Abstract: A storage system with garbage collection prioritizes data segments for garbage collection in the storage memory. Priority of each data segment relates to amount of processing device work for garbage collection of the data segment versus benefit relating to amount of dead data to be reclaimed by garbage collection of the data segment. Garbage collection is performed according to the priority of each data segment.

Abstract: A storage system determines a present amount of reclaimable space in storage memory. The storage system determines a garbage collection directive based on the present amount of reclaimable space in comparison to a target amount of reclaimable space. The storage system selects blocks of storage memory for a group of blocks for garbage collection. Each block selected has greater than or equal to a threshold amount of reclaimable space in accordance with the garbage collection directive. The storage system performs garbage collection, using blocks from the group.

Abstract: A storage system includes solid-state storage devices and a storage controller operatively coupled to the solid-state storage devices, the storage controller including a processing device, to store sets of data at one or more solid-state storage devices of the plurality of solid-state storage devices. The processing device may also generate tags for each of the sets of data based on one or more metadata items associated with each set of data. The processing device may also determine an expected lifespan for each set of data based on the one or more tags generated for the respective set of data. The processing device may also group each of the one or more sets of data into respective ones of a plurality of memory blocks based on the expected lifespan for each set of data, wherein each memory block corresponds to sets of data of a particular expected lifespan.

Abstract: A storage system performs garbage collection with data compression. A storage controller in the storage system determines a garbage collection directive by evaluating the amount of reclaimable space relative to a target amount of reclaimable space. Garbage collection is performed using data compression tunable to compression aggressiveness according to the garbage collection directive.

Abstract: A system and method of uniform sampling in an append-only database to determine temporal distribution of data.

Abstract: A storage controller coupled to a storage array comprising one or more storage devices performs a uniform sampling of data storage items in an append-only file system to identify a sample set and identifies at least two data storage item groups based on an age of the data storage items. The storage controller performs a garbage collection process on the append-only file system to identify stale data storage items in a first logical storage segment and active data storage items in the first logical storage segment and writes a first active data storage item associated with a first group of the two data storage item groups from the first logical storage segment to a second logical storage segment, the second logic storage segment comprising other active data storage items associated with the first group.

Abstract: The present invention provides a high-power adjustable high-frequency fractional order capacitor with an order greater than 1, and a control method thereof. The fractional-order capacitor comprises an alternating current input module, a coupling impedance, a high-frequency alternating current controlled voltage source, a controller and an alternating current input sampling module. The controller generates a corresponding control signal according to an input voltage signal and an input current signal which are acquired by the alternating current input sampling module, and controls an output voltage of the controlled power source, such that an input current and an input voltage satisfy a current-voltage relationship of the fractional-order capacitor. The obtained relationship between the input current and the input voltage is consistent with the definition of the fractional-order capacitor with the order greater than 1.

Abstract: The present invention provides a high-power adjustable high-frequency fractional order capacitor with an order greater than 1, and a control method thereof. The fractional-order capacitor comprises an alternating current input module, a coupling impedance, a high-frequency alternating current controlled voltage source, a controller and an alternating current input sampling module. The controller generates a corresponding control signal according to an input voltage signal and an input current signal which are acquired by the alternating current input sampling module, and controls an output voltage of the controlled power source, such that an input current and an input voltage satisfy a current-voltage relationship of the fractional-order capacitor. The obtained relationship between the input current and the input voltage is consistent with the definition of the fractional-order capacitor with the order greater than 1.