Seagate Technology Incorporated

David W Claude

Daniel John Benjamin

Ryan James Goss

Steven Scott Williams

Stacey Secatch

Ryan Charles Weidemann

Graham David Ferris

Kyumsung Lee

Thomas V Spencer

Matthew B Lovell

Benjamin J Scott

Stephen H Perlmutter

Jeff Rogers

A data storage system may have a plurality of memory cells located in different data storage devices that are arranged into a plurality of logical namespaces with each logical namespace configured to be sequentially written and entirely erased as a single unit. An asymmetry strategy may be proactively created with the asymmetry module in response to data access activity to the logical namespaces by the asymmetry module. A new mode, as prescribed by the asymmetry strategy, is entered for at least one logical namespace in response to an operational trigger being met. The new mode changes a timing of at least one queued data access request to at least one logical namespace.

Data storage system with workload-based asymmetry compensation

A data storage system may have a data storage device with a memory arranged into a plurality of logical namespaces. A power module can be connected to the plurality of logical namespaces and configured to transition at least one memory cell in response to a workload computed for a namespace of the plurality of the logical namespaces to maintain a power consumption of 8 watts or less for the data storage device.

Data storage system with workload-based dynamic power consumption

A system can log data access activity to a memory array with a metadata module while the memory array is logically divided into multiple namespaces. A workload can be determined for each namespace by the metadata module and a metadata strategy can be created with the metadata module in view of the respective namespace workloads. A first metadata and second metadata may be generated for respective first and second user-generated data for storage into a first namespace of the multiple namespaces. The first metadata can be compressed with a compression level prescribed by the metadata strategy in response to a detected or predicted workload to the first namespace before the first metadata, second metadata, first user-generated data, and second user-generated data are each stored in the first namespace.

Lossless namespace metadata management system

Method and apparatus for enhancing performance of a storage device, such as a solid-state drive (SSD). In some embodiments, the storage device monitors a rate at which client I/O access commands are received from a client to transfer data with a non-volatile memory (NVM) of the storage device. A ratio of background access commands to the client I/O access commands is adjusted to maintain completion rates of the client I/O access commands at a predetermined level. The background access commands transfer data internally with the NVM to prepare the storage device to service the client I/O access commands, and can include internal reads and writes to carry out garbage collection and metadata map updates. The ratio may be adjusted by identifying a workload type subjected to the storage device by the client.

Client input/output (I/O) access rate variation compensation

Apparatus and method for managing metadata in a data storage device such as a solid-state drive (SSD). The metadata are stored in combined (combo) pages in a non-volatile memory (NVM) each having first and second level map entries. The second level map entries provide a logical-to-physical address translation layer for user data blocks stored to the NVM, and the first level map entries describe the second level map entries in the combo page. A global map structure is accessed to identify a selected combo page in the NVM associated with a pending access command. The first and second level map entries are retrieved from the combo page, and the second level map entries are used to identify a target location for the transfer of user data blocks to or from the NVM.

Combined page footer for parallel metadata storage

Apparatus and method for managing metadata in a data storage device, such as a solid-state drive (SSD). In some embodiments, a non-volatile memory (NVM) includes a population of semiconductor memory dies. The dies are connected a number of parallel channels such that less than all of the semiconductor dies are connected to each channel. A controller circuit apportions the semiconductor memory dies into a plurality of die sets, with each die set configured to store user data blocks associated with a different user. A separate set of map data is generated to describe user data blocks stored to each die set. The controller circuit stores the respective sets of map data in the associated die sets so that no die set stores map data associated with a different die set. The die sets may be arranged in accordance with the NVMe (Non-Volatile Memory Express) specification.

Segregating map data among different die sets in a non-volatile memory

Apparatus and method for object storage, such as a solid-state drive (SSD) or array thereof. In some embodiments, data arranged as an object are presented for storage to a non-volatile memory (NVM) of a data storage device. Prior to storage, a configuration of the NVM is adaptively adjusted, such as by adjusting a garbage collection unit (GCU) layout, an error correction code (ECC) scheme, and/or a map metadata format used by the NVM. The object is thereafter stored to the NVM using the adaptively adjusted configuration. A controller of the data storage device generates a predicted remaining storage capacity of the NVM in terms of additional objects that can be stored by the NVM responsive to the adaptively adjusted configuration of the NVM. A non-linear sliding scale may be used such that a greater number of smaller objects or a smaller number of larger objects may be accommodated.

Data storage device with adaptive object storage capabilities

A semiconductor data storage memory can receive data access commands into a queue in a first time sequence that correspond with the transfer of data between a host and portions of the memory. The memory may be divided into separate portions that each have a different owner and the access commands may be issued to each of the respective separate portions. The access commands can subsequently be executed in a different, second time sequence responsive to estimated completion times for each of the access commands based on measured completion times for previously serviced, similar commands to maintain a nominally consistent quality of service level for each of the respective owners.

Deterministic optimization via performance tracking in a data storage system

Method and apparatus for managing data in a storage device, such as a solid-state drive (SSD). In some embodiments, a first read command from a command queue is forwarded to a non-volatile memory (NVM) to request retrieval of a first set of readback data. While the NVM initiates in-process execution of the first read command, an expanded read command is issued to the NVM. The expanded read command supercedes the first read command and requests an expanded set of readback data that includes the first set of readback data as well as a second set of readback data. The second set of readback data may be associated with a second read command in the command queue. The NVM transfers the expanded set of readback data to a read buffer responsive to the expanded read command. The first and second read commands may be client reads, background reads or both.

Combining in-process reads to reduce die collisions

A data storage system can arrange semiconductor memory into a plurality of die sets where performance metrics of execution of a first data access command to a first die set and of a second data access command to a second die set are measured. A proactive strategy is generated to maintain consistent data access command execution performance with a quality of service module based on the measured performance metrics and a third data access command is altered, as directed by the proactive strategy, to prevent a predicted non-uniformity of data access command performance between the first die set and the second die set.

Balanced die set execution in a data storage system

Apparatus and method for managing entropy in a cryptographic processing system, such as but not limited to a solid-state drive (SSD). In some embodiments, a processing device is operated to transfer data between a host device and a non-volatile memory (NVM). In response to the detection of a power down event associated with the processing device, entropy associated with the power down event is collected and stored in a memory. Upon a subsequent reinitialization of the processing device, the entropy is conditioned and used as an input to a cryptographic function to subsequently transfer data between the host device and the NVM. In some embodiments, the entropy is obtained from the state of a hardware timer that provides a monotonically increasing count for timing control. In other embodiments, the entropy is obtained from a RAID buffer used to store data to a die set of the NVM.

Collection of uncorrelated entropy during a power down sequence

A system may consist of a network controller connected between a non-volatile memory and a host with a disturb module connected to the non-volatile memory. A received data write request from a host may prompt the assignment of a first physical block address in the non-volatile memory to a data block of the data write request with the network controller. The data block and first physical block address can each be characterized with the disturb module before the first physical block address is altered to a second block address in the non-volatile memory in response to a disturb strategy generated by the disturb module. The second block address can be selected based on the characterization of the data block and first physical block address with respect to a risk of a disturb condition occurring in the non-volatile memory.

Data storage system with read disturb control strategy whereby disturb condition can be predicted

Method and apparatus for enhancing power cycle performance of a storage device, such as a solid-state drive (SSD). In some embodiments, map data that describe the contents of a non-volatile memory (NVM) are arranged as snapshots and intervening journal updates. During a scram interval in which the storage device transitions to a powered down condition, the snapshots and journal updates for primary segments with high client interest are updated prior to storage to the NVM. During a reinitialization interval in which the storage device transitions to a powered up condition, the updated primary segments are loaded, after which the storage device provides the client device with an operationally ready notification. Remaining secondary segments are updated and loaded after the notification. The primary segments are identified based on a detected workload from the client device. Configuration changes can further be made based on the detected workload.

Storage device with enhanced time to ready performance

Method and apparatus for managing data in a storage device, such as a solid-state drive (SSD). In some embodiments, write and read commands from a client device are placed into a command queue pending servicing to transfer data between the client device and a non-volatile memory (NVM). A write cache temporarily stores sets of writeback data pending transfer. A cache manager detects an overlap condition in which a subsequently received command at least partially overlaps a pending write command. In response, the cache manager enacts a change in caching policy that includes retention of the cached writeback data to aid in the servicing of the subsequently received command. The changes in caching policy can include an increase in the size of the write cache, delays in the writing of hot writeback data sets, the coalescing of different writeback data sets, cache hits using the cached writeback data, etc.

Managing overlapping reads and writes in a data cache

Apparatus and method for managing metadata in a data storage device, such as a solid-state drive (SSD). In some embodiments, a non-volatile memory (NVM) includes a population of semiconductor memory dies. The dies are connected a number of parallel channels such that less than all of the semiconductor dies are connected to each channel. A controller circuit apportions the semiconductor memory dies into a plurality of die sets, with each die set configured to store user data blocks associated with a different user. The controller circuit subsequently rearranges the dies into a different arrangement of die sets so that at least one die is migrated from a first dies set to a second die set. A map manager circuit is configured to establish an array of pointers in a memory to identify contiguous portions of map metadtata that describe user data stored in the at least one migrated die.

Growing community of inventors

Loveland, CO, United States of America

David W Claude