760 results about "Solid-state storage" patented technology

An apparatus, system, and method are disclosed for storage space recovery after reaching a read count limit. A read module reads data in a storage division of solid-state storage. A read counter module then increments a read counter corresponding to the storage division. A read counter limit module determines if the read count exceeds a maximum read threshold, and if so, a storage division selection module selects the corresponding storage division for recovery. A data recovery module reads valid data packets from the selected storage division, stores the valid data packets in another storage division of the solid-state storage, and updates a logical index with a new physical address of the valid data.

A non-volatile solid-state storage subsystem, such as a non-volatile memory device, maintains usage statistics reflective of the wear state, and thus the remaining useful life, of the subsystem's memory array. A host system reads the usage statistics information, or data derived therefrom, from the subsystem to evaluate the subsystem's remaining life expectancy. The host system may use this information for various purposes, such as to (a) display or report information regarding the remaining life of the subsystem; (b) adjust the frequency with which data is written to the subsystem; and / or (c) select the type(s) of data written to the subsystem.

An apparatus, system, and method are disclosed for caching data on a solid-state storage device. The solid-state storage device maintains metadata pertaining to cache operations performed on the solid-state storage device, as well as storage operations of the solid-state storage device. The metadata indicates what data in the cache is valid, as well as information about what data in the nonvolatile cache has been stored in a backing store. A backup engine works through units in the nonvolatile cache device and backs up the valid data to the backing store. During grooming operations, the groomer determines whether the data is valid and whether the data is discardable. Data that is both valid and discardable may be removed during the grooming operation. The groomer may also determine whether the data is cold in determining whether to remove the data from the cache device. The cache device may present to clients a logical space that is the same size as the backing store. The cache device may be transparent to the clients.

Embodiments of the solid-state storage system provided herein are configured to perform improved mechanisms for testing of error recovery of solid state storage devices. In some embodiments, the system is configured to introduce or inject errors into data storage commands or operations performed in the non-volatile memory. Injected errors include corruption of data stored in the non-volatile memory, deliberate failure to execute storage operations, and errors injected into communication protocols used between various elements of the device. In some embodiments, injected errors can include direct errors that trigger an immediate execution of error recovery mechanisms and delayed errors that trigger execution of error recovery mechanisms at a later time. Error recovery mechanisms can be tested in an efficient, reliable, and deterministic manner to help ensure effective operation of storage devices. The integrity of non-volatile memory can also be tested.

A solid-state storage retention monitor determines whether user data in a solid-state device is in need of a scrubbing operation. One or more reference blocks may be programmed with a known data pattern, wherein the reference block(s) experiences substantially similar P / E cycling, storage temperature, storage time, and other conditions as the user blocks. The reference blocks may therefore effectively represent data retention properties of the user blocks and provide information regarding whether / when a data refreshing operation is needed.

A system and method for effectively scheduling read and write operations among a plurality of solid-state storage devices. 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 comprises an I / O scheduler. The storage controller is configured to receive a read request targeted to the data storage medium, and identify at least a first storage device of the plurality of storage devices which contains data targeted by the read request. In response to either detecting or predicting the first storage device will exhibit variable performance, the controller is configured to generate a reconstruct read request configured to obtain the data from one or more devices of the plurality of storage devices other than the first storage device.

An apparatus, system, and method are disclosed for destaging cached data. A controller detects one or more write requests to store data in a backing store. The cache controller sends the write requests to a storage controller for a nonvolatile solid-state storage device. The storage controller receives the write requests and caches the data associated with the write requests in the nonvolatile solid-state storage device by appending the data to a log of the nonvolatile solid-state storage device. The log includes a sequential, log-based structure preserved in the nonvolatile solid-state storage device. The cache controller receives at least a portion of the data from the storage controller in a cache log order and destages the data to the backing store in the cache log order. The cache log order comprises an order in which the data was appended to the log of the nonvolatile solid-state storage device.

An apparatus, system, and method are disclosed for managing a cache. A cache interface module provides access to a plurality of virtual storage units of a solid-state storage device over a cache interface. At least one of the virtual storage units comprises a cache unit. A cache command module exchanges cache management information for the at least one cache unit with one or more cache clients over the cache interface. A cache management module manages the at least one cache unit based on the cache management information exchanged with the one or more cache clients.

An apparatus, system, and method are disclosed for managing data in a solid-state storage device. A solid-state storage and solid-state controller are included. The solid-state storage controller includes a write data pipeline and a read data pipeline The write data pipeline includes a packetizer and an ECC generator. The packetizer receives a data segment and creates one or more data packets sized for the solid-state storage. The ECC generator generates one or more error-correcting codes (“ECC”) for the data packets received from the packetizer. The read data pipeline includes an ECC correction module, a depacketizer, and an alignment module. The ECC correction module reads a data packet from solid-state storage, determines if a data error exists using corresponding ECC and corrects errors. The depacketizer checks and removes one or more packet headers. The alignment module removes unwanted data, and re-formats the data as data segments of an object.

A solid-state storage system is described with a method for adjusting the frequency of data retention operations. The data retention operation frequency can be increased or decreased according to a variety of environmental factors such as error code frequency, system temperature, altitude, and other operating conditions. These factors can indicate an increased or decreased risk of failure and accordingly provide increased or decreased rates of data retention operations.

A latency reduction method for read operations of an array of N solid-state storage devices having n solid-state storage devices for data storage and p solid-state storage devices for storing parity data is provided. Utilizing the parity generation engine fault tolerance for a loss of valid data from at least two of the N solid-state storage devices, the integrity of the data is determined when N−1 of the solid-state storage devices have completed executing a read command. If the data is determined to be valid, the missing data of the Nth solid-state storage device is reconstructed and the data transmitted to the requesting processor. By that arrangement the time necessary for the Nth solid-state storage device to complete execution of the read command is saved, thereby improving the performance of the solid-state memory system.

A solid-state storage subsystem, such as a non-volatile memory card or drive, includes a main memory area that is accessible via standard memory access commands (such as ATA commands), and a restricted memory area that is accessible only via one or more non-standard commands. The restricted memory area stores information used to control access to, and / or use of, information stored in the main memory area. As one example, the restricted area may store one or more identifiers, such as a unique subsystem identifier, needed to decrypt an executable or data file stored in the main memory area. A host software component is configured to retrieve the information from the subsystem's restricted memory area, and to use the information to control access to and / or use of the information in the main memory area.

Embodiments of solid-state storage system are provided herein which reduce processing delays for performance-sensitive commands. These performance-sensitive commands are typically read-write commands which can be transferred to the storage media by a high performance path to optimize responsiveness to the host. This high performance path can be enabled and disabled to prevent conflicts with commands processed via a low performance path.

A non-volatile storage subsystem solution is provided for embedded applications. The storage subsystem is preferably designed to communicate with the host system using a signal interface, such as a USB or SATA interface, that uses substantially fewer signal lines than the IDE interface traditionally used for embedded applications. Thus, the amount of board real estate used to carry interface signals in the host system is reduced. To further reduce board real estate, the host system may include a processor that includes an integrated controller (e.g., a USB or SATA controller) corresponding to the host-subsystem signal interface. The storage subsystem may plug into, and lock to, an internal connector on a circuit board of the host system.

Embodiments of solid-state storage system are provided herein include data recovery mechanism to recover data upon detection of a read error (e.g., an uncorrectable ECC error) in a storage element such as a page. In various embodiments, the system is configured to determine optimal reference voltage value(s) by evaluating the reference voltage value(s) of page(s) that are related to the page where the failure occurred. The related page(a) may include a page that is paired with the initial page where the failure occurred (e.g., the paired pages reside in a common memory cell), or a neighboring page that is physically near the page where the initial page, and / or a paired page of the neighboring page. In another embodiment, the system is configured to perform a time-limited search function to attempt to determine optimal reference voltage values through an iterative process that adjusts voltage values in a progression to determine a set of values that can retrieve the data.

A data storage system is provided comprising several flash arrays in a board and stacking these boards to attain a high-capacity solid state hard drive. A remap table is used to map all logical addresses from a host system to the actual physical addresses where data are stored. The assignments of these physical locations are done in such a way that the load of the system is evenly distributed to its available resources. This would ensure that the storage system will run at its utmost efficiency utilizing its resources properly. To achieve this, the system would make sure that the physical location of data be evenly distributed according to the current load of the system.

An apparatus, system, and method are disclosed for bad block remapping. A bad block identifier module identifies one or more data blocks on a solid-state storage element as bad blocks. A log update module writes at least a location of each bad block identified by the bad block identifier module into each of two or more redundant bad block logs. A bad block mapping module accesses at least one bad block log during a start-up operation to create in memory a bad block map. The bad block map includes a mapping between the bad block locations in the bad block log and a corresponding location of a replacement block for each bad block location. Data is stored in each replacement block instead of the corresponding bad block. The bad block mapping module creates the bad block map using one of a replacement block location and a bad block mapping algorithm.

A solid-state storage subsystem, such as a non-volatile memory card or drive, includes multiple interfaces and a memory area storing information used by a data arbiter to prioritize data commands received through the interfaces. As one example, the information may store a priority ranking of multiple host systems that are connected to the solid-state storage subsystem, such that the data arbiter may process concurrently received data transfer commands serially according to their priority ranking. A host software component may be configured to store and modify the priority control information in solid-state storage subsystem's memory area.

A solid-state storage subsystem, such as a non-volatile memory card or drive, includes a main memory area that is accessible via standard memory access commands (such as ATA commands), and a restricted memory area that is accessible only via one or more non-standard commands. The restricted memory area stores information used to control access to, and / or use of, information stored in the main memory area. As one example, the restricted area may store one or more identifiers, such as a unique subsystem identifier, needed to decrypt an executable or data file stored in the main memory area. A host software component is configured to retrieve the information from the subsystem's restricted memory area, and to use the information to control access to and / or use of the information in the main memory area.

A system for configuring solid-state storage devices comprises a solid-state storage device and an error correction code (ECC) selection system. The ECC selection system is configured to automatically select a set of error correction code based on an error rate of the storage device. The ECC selection system is further configured to install the selected set of error correction code in the solid-state storage device.

Embodiments of the invention are directed to enabling concurrent commands from command requesters in a non-volatile solid-state storage subsystem in a manner that reduces contentions among the commands. Embodiments group blocks of memory into multiple sets of superblocks and associate a command requester to each superblock set. In one embodiment, the superblock sets are dynamically associated with a requester. In one embodiment, the superblock sets are dynamically associated with requesters based in part on at least one of internal memory management needs and host command throughput. In one embodiment, an erase command is executed on a superblock within a set and a simultaneous write command is executed on a superblock within another set.

An apparatus, system, and method are disclosed for determining a read voltage threshold for solid-state storage media. A data set read module reads a data set from storage cells of solid-state storage media. The data set is originally stored in the storage cells with a known bias. A deviation module determines that a read bias for the data set deviates from the known bias. A direction module determines a direction of deviation for the data set. The direction of deviation is based on a difference between the read bias of the data set and the known bias. An adjustment module adjusts a read voltage threshold for the storage cells of the solid-state storage media based on the direction of deviation.

An apparatus, system, and method are disclosed for caching data. A storage request module detects an input / output (“I / O”) request for a storage device cached by solid-state storage media of a cache. A direct mapping module references a single mapping structure to determine that the cache comprises data of the I / O request. The single mapping structure maps each logical block address of the storage device directly to a logical block address of the cache. The single mapping structure maintains a fully associative relationship between logical block addresses of the storage device and physical storage addresses on the solid-state storage media. A cache fulfillment module satisfies the I / O request using the cache in response to the direct mapping module determining that the cache comprises at least one data block of the I / O request.

A data storage subsystem is disclosed that implements a solid-state data buffering scheme. Prior to completion of programming in solid-state storage media, data that is formatted for storage in solid-state media is maintained in one or more buffers. The system is able to retry failed programming operations directly from the buffers, rather than reprocessing the data. The relevant programming pipeline may therefore be preserved by skipping over a failed write operation and reprocessing the data at the end of the current pipeline processing cycle.

An apparatus, system, and method are disclosed to improve the utility of solid-state storage media by determining one or more configuration parameters for the solid-state storage media. A media characteristic module references one or more storage media characteristics for a set of storage cells of solid-state storage media. A configuration parameter module determines a configuration parameter for the set of storage cells based on the one or more storage media characteristics. A storage cell configuration module configures the set of storage cells to use the determined configuration parameter.