Apple Inc.

Sandisk Technologies Inc.

Alexander Paley

Andrew W Vogan

Sergey Anatolievich Gorobets

Alan David Bennett

Matthew John Byom

Shai Traister

Eugene Zilberman

Andrew John Tomlin

William S Wu

Bum Suck So

Muhammad N Ashraf

Yuhua Liu

Tudor Antoniu

Evgeny Televitckiy

Avraham Poza Meir

Micha Anholt

Vadim Khmelnitsky

Barak Baum

Roman Guy

Eran Sandel

Liran Erez

Lior Mouler

Asif Sade

Avraham Meir

Systems and methods for balancing multiple partitions of non-volatile memory devices are provided. Embodiments discussed herein execute a balance proportion scheme in connection with a NVM that is partitioned to have multiple partition types. Each partition type has an associated endurance that defines an average number of program/erase (P/E) cycles it can endure before it reaches failure. For example, a first partition type may have a substantially greater endurance than a second partition type. The balance proportion scheme ensures that, even though each partition type has a different associated endurance, all partition types are used proportionally with respect to each other to balance their respective P/E cycles. This way, both partition types will reach the upper limits of their respective endurance levels out at approximately the same time.

Systems and methods for balancing multiple partitions of non-volatile memory

Disclosed herein are techniques for balancing write commands directed to a non-volatile memory. According to some embodiments, a method may include caching a plurality of write commands into a write cache, and, in response to determining that an available capacity of the write cache satisfies a first threshold value: performing at least one write operation by directing data associated with the write commands in the write cache to the first partition of the non-volatile memory in response to determining that an available capacity of a first partition of the non-volatile memory satisfies a second threshold value; and performing at least one write operation by directing data associated with the write commands in the write cache to a second partition of the non-volatile memory in response to determining that the available capacity of the first partition of the non-volatile memory does not satisfy the second threshold value.

Techniques for balancing write commands on solid state storage devices (SSDs)

Disclosed herein are techniques for managing context information for data stored within a non-volatile memory of a computing device. According to some embodiments, the method can include (1) loading, into a volatile memory of the computing device, the context information from the non-volatile memory, where the context information is separated into a plurality of silos, (2) writing transactions into a log stored within the non-volatile memory, and (3) each time a condition is satisfied: (i) identifying a next silo of the plurality of silos to be written into the non-volatile memory, (ii) updating the next silo to reflect the transactions that apply to the next silo, and (iii) writing the next silo into the non-volatile memory. In turn, when an inadvertent shutdown of the computing device occurs, the silos of which the context information is comprised can be sequentially accessed and restored in an efficient manner.

Techniques for managing context information for a storage device

Disclosed are techniques for managing context information for data stored within a computing device. According to some embodiments, the method can include the steps of (1) loading, into a volatile memory of the computing device, the context information from a non-volatile memory of the computing device, where the context information is separated into a plurality of portions, and each portion of the plurality of portions is separated into a plurality of sub-portions, (2) writing transactions into a log stored within the non-volatile memory, and (3) each time a condition is satisfied: identifying a next sub-portion to be processed, where the next sub-portion is included in the plurality of sub-portions of a current portion being processed, identifying a portion of the context information that corresponds to the next sub-portion, converting the portion from a first format to a second format, and writing the portion into the non-volatile memory.

Techniques for managing context information for a storage device while maintaining responsiveness

Disclosed herein are techniques for managing parity information for data stored on a storage device. A method includes (1) receiving a request to store data into the storage device, (2) storing portions of the data in data pages included in stripes in a band of the storage device, where a respective data page is stored on a respective different die of a respective stripe, (3) determining primary parity information for a first stripe including a subset of the data pages, (4) storing the primary parity information in a primary parity page included in a second stripe in the stripes in the band, where the primary parity page is disposed on a next available die relative to dies storing the data pages, (5) determining secondary parity information for the second stripe, and (6) storing the secondary parity information in a secondary parity page included in the stripes in the band.

Managing parity information for data stored on a storage device

Disclosed herein are techniques for reducing write amplification when processing write commands directed to a non-volatile memory. According to some embodiments, the method can include the steps of (1) receiving a first plurality of write commands and a second plurality of write commands, where the first plurality of write commands and the second plurality of write commands are separated by a fence command (2) caching the first plurality of write commands, the second plurality of write commands, and the fence command, and (3) in accordance with the fence command, and in response to identifying that at least one condition is satisfied: (i) issuing the first plurality of write commands to the non-volatile memory, (ii) issuing the second plurality of write commands to the non-volatile memory, and (iii) updating log information to reflect that the first plurality of write commands precede the second plurality of write commands.

Techniques for reducing write amplification on solid state storage devices (SSDs)

Systems and methods for managing non-volatile memory devices are provided. Embodiments discussed herein provide rapid restart protection for journaling system. The rapid restart protection prevents the NVM from experiencing memory saturation when the NVM system is being forced to handle multiple successive restarts.

Rapid restart protection for a non-volatile memory system

Disclosed herein are techniques for managing parity information for data stored on a storage device. According to some embodiments, the method includes the steps of (1) receiving a request to store data into the storage device, (2) writing respective portions of the data into a plurality of data pages included in a first stripe of the storage device, where each data page is stored on a respective different die of the storage device, (3) calculating primary parity information for the first stripe, (4) writing the primary parity information into a primary parity page included in a second stripe of the storage device, (5) calculating secondary parity information for the second stripe, and (6) writing the secondary parity information into a secondary parity page included in a third stripe of the storage device. Additionally, a copy of the secondary parity information can be established to further-enhance redundancy.

Techniques for managing parity information for data stored on a storage device

An apparatus includes an interface and a processor. The interface is configured to communicate with a non-volatile memory. The processor is configured to hold a translation table that maps between logical addresses and respective physical addresses in the non-volatile memory, to back-up to the non-volatile memory a baseline version of the translation table in one or more bulks, to additionally back-up to the non-volatile memory one or more incremental updates, which specify changes relative to the baseline version of the translation table caused by subsequent storage operations, to determine a maximal number of the incremental updates that, when recovered together with the baseline version from the non-volatile memory and replayed in the processor, meets a target recovery time of the translation table, and to set a number of the backed-up incremental updates to not exceed the maximal number.

Managing backup of logical-to-physical translation information to control boot-time and write amplification

Systems and methods for handling sudden power failures in non-volatile memory devices such as solid state drives are provided by having the non-volatile memory device boot up in a low power write mode, which limits substantially all programming operations to a single level cell (SLC) mode, as opposed to a normal mode in which the programming operations can be performed in a multi-level cell (MLC) mode. Thus, if the system experiences a sudden power failure when it is being powered solely by AC derived power and the battery is below a level sufficient for powering the device while it is programming in the SLC mode, data integrity will be preserved because the programming operation was being performed in SLC mode. The non-volatile memory device may be permitted to exit out the low power write mode into the normal mode when the charge level of the battery is sufficient for powering the system.

Systems and methods for handling sudden power failures in solid state drives

A method includes calculating redundancy information over a set of data items, and sending the data items for storage in a memory. The redundancy information is retained only until the data items are written successfully in the memory, and then discarded. The data items are recovered using the redundancy information upon a failure in writing the data items to the memory.

Data protection from write failures in nonvolatile memory

A method for data storage includes storing data in a memory including multiple analog memory cells arranged in blocks. A first subset of the blocks is defined for storing first data with a first storage density, and a second subset of the blocks is defined for storing second data with a second storage density, larger than the first storage density. In each of the first and second subsets, one or more blocks are allocated to serve as spare blocks and blocks that become faulty are replaced with the spare blocks. Upon detecting that a number of the spare blocks in the second subset has decreased below a predefined threshold, the data is copied from at least one block in the second subset to the first subset, and the at least one block is added to the spare blocks of the second subset.

Block management schemes in hybrid SLC/MLC memory

A portion of a nonvolatile memory is partitioned from a main multi-level memory array to operate as a cache. The cache memory is configured to store at less capacity per memory cell and finer granularity of write units compared to the main memory. In a block-oriented memory architecture, the cache has multiple functions, not merely to improve access speed, but is an integral part of a sequential update block system. Decisions to archive data from the cache memory to the main memory depend on the attributes of the data to be archived, the state of the blocks in the main memory portion and the state of the blocks in the cache portion.

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Cupertino, CA, United States of America

Alexander Paley