stored therein: finding an open codeword having an amount of available space which is greater than or equal to a size of a compressed logical page, and storing the compressed logical page in the open codeword having the amount of available space which is greater than or equal to a size of the compressed logical page. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: A technique for adapting over-provisioning space in a storage system includes determining one or more workload characteristics in the storage system. Over-provisioning space in the storage system is then adjusted to achieve a target write amplification for the storage system, based on the workload characteristics.

Abstract: Methods and apparatus 3 are provided for encoding data for storage in multilevel memory cells 2 having q cell-levels. Input data words are encoded into respective codewords, each having N symbols with one of q symbol-values, via an encoding scheme adapted such that the q symbol-values have unequal multiplicities within at least some codewords, and the multiplicity of each of the q symbol-values in every codeword is no less than ?, where ??2 and more preferably ?3. A first type of encoding scheme uses recursive symbol-flipping to enforce the ?-constraint, adding indicator symbols to indicate the flipped symbols. A second type of encoding scheme maps data words to codewords of a union of permutation codes, the initial vectors for these permutation codes being selected to enforce the ?-constraint. The N qary symbols of each codeword are supplied for storage in respective cells of the multilevel memory 2.

Abstract: A mechanism is provided in a non-volatile memory controller for reducing read access latency by straddling pages across non-volatile memory channels. Responsive to a request to write a logical page to a non-volatile memory array, the non-volatile memory controller determines whether the logical page fits into a current physical page. Responsive to determining the logical page does not fit into the current physical page, the non-volatile memory controller writes a first portion of the logical page to a first physical page in a first block and writes a second portion of the logical page to a second physical page in a second block. The first physical page and the second physical page are on different non-volatile memory channels.

Abstract: A multidimensional storage array (SA) system includes storage elements (SEs) arranged in storage array partitions, a plurality of input shifters, and a plurality of output shifters. One respective input shifter and output shifter is associated with one partition. The SEs are arranged into rows and columns and each store particular bit(s) of a data word. Each of the input shifters implements a positional shift to a data word that is then loaded to the associated partition. Each of the output shifters unloads a loaded data word, reverses the positional shift of the unloaded data word, and provides the data word to a requesting device, such as a decoder. The loaded data words are exposed so that multiple row or column addressed data words may be unloaded from the SA simultaneously in a single clock cycle. Multiple column or row address data word segments may be physically diagonally arranged within each storage array partition.

Abstract: In one embodiment, an apparatus includes one or more memory devices, each memory device having non-volatile memory configured to store data, and a memory controller connected to the one or more memory devices, the memory controller being configured to receive data to be stored to the one or more memory devices, store read-hot data within one error correction code (ECC) codeword as aligned data, and store read-cold data to straddle two or more ECC codewords as non-aligned data and/or dispersed data. According to another embodiment, a method for storing data to non-volatile memory includes receiving data to store to one or more memory devices, each memory device including non-volatile memory configured to store data, storing read-hot data within one ECC codeword as aligned data, and storing read-cold data to straddle two or more ECC codewords as non-aligned data and/or dispersed data.

Abstract: A method, according to one embodiment, includes repeating the following sequence at least until a page stripe of a memory cache has at least a predetermined amount of data stored therein: receiving a compressed logical page of data, finding an open codeword having an amount of available space which is greater than or equal to a size of the compressed logical page, and storing the compressed logical page in the open codeword having the amount of available space which is greater than or equal to a size of the compressed logical page. The compressed logical page does not straddle out of the open codeword. Other systems, methods, and computer program products are described in additional embodiments.