A method for storing a data object includes identifying data segments of the data object. The method continues with generating key indexes for the data segments. For a data segment, the method continues with accessing data segment key information based on a corresponding key index of the plurality of key indexes to determine whether an encryption key has been generated for a similar data segment. When the encryption key has been generated for the similar data segment, the method continues with using the encryption key to encrypt the data segment to produce an encrypted data segment. The method continues with compressing the encrypted data segment to produce a compressed and encrypted data segment. The method continues with storing the compressed and encrypted data segment in a storage unit of a dispersed storage network (DSN).

A method for execution by a dispersed storage and task (DST) processing unit includes obtaining audit records for an audit object and determining when the audit object is complete. When the audit object is complete, aggregating the audit records of the audit object within the audit object by generating the audit object to include the audit records; generating identifier (ID) information and generating integrity information. Fields of the audit object are populated with the audit records, the ID information, and the integrity information and a name of the audit object is determined for storage of the audit object and the name of the audit object in a dispersed storage network (DSN).

To ensure that there is an elected manager among storage nodes of an erasure coding group (“ECG”), an ECG manager (“ECGM”) election process is periodically performed among available storage nodes that are configured with the software to perform the services of an ECGM. When a storage node is activated, an ECGM process of the storage node begins executing and is assigned a process identifier (“PID”). A storage node can utilize a service query framework to identify other available storage nodes and retrieve their ECGM PIDs. The storage node then selects a PID according to a criterion and elects the storage node corresponding to the selected PID to be the acting ECGM. This process is performed periodically, so even if the acting ECGM storage node fails, a new ECGM is eventually selected from the available storage nodes.

A method begins by a distributed storage (DS) processing module transmitting a set of requests to a set of DS units regarding a set of data elements and receiving a set of respective requests from the set of DS units. When the set of respective requests is in accordance with a current distributed task/data responsibility allocation period, the method continues with the DS processing module issuing a set of responses to the set of DS units. The method continues with the DS processing module receiving a set of respective responses from the set of DS units. When the set of received respective responses is in accordance with the current distributed task/data responsibility allocation period, the method continues with the DS processing module processing the set of received respective responses in accordance with the current distributed task/data responsibility allocation period to produce one of a set of results.

Methods and apparatus for selection of memory devices in a distributed storage network. In an example, a computing device receives a data object for storage and selects a set of storage nodes of a plurality of sets of storage nodes for storing the data object. Selection of the set of storage nodes includes determining storage attributes associated with each set of storage nodes of the plurality of sets of storage nodes. Selection of the set of storage nodes additionally includes determining a storage preference associated with the data object, and comparing the storage preference with the storage attributes of the plurality of sets of storage nodes to determine a best match. Following selection of a set of storage nodes, the computing device facilitates storage of the data object in the selected set of storage nodes.

Implementations relate to storing a data file in data storages. In some implementations, a method for storing a data file in n data storages includes dividing the data file into data file parts such that at least n−1 data file parts are equal in size, and for each n−1 data file part, combining the n−1 data file parts by XOR to obtain a first data file result. The method deranges the first data file result and combines each of n−2 data file parts of the n−1 data file parts and the deranged first data file result by XOR to obtain second data file results. The method combines the first data file result and the second data file results by XOR to obtain a third data file result, and stores each of the first, second and third data file results in one of the n data storages.

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.

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.

A method begins by a first computing device of a dispersed storage network (DSN) of a plurality of DSNs receiving a data segment for storage, encoding the data segment using a dispersed storage error encoding function to produce a set of encoded data slices, where each DSN of the plurality of DSNs utilizes the dispersed storage error encoding function, and generating a set of DSN addresses for the set of encoded data slices using a deterministic function. The method continues with a set of storage units of the DSN storing the set of encoded data slices using the set of DSN addresses. The method continues with storage units of the set of storage units and of another set of storage units of another DSN coordinating to store copies of encoded data slices of the set of encoded data slices in corresponding storage units of both sets of storage units.

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.