Abstract: Method and apparatus for managing data in a non-volatile memory (NVM) of a storage device, such as a solid-state drive (SSD). Data are stored to and retrieved from a group of memory cells in the NVM using a controller circuit. The data are retrieved using a first set of read voltages which are applied to the respective memory cells. The first set of read voltages are accumulated into a history distribution, which is evaluated to arrive at a second set of read voltages based upon characteristics of the history distribution. A calibration operation is performed on the memory cells using the second set of read voltages as a starting point. A final, third set of read voltages is obtained during the calibration operation to provide error rate performance at an acceptable level. The third set of read voltages are thereafter used for subsequent read operations.

Abstract: Apparatus and method for a die kill and recovery sequence for a non-volatile memory (NVM). Data are stored in the NVM as data sets in garbage collection units (GCUs) that span multiple semiconductor dies. A die failure management circuit is configured to detect a die failure event associated with a selected die, and to generate a recovery strategy to accommodate the detected die failure event by selecting recovery actions to be taken in a selected sequence to maintain a current level of data transfer performance with a client device. The selected recovery actions are carried out in the selected sequence to transfer at least a portion of the user data stored in the selected die to a new replacement die, after which the selected die is decommissioned from further use. The NVM may be a flash memory of a solid-state drive (SSD).

Abstract: Failure-domain-specific cryptographic keys for use in control of access to data within failure domains of a storage drive. A unique failure domain-specific cryptographic key may be associated with each of a plurality of failure domains in a storage drive. The failure domains may correspond to any portion of the storage media of a drive that is susceptible to failure while leaving other portions of the storage drive functional. In turn, upon detection of a condition associated with a failure (e.g., an actual or predicted failure) of a failure domain, the associated failure domain-specific cryptographic key may be deleted to preclude further access to data in the failed failure domain. Deletion of the failure domain-specific cryptographic key may be before or after data in the failed failure domain is rebuilt in another portion of a storage drive that is functional.

Abstract: Method and apparatus for managing data in a non-volatile memory (NVM) of a storage device, such as a solid-state drive (SSD). Data are stored to and retrieved from a group of memory cells in the NVM using a controller circuit. The data are retrieved using a first set of read voltages which are applied to the respective memory cells. The first set of read voltages are accumulated into a history distribution, which is evaluated to arrive at a second set of read voltages based upon characteristics of the history distribution. A calibration operation is performed on the memory cells using the second set of read voltages as a starting point. A final, third set of read voltages is obtained during the calibration operation to provide error rate performance at an acceptable level. The third set of read voltages are thereafter used for subsequent read operations.

Abstract: Apparatus and method for managing a non-volatile memory (NVM) such as a flash memory in a solid-state drive (SSD). In some embodiments, the NVM is arranged as a plurality of semiconductor memory dies coupled to a controller circuit using a plurality of channels. The controller circuit divides the plurality of dies into a succession of garbage collection units (GCUs). Each GCU is independently erasable and allocatable for storage of user data. The GCUs are staggered so that each GCU is formed from a different subset of the dies in the NVM. In further embodiments, the dies are arranged into NVM sets in accordance with the NVMe (Non-Volatile Memory Express) specification with each NVM set addressable by a different user for storage of data in a separate set of staggered GCUs.

Abstract: Apparatus and method for a die kill and recovery sequence for a non-volatile memory (NVM). Data are stored in the NVM as data sets in garbage collection units (GCUs) that span multiple semiconductor dies. A die failure management circuit is configured to detect a die failure event associated with a selected die, and to generate a recovery strategy to accommodate the detected die failure event by selecting recovery actions to be taken in a selected sequence to maintain a current level of data transfer performance with a client device. The selected recovery actions are carried out in the selected sequence to transfer at least a portion of the user data stored in the selected die to a new replacement die, after which the selected die is decommissioned from further use. The NVM may be a flash memory of a solid-state drive (SSD).

Abstract: 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.

Abstract: 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.

Abstract: Systems and methods for encrypting system level data structures are described. A storage system may include a storage drive and at least one controller for the storage drive. In some embodiments, the at least one controller may be configured to identify user data assigned to be stored on the storage drive, encrypt the user data, identify a system data structure generated in relation to the user data, and encrypt the system data structure. In some cases, the data structure may include at least one of metadata, system data, and data encapsulation relative to the user data. In some embodiments, the user data and the data structure may be encrypted with one or more encryption keys programmed on the storage drive.

Abstract: 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.

Abstract: Method and apparatus for managing data in a data storage device configured as a storage compute appliance. In some embodiments, the data storage device has a non-volatile memory (NVM) and a controller circuit. The NVM stores a plurality of data sets encrypted by at least one encryption key. The controller circuit performs a storage compute appliance process by locally decrypting the plurality of data sets in a local memory of the data storage device, generating summary results data from the decrypted data sets, and transferring the summary results data across the host interface to an authorized user without a corresponding transfer of any portion of the decrypted data sets across the host interface.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Method and apparatus for managing data in a data storage device configured as a storage compute appliance. In some embodiments, the data storage device has a controller circuit and a non-volatile memory (NVM) with an overall data storage capacity. A processor authenticates each of a plurality of authorized users of the NVM via data exchanges between a host device and the processor without reference to an external authentication authority device. Upon authentication, each authorized user is allocated a separate portion of the overall data storage capacity of the NVM using an allocation model. The size of at least one of the separate portions is subsequently adjusted based on an access history of the NVM. The storage device may be a key-value storage device so that a separate set of key values is provided to each authorized user to identify data blocks stored to and retrieved from the NVM.

Abstract: A data storage system can connect a plurality of remote hosts to a plurality of die sets resident in a semiconductor memory. Execution of at least one data access command addressed by a remote host of the plurality of remote hosts can occur prior to a power interruption event being detected for at least one die set of the plurality of die sets. User-generated data associated with the at least one data access command may then be flushed to a predetermined location responsive to an available resource budget associated with the power interruption event.

Abstract: Apparatus and method for managing a non-volatile memory (NVM) such as a flash memory in a solid-state drive (SSD). In some embodiments, the NVM is arranged as a plurality of semiconductor memory dies coupled to a controller circuit using a plurality of channels. The controller circuit divides the plurality of dies into a succession of garbage collection units (GCUs). Each GCU is independently erasable and allocatable for storage of user data. The GCUs are staggered so that each GCU is formed from a different subset of the dies in the NVM. In further embodiments, the dies are arranged into NVM sets in accordance with the NVMe (Non-Volatile Memory Express) specification with each NVM set addressable by a different user for storage of data in a separate set of staggered GCUs.

Abstract: Apparatus and method for managing a non-volatile memory (NVM) such as a flash memory in a solid-state drive (SSD). In some embodiments, the NVM is arranged as a plurality of semiconductor memory dies coupled to a controller circuit using a plurality of channels. The controller circuit divides the plurality of dies into a succession of garbage collection units (GCUs). Each GCU is independently erasable and allocatable for storage of user data. The GCUs are staggered so that each GCU is formed from a different subset of the dies in the NVM. In further embodiments, the dies are arranged into NVM sets in accordance with the NVMe (Non-Volatile Memory Express) specification with each NVM set addressable by a different user for storage of data in a separate set of staggered GCUs.

Abstract: Systems and methods for encryption key shredding to protect non-persistent data are described. In one embodiment, the storage system device may include a storage drive and a controller. In some embodiments, the controller may be configured to power on the storage drive, identify an encryption key on the storage drive created upon powering on the storage drive, and encrypt data in a cache of the storage drive using the encryption key. In some embodiments, the controller may be configured to power off the storage drive and delete the encryption key upon powering off the storage drive. In some cases, the storage drive may include at least one of a solid state drive and a hard disk drive. In some embodiments, the storage drive may include a hybrid storage drive that includes both a solid state drive and a hard disk drive.

Abstract: Apparatus and method for managing shared resources in a data storage device such as a solid-state drive (SSD). In some embodiments, a non-volatile memory (NVM) has a population of semiconductor memory dies which are divided into die sets for different users. Each die set includes user garbage collection units (GCUs) for storage of user data blocks by the associated user and overprovisioned global GCUs to store user data blocks from the users of the other die sets. When an imbalance condition exists such that the workload traffic level of a first die set exceeds a workload traffic level of a second die set, at least one host I/O command for the first die set is offloaded for servicing using a selected global GCU of the second die set. The offloaded data may be subsequently transferred to the first die set after the imbalance condition is resolved.