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 distributed storage network (DSN) includes a user device and a plurality of DSN memories, wherein each of the DSN memories includes a plurality of storage units. The user device includes at least one network interface to the plurality of DSN memories and at least one processing module that is operable to determine one of the plurality of DSN memories for storing a data object based on a comparison of one or more storage requirements of the data object and one or more DSN attributes of the plurality of DSN memories.

Abstract: A distributed storage network (DSN) includes a user device and a plurality of DSN memories, wherein each of the DSN memories includes a plurality of storage units. The user device includes at least one network interface to the plurality of DSN memories and at least one processing module that is operable to determine one of the plurality of DSN memories for storing a data object based on a comparison of one or more storage requirements of the data object and one or more DSN attributes of the plurality of DSN memories.

Abstract: A method for writing a set of encoded data slices to memory of a dispersed storage network (DSN) begins by a processing module identifying an encoded data slice of the set of encoded data slices for a redundant write operation to produce an identified encoded data slice. The method continues with the processing module generating a set of first write requests regarding the set of encoded data slices less the identified encoded data slice and generating a set of second write requests regarding the identified encoded data slice. The method continues with the processing module sending the set of first write requests to storage units of the DSN and sending the set of second write requests to a set of storage units of the DSN, where each storage unit of the set of storage units is sent a corresponding one of the set of second write requests.

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 a storage unit receiving a respective write request of a first set of write requests, wherein the first set of write requests functions as a write lock request. The method further includes the storage unit determining whether the storage unit has writing of the data object currently locked. The method further includes the storage unit sending a write lock response regarding the data object. The method further includes the storage unit, when a number of write lock responses indicate a write lock of the data object for the computing device and the number is equal to or exceeds a write lock response threshold, receive respective write requests from each set of a plurality of sets of write requests, wherein the plurality of sets of write requests includes write requests for remaining sets of encoded data slices of the plurality of sets of encoded data slices.

Abstract: A method includes sending a set of check request messages to a set of storage units. A first check request message of the set of check request messages includes a first group of slice names that includes a first slice name from each of a plurality of sets of slice names, and the plurality of sets of slices names corresponds to a plurality of sets of encoded data slices. The method further includes receiving, by a first storage unit, the first check request message, determining a first group of slice information, and sending first check response message, where the first check response message includes the first group of slice information. The method further includes interpreting the first check response message in light of the first group of slice names to identify one or more encoded data slices of the plurality of sets of encoded data slices in need of rebuilding.

Abstract: A method for generating virtual dispersed storage network (DSN) addresses includes dispersed storage error encoding a data segment of a data object to produce a set of encoded data slices of a plurality of sets of encoded data slices of the pluralities of sets of encoded data slices. The method further includes generating, for each encoded data slice of the set of encoded data slices, a virtual DSN address having a slice name that includes a vault identifier, a slice index, a data object identifier, and a data segment identifier. The method further includes obtaining a mapping of a vault to a set of storage units of the DSN, wherein the mapping indicates how the set of encoded data slices are to be stored. The method further includes outputting the set of encoded data slices to the set of storage units in accordance with the mapping.

Abstract: A method begins with storage units receiving a request to transfer a copy of a set of encoded data slices from two or more source virtual storage vaults to a destination virtual storage vault. The method continues with each storage unit obtaining a slice transfer map and determining whether the storage unit supports one of the two or more source virtual storage vaults. For each supporting storage unit, the method continues with each supporting storage unit determining, based on the slice transfer map, a sub-set of encoded data slices of the set of encoded data slices that is stored within the one of the two or more source virtual storage vaults by the supporting storage unit. The method continues with the supporting storage unit sending the sub-set of encoded data slices to a corresponding storage unit that is supporting the destination virtual storage vault.

Abstract: A method includes receiving a request to retrieve a data object. The method further includes identifying an index file based on the search attribute. The method further includes entering a loop that includes: determining an address for a current index file; retrieving encoded data slices based on the address; decoding the encoded data slices to reproduce the current index file; determining whether the current index file includes the address for the data object; when the current index file does not include the address for the data object: identifying the other index file based on the search attribute; and repeating the loop for the other index file; and when the current index file includes the address for the data object, exiting the loop. The method further includes retrieving encoded data slices based on the address. The method further includes decoding the encoded data slices to recapture the data object.

Abstract: A method begins by a processing module of a computing device receiving a most current revision value for a data element, where a revision value for the data element is generated based on a current time of a storing device. The method continues with the processing module generating a new revision value for a currently revised version of the data element based on a current time of the computing device and comparing the current time of the new revision value with the current time of the most current revision value. When the current time of the new revision value precedes the current time of the most current revision value, the method continues with the processing module adjusting the new revision value to produce an adjusted revision value and facilitating storage of the currently revised version of the data element having the adjusted revision value.

Abstract: A method begins by a processing module of a computing device receiving a most current revision value for a data element, where a revision value for the data element is generated based on a current time of a storing device. The method continues with the processing module generating a new revision value for a currently revised version of the data element based on a current time of the computing device and comparing the current time of the new revision value with the current time of the most current revision value. When the current time of the new revision value precedes the current time of the most current revision value, the method continues with the processing module adjusting the new revision value to produce an adjusted revision value and facilitating storage of the currently revised version of the data element having the adjusted revision value.

Abstract: An efficient data deduplication method for use in a dispersed storage network (DSN). After a data object is received for storage in the DSN, it is determined whether a substantially identical data object has previously been encrypted and stored. The determination may be made, for example, by comparing an encryption key reference value relating to the data object to key reference information stored in DSN memory. If not detected, the data object is encrypted using an encryption key based on the data object. The encrypted data object is then compressed and stored. The encryption key and a key reference value are also stored as encoded key slices in DSN memory. If the data object was previously stored, it is encrypted using a retrieved encryption key that is substantially identical to the data object. The data object may then be compressed for storage using a pattern based data compression function.

Abstract: A method includes generating a plurality of segment allocation tables (SATs) for pluralities of sets of encoded data slices. For a first SAT, the method further includes dispersed storage error encoding the first SAT to produce a first set of encoded SAT slices. The method further includes generating a first source name for the first plurality of sets of encoded data slices and the first SAT based on an object identifier associated with the data object. The method further includes generating, based on the first source name, a first plurality of sets of slices names for the first plurality of sets of encoded data slices and the first set of encoded SAT slices. The method further includes outputting, based on the first plurality of sets of slices names, the first plurality of sets of encoded data slices and the first set of encoded SAT slices to storage units.

Abstract: A method begins by a dispersed storage (DS) processing module receiving access requests, processing data set requests and issuing access responses. The method continues by monitoring slice access requests to generate access records by either storing time stamped access records indicating identities of slices requested by a timestamp or by commonality of slice names. The method continues with determining a correlation of two or more slice access based on the access records when a correlation is greater than a correlation threshold and identifying two or more slices for co-location. The method continues when the two or more slices are not co-located by selecting one or more of the two or more slices for migration to a common memory device.

Abstract: A method begins by a processing module receiving a dispersed storage network (DSN) access request accessing DSN memory regarding a set of encoded data slices, selecting a local DSN directory or a global DSN directory to produce a selected DSN directory, identifying an entry of the selected DSN directory regarding the set of encoded data slices to produce an identified entry, and accessing the DSN memory regarding the set of encoded data slices. The method continues with the processing module determining whether to update one or more of the local DSN directory and the global DSN directory based on the accessing the DSN memory and when the one or more of the local DSN directory and the global DSN directory is to be updated, updating the one or more of the local DSN directory and the global DSN directory in accordance with the accessing the DSN memory.

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 begins by a set of distributed storage and task (DST) execution units receiving a set of partial tasks and data, where a partial task of the set of partial tasks includes a common task and a unique partial sub-task. The method continues with the set of DST execution units executing the common task on the data to produce a set of preliminary partial results. The method continues with a first DST execution unit of the set of DST execution units generating first interim data based on the at least some of the set of preliminary partial results. The method continues with the first DST execution unit executing a first unique partial sub-task on at least one of a first portion of the data and the first interim data to produce a first partial result.

Abstract: A method begins by a dispersed storage (DS) processing module monitoring processing status of a plurality of pending dispersed storage network (DSN) access requests, where less than a desired number of DS units have favorably responded to a set of access requests. The method continues with the DS processing module interpreting the processing status of the plurality of pending DSN access requests to detect a processing anomaly. The method continues with the DS processing module reprioritizing further processing of at least one of the plurality of pending DSN access requests having the processing anomaly and another one or more of the plurality of pending DSN access requests. The method continues with the DS processing module sending notice of the reprioritized further processing to one or more DS units.

Abstract: A method includes a computing device sending write request messages to storage units. For instance, a first write request that includes a first group of slice payloads for first encoded data slices and their corresponding revision levels is sent to a first storage unit. The method further includes the first storage unit processing the first write request to include a group of status messages for the first encoded data slices regard revision level status. The method further includes the computing device processing the first write response message to flag the encoded data slice having a revision issue for a rollback message and flag encoded data slices not having a revision issue for a write commit message.