Abstract: A storage controller identifies a storage division comprising unreadable data. In response, the storage controller relocates readable data (if any) from the identified storage division. The storage controller may be further configured to associate the unreadable data with a logical address, and to record persistent metadata to indicate that the logical address is mapped to unreadable, corrupt data. The storage controller may clear the corruption indicator from the logical address. The logical address may be cleared in response to determining that the unreadable data is invalid and/or available from another source.

Abstract: A storage controller identifies a storage location within a storage division that corresponds to a high error rate. In response, the storage controller may refresh data stored on the storage division by relocating data from the storage division and/or initializing (e.g., erasing) the storage division. In some embodiments, the storage division is selectively refreshed by relocating data from the storage location(s) having high error rates, while deferring a full relocation of other data from the storage division. The storage division may be selectively refreshed based on reliability characteristics of the storage division, such as the remaining data retention time calculated for the storage division.

Abstract: A storage system implements a sparse, thinly provisioned logical-to-physical translation layer. The storage system may perform operations to modify logical-to-physical mappings, including creating, removing, and/or modifying any-to-any and/or many-to-one mappings between logical identifiers and stored data (logical manipulation operations). The storage system records persistent metadata to render the logical manipulation (LM) operations persistent and crash-safe. The storage system may provide access to LM functionality through a generalized LM interface. Clients may leverage the LM interface to efficiently implement higher-level functionality and/or offload LM operations to the storage system.

Abstract: Embodiments are disclosed relating to garbage collecting storage blocks in a storage device. In one embodiment, data is selected for relocation from a storage block in a storage device during reclaiming of the storage block. The data may be selected based on metadata that identifies whether data is valid at a time when the reclaiming is initiated. In some embodiments, prior to relocating data from the storage block, the metadata is captured from a data structure that identifies whether data on the storage device is valid. In one embodiment, a determination of whether the selected data has become invalid due to other data that is stored during the reclaiming is made. In some embodiments, in response to determining that the selected data has become invalid, the selected data is specified as invalid in the data structure.

Abstract: A cache automation module detects the deployment of storage resources in a virtual computing environment and, in response, automatically configures cache services for the detected storage resources. The automation module may detect new storage resources by monitoring storage operations and/or requests, by use of an interface provided by virtualization infrastructure, and/or the like. The cache automation module may deterministically identify storage resources that are to be cached and automatically caching services for the identified storage resources.

Abstract: A compression manager generates a reduced-size data set for a page. The reduced-size data set is stored on a storage medium by a storage module, and unused portions of the page are identified and/or recorded by the storage module. The reduced-size data set may be generated by compressing the page. The reduced-size data set may be written in response to a request from a client, which provides a message that identifies the unused portion(s) of the page. The page may be stored in a file, and the unused portion may correspond to empty portion(s) within the file. The storage module may maintain an index to map the page to the reduced-size data set, such that portions of the page are unmapped. The storage capacity used by the page may correspond to the mapped portion of the page, and exclude portion(s) of the page that are unmapped.

Abstract: Apparatuses, methods, and computer program products are disclosed for determining read thresholds for a non-volatile memory device. A method includes obtaining soft read data for a storage cell of a non-volatile storage medium. A method includes determining a read voltage threshold or other configuration parameter for a storage cell based on soft read data. A method includes using a determined read voltage threshold or other configuration parameter to read data from a storage cell.

Abstract: Apparatuses, systems, methods, and computer program products are disclosed for error correction. A soft read module is configured to obtain soft read information for a cell of a non-volatile memory medium. The soft read information may indicate a likelihood that a data value for the cell is correct. A reliability module is configured to associate the cell with a log-likelihood ratio (LLR) mapping from a plurality of LLR mappings based on one or more reliability characteristics for a set of cells that includes the cell. An LLR map module is configured to determine an LLR value based on the soft read information by using the LLR mapping.

Abstract: Techniques are disclosed relating to storage device failover. In one embodiment, a plurality of storage devices are represented as cluster resources to a cluster resource manager that manages cluster resources on a plurality of cluster nodes. An indication may be received that a failover operation is requested with respect to one of the plurality of storage devices. In response to the indication, the cluster resource manager may initiate the failover operation. In some embodiments, the failover operation includes changing a first access state of the storage device and a second access state of another storage device. In such an embodiment, the storage device and the other storage device may be associated with a logical unit number. In some embodiments, the storage device is located within a first of the plurality of cluster nodes; the other storage device is located within a second of the plurality of cluster nodes.

Abstract: A storage layer may over-provision physical storage resources of a storage medium by reserving a portion of the full physical storage capacity of the storage medium for use as reserve capacity. The reserve capacity may be used to prevent write stall conditions and/or for grooming operations, such as storage recovery, refresh, and the like. A reserve module may be configured to adapt the reserve capacity in accordance with, inter alia, operating conditions on the storage layer. The reserve module may be configured to dynamically modify the storage capacity available through the storage layer. A cache layer configured to cache data of a backing store on the storage layer, may be configured to add and/or remove cache entries in response to changes in the reserve capacity.

Abstract: An aggregation module combines a plurality of logical address spaces to form a conglomerated address space. The logical address spaces comprising the conglomerated address space may correspond to different respective storage modules and/or storage devices. An atomic aggregation module coordinates atomic storage operations within the conglomerated address space, and which span multiple storage modules. The aggregation module may identify the storage modules used to implement the atomic storage request, assign a sequence indicator to the atomic storage request, and issue atomic storage requests (sub-requests) to the storage modules. The storage modules may be configured to store a completion tag comprising the sequence indicator upon completing the sub-requests issued thereto. The aggregation module may identify incomplete atomic storage requests based on the completion information stored on the storage modules.

Abstract: Apparatuses, systems, methods, and computer program products are disclosed for error correcting code (ECC) decoding. A score module is configured to assign a score to a variable node of low density parity check (LDPC) code decoder. The LDPC code decoder may include a plurality of variable nodes associated with a plurality of check nodes. The plurality of variable nodes may correspond to bits of a received code word. The score for the variable node may be based on a count of unsatisfied check nodes associated with the variable node. A variable node update module is configured to update the variable node based on the score. A check node update module is configured to update one or more of the check nodes based on the updated variable node.

Abstract: An apparatus, system, and method are disclosed for managing operations for data storage media. An adjustment module interrupts or otherwise adjusts execution of an executing operation on the data storage media. A schedule module executes a pending operation on the data storage media in response to adjusting execution of the executing operation. The pending operation comprises a higher execution priority than the executing operation. The schedule module finishes execution of the executing operation in response to completing execution of the pending operation.

Abstract: A storage layer presents logical address space of a non-volatile storage device. The storage layer maintains logical interfaces to the non-volatile storage device, which may include arbitrary, any-to-any mappings between logical identifiers and storage resources. Data may be stored on the non-volatile storage device in a contextual format, which includes persistent metadata that defines the logical interface of the data. The storage layer may modify the logical interface of data that is stored in the contextual format. The modified logical interface may be inconsistent with the existing contextual format of the data on the non-volatile storage media. The storage layer may provide access to the data in the inconsistent contextual format through the modified logical interface. The contextual format of the data may be updated to be consistent with the modified logical interface in a write out-of-place storage operation.

Abstract: Techniques are disclosed relating to writing data atomically to one or more recording media. In one embodiment, a request is received to perform an atomic write for a set of data. Responsive to the request, the set of data is written across a plurality of storage units including storing metadata at a dedicated location within at least one of the plurality of storage units. The metadata is usable to determine whether the writing completed successfully. In some embodiments, the request is received from an application that has been assigned an address range of the plurality of storage units. In such an embodiment, the address range is accessible to the application for storing data, and the dedicated location resides outside of the address range. In one embodiment, the metadata specifies an address range where the set of data was written and a sequence number.

Abstract: An atomic storage module may be configured to implement atomic storage operation directed to a first set of identifiers in reference to a second, different set of identifiers. In response to completing the atomic storage operation, the atomic storage module may move the corresponding data to the first, target set of identifiers. The move operation may comprise modifying a logical interface of the data. The move operation may further include storing persistent metadata configured to bind the data to the first set of identifiers.

Abstract: A storage layer is configured to implement efficient open-close consistency operations. Open close consistency may comprise preserving the original state of a file until the file is closed. The storage layer may be configured to clone a file in response to a file open request. Cloning the file may comprise referencing file data by two separate sets of identifiers. One set may be configured to reflect file modifications, and the other set may be configured to preserve the original state of the file. Subsequent operations configured to modify the file may be performed in reference to one of the sets of identifiers, while the storage layer provides access to the unmodified file through the other set of identifiers. Closing the file may comprise merging the sets of identifiers according to a merge policy.

Abstract: Apparatuses, systems, and methods are disclosed for managing non-volatile a medium. A method includes determining whether a first error correcting code (ECC) code word of a non-volatile storage device is correctable using a first error correcting code. A method includes determining whether a second ECC code word is correctable using a second error correcting code in response to determining that a first ECC code word is uncorrectable using a first error correcting code. A method includes adjusting one or more media parameters for accessing a non-volatile medium of a non-volatile storage device based on error information. Error information may include information from a decoder for a second error correcting code. Adjusting one or more media parameters may be in response to determining that a second ECC code word is correctable using a second error correcting code.

Abstract: Data is stored on a non-volatile storage media in a sequential, log-based format. The formatted data defines an ordered sequence of storage operations performed on the non-volatile storage media. A storage layer maintains volatile metadata, which may include a forward index associating logical identifiers with respective physical storage units on the non-volatile storage media. The volatile metadata may be reconstructed from the ordered sequence of storage operations. Persistent notes may be used to maintain consistency between the volatile metadata and the contents of the non-volatile storage media. Persistent notes may identify data that does not need to be retained on the non-volatile storage media and/or is no longer valid.

Abstract: An apparatus, system, and method are disclosed for managing a non-volatile storage medium. A storage controller receives a message that identifies data that no longer needs to be retained on the non-volatile storage medium. The data may be identified using a logical identifier. The message may comprise a hint, directive, or other indication that the data has been erased and/or deleted. In response to the message, the storage controller records an indication that the contents of a physical storage location and/or physical address associated with the logical identifier do not need to be preserved on the non-volatile storage medium.