Abstract: Example implementations relate to storing data in a storage system. An example includes receiving, by a storage controller of a storage system, a data unit to be stored in persistent storage of the storage system. The storage controller calculates multiple entropy values for the data unit. The storage controller selects, based on the multiple entropy values, at least one reduction operation from multiple different reduction operations. The storage controller performs the selected at least one reduction operation on the received data unit.

Abstract: Example implementations relate to storing data in a storage system. An example includes receiving, by a storage controller of a storage system, a data unit to be stored in persistent storage of the storage system. The storage controller determines maximum and minimum entropy values for the received data unit. The storage controller determines, based on at least the minimum entropy value and the maximum entropy value, whether the received data unit is viable for data reduction. In response to a determination that the received data unit is viable for data reduction, The storage controller performs at least one reduction operation on the received data unit.

Abstract: Example implementations relate to storing data in a storage system. An example includes receiving, by a storage controller of a storage system, a data unit to be stored in persistent storage of the storage system. The storage controller determines maximum and minimum entropy values for the received data unit. The storage controller determines, based on at least the minimum entropy value and the maximum entropy value, whether the received data unit is viable for data reduction. In response to a determination that the received data unit is viable for data reduction, The storage controller performs at least one reduction operation on the received data unit.

Abstract: To provide enhanced operation of data storage devices and systems, various systems, apparatuses, methods, and software are provided herein. In a first example, a data storage system is presented. The data storage system includes data storage devices configured for storage and retrieval of data, power supply modules configured to provide power to at least the plurality of data storage devices, and a management controller configured to monitor power properties associated with the power supply modules to detect a degraded power condition. Responsive to the degraded power condition, the management controller is configured to establish adjustments to performance of the data storage devices to mitigate the degraded power condition.

Abstract: A data storage system and associated method are provided wherein a policy engine continuously collects qualitative information about a network load to the data storage system in order to dynamically characterize the load and continuously correlates the load characterization to the content of a command queue of transfer requests for writeback commands and host read commands, selectively limiting the content with respect to writeback commands to only those transfer requests for writeback data that are selected on a physical zone basis of a plurality of predefined physical zones of a storage media.

Abstract: To provide enhanced operation of data storage devices and systems, various systems, apparatuses, methods, and software are provided herein. In a first example, a data storage system is presented. The data storage system includes data storage devices configured for storage and retrieval of data, power supply modules configured to provide power to at least the plurality of data storage devices, and a management controller configured to monitor power properties associated with the power supply modules to detect a degraded power condition. Responsive to the degraded power condition, the management controller is configured to establish adjustments to performance of the data storage devices to mitigate the degraded power condition.

Abstract: A data storage system and associated method are provided wherein a policy engine continuously collects qualitative information about a network load to the data storage system in order to dynamically characterize the load and continuously correlates the load characterization to the content of a command queue of transfer requests for writeback commands and host read commands, selectively limiting the content with respect to writeback commands to only those transfer requests for writeback data that are selected on a physical zone basis of a plurality of predefined physical zones of a storage media.

Abstract: A data storage system and associated method are provided wherein a policy engine continuously collects qualitative information about a network load to the data storage system in order to dynamically characterize the load and continuously correlates the load characterization to the content of a command queue of transfer requests for writeback commands and host read commands, selectively limiting the content with respect to writeback commands to only those transfer requests for writeback data that are selected on a physical zone basis of a plurality of predefined physical zones of a storage media.

Abstract: As apparatus and associated method for a dual active-active array storage system with a first controller with top level control of a first memory space and a second controller with top level control of a second memory space different than the first memory space. A seek manager residing in only one of the controllers defines individual command profiles derived from a combined list of data transfer requests from both controllers. A policy engine continuously collects qualitative information about a network load to both controllers to dynamically characterize the load, and governs the seek manager to continuously correlate each command profile in relation to the load characterization.

Abstract: A data storage system and associated method implement a HASTE with a policy engine that continuously collects qualitative information about a network load to the data storage system in order to dynamically characterize the load, and continuously correlates a command profile to a data storage device of the data storage system in relation to the characterization.

Abstract: Apparatus and method for command queue management of back watered requests. A selected request is released from a command queue, and further release of requests from the queue is interrupted when a total number of subsequently completed requests reaches a predetermined threshold.

Abstract: Apparatus and method for efficiently arranging and searching data in a memory space, such as a cache memory of a data storage array controller. A data structure comprises a skip list of nodes having an array of forward pointers. Each node has a node level derived from an index at which the node is stored in a table in the memory space. The total available number of nodes is preferably selected to be less than half of the largest power of 2 that can be expressed by a number of bits of the index, and the nodes are preferably stored at only even or only odd indices of the table. In such case, a free list of nodes is preferably generated from an array of pairs of counts and indices to identify the available nodes. Additional table structures can further be provided to enhance data arrangement and searching functions.

Abstract: A data storage system and associated method are provided wherein a policy engine continuously collects qualitative information about a network load to the data storage system in order to dynamically characterize the load and continuously correlates the load characterization to a command queue depth of data transfer requests.

Abstract: A plurality of data storage devices are arranged to form a multi-device array space, and a controller controls access to the array space. The controller is configured to index sets of operational performance data from the plurality of data storage devices into a unified data log. The controller further detects a failure trend of one or more data storage devices by analyzing at least one of a vertical block of data and a horizontal block of data in the unified data log. The vertical data block of data is associated with one of the data storage devices at a plurality of indices. The horizontal block of data is associated with a plurality of the data storage devices at an index.

Abstract: As apparatus and associated method for a dual active-active array storage system with a first controller with top level control of a first memory space and a second controller with top level control of a second memory space different than the first memory space. A seek manager residing in only one of the controllers defines individual command profiles derived from a combined list of data transfer requests from both controllers. A policy engine continuously collects qualitative information about a network load to both controllers to dynamically characterize the load, and governs the seek manager to continuously correlate each command profile in relation to the load characterization.

Abstract: A data storage system and associated method are provided wherein a policy engine continuously collects qualitative information about a network load to the data storage system in order to dynamically characterize the load and continuously correlates the load characterization to the content of a command queue of transfer requests for writeback commands and host read commands, selectively limiting the content with respect to writeback commands to only those transfer requests for writeback data that are selected on a physical zone basis of a plurality of predefined physical zones of a storage media.

Abstract: A data storage system and associated method are provided wherein a policy engine continuously collects qualitative information about a network load to the data storage system in order to dynamically characterize the load and continuously correlates the load characterization to a command queue depth of data transfer requests.

Abstract: A data storage system and associated method implement a HASTE with a policy engine that continuously collects qualitative information about a network load to the data storage system in order to dynamically characterize the load, and continuously correlates a command profile to a data storage device of the data storage system in relation to the characterization.

Abstract: Apparatus and method for command queue management of back watered requests. A selected request is released from a command queue, and further release of requests from the queue is interrupted when a total number of subsequently completed requests reaches a predetermined threshold.

Abstract: A plurality of data storage devices are arranged to form a multi-device array space, and a controller controls access to the array space. The controller is configured to index sets of operational performance data from the plurality of data storage devices into a unified data log. The controller further detects a failure trend of one or more data storage devices by analyzing at least one of a vertical block of data and a horizontal block of data in the unified data log. The vertical data block of data is associated with one of the data storage devices at a plurality of indices. The horizontal block of data is associated with a plurality of the data storage devices at an index.