Example object storage systems, bookkeeping engines, and methods provide quota usage monitoring for control entities, such as accounts, users, and buckets. An object data store is configured to enable control entities to access data objects associated with each control entity. Data objects are mapped to the control entities and the data objects are processed to identify object usage values corresponding to each combination of data object and control entity. Total usage values are calculated for each control entity and used to determine a data object access response for a target data object and associated control entities.

According to some examples, systems and methods are provided for determining a set of power states supported by a data storage device and applying an operation to the data storage device based on whether the set of power states includes a low power state.

Methods, systems, and devices for storing and reading data at a memory device are described. A memory device may utilize one or more storage states to store data within a data word. The memory device may exhibit higher data leakage or more power consumption when storing or reading a first storage state compared to storing or reading one or more other storage states. In some cases, the memory device may generate a second data word corresponding to a first data word by modifying each symbol type of the first data word to generate a different symbol type for the second data word. A memory device may reduce the occurrence of a storage state associated with large data leakage, or high-power consumption, or both. Further, the memory device may generate and store an indicator indicating the transformation of a corresponding data word.

A method, system, and device for writing compressed data to a disk, and a readable storage medium. The method includes: acquiring compressed data, and determining a length of the compressed data; storing the compressed data in a linked list, and adding the length of the compressed data to a linked list length, wherein the linked list length is a total length of all compressed data in the linked list; determining whether the linked list length exceeds a threshold value; and if YES, allocating an idle thread to merge all the compressed data in the linked list, and carrying out a write-to-disk operation on the merged compressed data.

Determining which data should be located in each partition of a hard disk drive storage device based on growth values and/or data access frequency values.

Innovations in the area of server-side processing when committing transactions to disk in a distributed database system can improve computational efficiency at database nodes and/or reduce network bandwidth utilization. For example, when transactions are committed in a database system, at a master node of the database system, a server uses different threads for certain processor-intensive operations and certain I/O-intensive operations.

A memory controller managing a memory device receives a memory read command from a host device that is communicably coupled to the memory device. The memory device includes a storage memory comprising a first type of memory cells and a cache memory comprising a second type of memory cells. The memory controller determines, from the memory read command, a physical address of a target memory location in the storage memory indicated by the memory read command. The memory controller executes a read operation on the target memory location corresponding to the physical address. The memory controller determines a read attribute of the target memory location. Conditioned on determining that the read attribute satisfies one or more threshold conditions, the memory controller programs an entry in the cache memory with information corresponding to the target memory location.

A data storage device 100 comprising: a non-volatile storage medium 108 configured to store user data 109; a data port 106 configured to transmit data and power between a host computer system 130 and the data storage device 100; a data access state indicator 140; and a controller 110 configured to: selectively set a data access state of the data storage device 100 to either: an unlocked state to enable access to the user data 109; or a locked state to disable access to the user data 109; and generate an indicator control signal to cause the data access state indicator 140 to indicate the data access state, wherein the data access state indicator 140 is configured to indicate the data access state irrespective of whether the data storage device 100 is powered through the data port 106.

Techniques are provided for adaptive look-ahead configuration for data prefetching. One method comprises, in response to a request for a data item in a storage system: obtaining a size of a look-ahead window for the request based on one of multiple available caching policies; and moving the requested data item and additional data items within the look-ahead window to the cache memory when the requested data item and/or the additional data items within the look-ahead window are not in the cache memory. The multiple available caching policies comprise a caching policy based on characteristics of an input/output workload of the storage system, or a portion thereof; and/or a caching policy based on an input/output workload of at least a portion of the storage system within a prior predefined time window. The look-ahead window size may be varied over time.

Techniques provide for managing data storage. The techniques involve in response to receiving a request for unmapping a logical storage unit associated with a first disk slice on a first physical disk and the first disk slice, determining information associated with the first disk slice; generating, based on the information, a first entry and a second entry corresponding to the first disk slice; adding the first entry into a queue of failed disk slices to enable data stored on the first disk slice to be cleared; and adding the second entry into a queue of free disk slices to enable the first disk slice to be mapped to a further logical storage unit. Accordingly, such techniques can remarkably improve the write I/O performance of the system and prolong the lifetime of the SSD.