Abstract: A network storage system operates by: sending, to at least one storage unit of a storage network, at least one read request corresponding to at least a read threshold number of a set of encoded data slices to be retrieved, wherein the set of encoded data slices correspond to a data segment, wherein the data segment is codable in accordance with dispersed error coding parameters that include a write threshold number and the read threshold number, wherein the write threshold number is a number of encoded data slices in the set of encoded data slices and wherein the read threshold number is a number of the set of slices that is required to decode the data segment; receiving from the at least one storage unit, a first subset of encoded data slices of the set of encoded data slices, wherein the first subset of encoded data slices is missing at least one missing encoded data slice from the number of the set of slices that is required to decode the data segment and that was not received from the at least one storage

Abstract: A method for execution by a storage unit of a dispersed storage network (DSN) includes receiving a data slice for storage. A first bin that includes the data slice is generated and stored in a first location of a memory device of the storage unit, and a bin pointer that includes a reference to the first location is generated. A revision of the data slice is later received, and a second bin that includes the revised data slice is generated and stored in a second location of the memory device. A modified bin pointer is generated by editing the bin pointer to include a reference to the second location. A back pointer that references the first location is generated in response to commencing writing of the revised data slice. The back pointer is deleted in response to determining that the revised data slice has reached a finalized write stage.

Abstract: In various embodiments, a method is presented for execution by a processing circuit of a storage network device that includes a processor. The method comprises: receiving, via the processing circuit, a first subset of encoded data slices of a set of encoded data slices corresponding to a data segment; identifying, via the processing circuit, at least one missing encoded data slice of the first subset of slices that is required to decode the data segment; generating, via the processing circuit, at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data; and recovering, via the processing circuit, the data segment based on the at least one rebuilt encoded data slice and the first subset of encoded data slices.

Abstract: A computing device includes an interface configured to interface and communicate with a storage network, a memory that stores operational instructions, and a processing module operably coupled to the interface and memory such that the processing module, when operable within the computing device based on the operational instructions, is configured to perform various operations. A computing device receives a data access request for an encoded data slice associated with a data object, determines whether the encoded data slice is stored in the first memory and in response to a determination that the encoded data slice is not stored in the first memory, issues another data access request for the encoded data slice to a second memory, where the first memory includes access characteristics that are faster than the second memory. When a data access response including the encoded data slice is received from the second memory, a response including the encoded data slice is transmitted.

Abstract: Systems and methods for storing encoded data slices in a storage network involve generating a set of write slice requests relating to the encoded data slices, outputting the set of write slice requests to distributed storage units, receiving write slice responses and determining whether to retry storing the set of encoded data slices based on one or more of the write slice responses. Determining whether to retry storing the set of encoded data slices may involve determining whether less than a write threshold number of favorable responses were received, for example in a time period, and/or whether an unfavorable response was received. Determining whether to retry may also be based on receiving a slow or non-response. For purposes of retrying, the systems and methods may also determine whether to modify the write slice requests, for example by modifying a revision number.

Abstract: Methods and systems for compression of aging data during compaction are disclosed. A method includes: ingesting a plurality of data objects into a dispersed storage network (DSN); determining that a compaction threshold is met for a storage medium in the DSN; and compacting the storage medium, the compaction including, for each of the plurality of data objects: determining a number of times the data object has been compacted; in response to the number of times the data object has been compacted exceeding a predetermined threshold, compressing the data object and rewriting the compressed data object to a new area on a storage medium; and in response to the number of times the data object has been compacted not exceeding the predetermined threshold, rewriting the data object to the new area on the storage medium without compressing the data object.

Abstract: A storage unit operates by: receiving a write slice request, wherein the write slice request includes a plurality of encoded data slices and wherein the write slice request corresponds to a range; determining whether a write lock conflict exists based on the range; issuing an unfavorable write slice response when the write lock conflict is determined to exist; and when the write lock conflict is determined to not exist: initiating local storage of the plurality of encoded data slices; and issuing a favorable write slice response.

Abstract: A data object to be stored in one or more memories as a first set of encoded data segments is received at a storage processing module. An index to include an entry identifying the data object to be stored is updated, and storage of the data object is initiated. Initiating storage of the data object includes initiating storage of the first set of encoded data segments. A determination is made regarding whether storage of the data object to the one or more memories has been completed. If storage of the data object has been completed, the entry identifying the data object to be stored is removed from the index.

Abstract: A computing device includes an interface configured to interface and communicate with a dispersed storage network (DSN), a memory that stores operational instructions, and a processing module operably coupled to the interface and memory such that the processing module, when operable within the computing device based on the operational instructions, is configured to perform various operations. A computing device receives a data access request for an encoded data slice (EDS) associated with a data object. The computing device compares a slice name of the data access request with slice names stored within RAM. When the data access request slice name compares unfavorably with those stored slice names, the computing device transmits an empty data access response that includes no EDS to the other computing device without needing to access a hard disk drive (HDD) that stores EDSs. Alternatively, the computing device transmits a data access response that includes the EDS.

Abstract: A processor in a storage network operates by: receiving an access request for a data segment, wherein the data segment is encoded utilizing an error correcting information dispersal algorithm as a set of encoded data slices that are stored in a plurality of storage units of the storage network and wherein each encoded data slice of the set of encoded data slices includes a corresponding checksum of a plurality of checksums; retrieving, from the storage network, a subset of encoded data slices that includes a threshold number of encoded data slices of the set of encoded data slices; determining, based on ones of the plurality of checksums corresponding to the subset of encoded data slices, when the subset of encoded data slices includes at least one corrupted encoded data slice; retrieving from at least one of the plurality of storage units an addition number of encoded data slices required to generate a reconstructed data segment based on the subset of encoded data slices; generating the reconstructed data se

Abstract: A method for execution by a dispersed storage and task (DST) execution unit includes receiving a write slice request from a requesting entity, where the write slice request includes a plurality of encoded data slices and a corresponding plurality of slice names. The plurality of slice names are interpreted to produce a slice name range. Whether a write lock conflict exists is determined based on the slice name range. An unfavorable write slice response is issued to the requesting entity when the write lock conflict is determined to exist. When the write lock conflict is determined to not exist, local storage of the plurality of encoded data slices is initiated, a favorable write slice response is issued to the requesting entity, and the processing system indicates that the slice name range is not locked when completing the local storage of the plurality of encoded data slices.

Abstract: A distributed storage integrity system in a dispersed storage network includes a scanning agent and a control unit. The scanning agent identifies an encoded data slice that requires rebuilding, wherein the encoded data slice is one of a plurality of encoded data slices generated from a data segment using an error encoding dispersal function. The control unit retrieves at least a number T of encoded data slices needed to reconstruct the data segment based on the error encoding dispersal function. The control unit is operable to reconstruct the data segment from at least the number T of the encoded data slices and generate a rebuilt encoded data slice from the reconstructed data segment. The scanning agent is located in a storage unit and the control unit is located in the storage unit or in a storage integrity processing unit, a dispersed storage processing unit or a dispersed storage managing unit.

Abstract: A method includes: receiving, by a computing device, a data slice for storage in a dispersed storage network; predicting, by the computing device, a modification frequency associated with the data slice; and storing, by the computing device, the data slice in one of a first type zone of a data storage and a second type zone of the data storage based on the predicted modification frequency.

Abstract: A distributed storage integrity system in a dispersed storage network includes a scanning agent and a control unit. The scanning agent identifies an encoded data slice that requires rebuilding, wherein the encoded data slice is one of a plurality of encoded data slices generated from a data segment using an error encoding dispersal function. The control unit retrieves at least a number T of encoded data slices needed to reconstruct the data segment based on the error encoding dispersal function. The control unit is operable to reconstruct the data segment from at least the number T of the encoded data slices and generate a rebuilt encoded data slice from the reconstructed data segment. The scanning agent is located in a storage unit and the control unit is located in the storage unit or in a storage integrity processing unit, a dispersed storage processing unit or a dispersed storage managing unit.

Abstract: Methods and systems for use in a dispersed storage network to prioritize data rebuilding operations. In various examples, a device receives data loss information from a set of storage units. Based on the data loss information, data slice errors are detected regarding data stored by the storage units, and corresponding rebuild requests are issued to the storage units. The device also determines a rebuild rate based on a rate of rebuilding associated with the rebuild requests. The device further receives storage error information regarding errors associated with storage requests to the storage units and, based on the data loss information and storage error information, determines a data loss rate. The rebuild rate and the data loss rate are provided to the storage units for use in prioritizing the rebuild requests, such that when the rebuild rate compares unfavorably to the data loss rate, rebuild requests are prioritized over storage requests.

Abstract: Methods and systems for data retention in zone storage are disclosed. A method includes: ingesting, by a computing device, a plurality of data objects into a dispersed storage network (DSN); writing, by the computing device, the plurality of data objects to at least one zone on a storage medium in the DSN; determining, by the computing device, that a compaction threshold corresponding to the at least one zone on the storage medium in the DSN is met; determining, by the computing device, that a retention window corresponding to the at least one zone on the storage medium in the DSN has expired; and in response to determining that the retention window has expired, the computing device compacting the at least one zone on the storage medium in the DSN.

Abstract: A method for execution in a storage network begins by generating a set of query requests for each data segment of a plurality of data segments that includes a corresponding set of slice identifiers of a plurality of sets of slice identifiers, where each slice identifier of the corresponding set of slice identifiers includes a pillar index based on a vault affiliated with the plurality of data segments. The method continues by transmitting the set of query requests to a set of storage units affiliated with the storage network, receiving a plurality of sets of query responses from the storage units, obtaining a data identifier for slice location identification and generating a storage record that includes the data identifier and an identity of the set of storage units. The method then continues by facilitating migration of at least some encoded data slices associated with the plurality of sets of slice identifiers when the storage record compares unfavorably to a storage record requirement.

Abstract: A data segment is encrypted to produce an encrypted data segment, and a data tag associated with the data segment is generated. The encrypted data segment is encoded to generate a set of encoded data slices. At least a read-threshold number of encoded data slices are required to reconstruct the encrypted data segment. A set of write slice requests, which includes the set of encoded data slices and the data tag, is transmitted to a DSN memory. A determination is made, based on the data tag, whether a first encoded data slice of the set of encoded data slices is a duplicate of a second encoded data slice already stored within the DSN memory. If it is a duplicate, rather of storing the first encoded data slice, a reference to a location of the second encoded data slice is stored.

Abstract: A method for updating software of storage units of a set of storage units in a storage network. In an embodiment, each storage unit of the set of storage units determines a data slice storage status for data slices stored in the storage unit (e.g., by monitoring rebuilding messages relating to the data slices). A processing module of the storage network obtains the data slice storage status of the storage units of the set of storage units and determines whether to perform a software update to software of the storage units of the set of storage units. Determining whether to perform the software update includes determining, based on the data slice storage status of the storage units, whether a threshold number of storage units are associated with a favorable data slice storage status. In response to determining that a threshold number of storage units are associated with a favorable data slice storage status, the processing module indicates to perform the software update.

Abstract: A method begins by a processing module of a storage network analyzing storage network memory for a level of usability and based on the analyzing, selecting alternative memory available for receipt of encoded data slices stored in current memory, where a data object is segmented into a plurality of data segments and a data segment of the plurality of data segments is dispersed error encoded in accordance with dispersed error encoding parameters to produce a set of encoded data slices. The method continues with the processing module determining whether to move encoded data slices from current memory to alternative memory and based on a determination to move slices, allocating alternative memory. Finally, the processing module moves at least some encoded data slices from a current memory to alternate memory and updates a memory assignment mechanism for the at least some encoded data slices.