A processing system of a storage network operates by: sending, to at least one storage unit of the 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 data, wherein the data is coded 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 encoded data slices that is required to decode the data; receiving, at the at least one processing circuit and from the at least one storage unit, a first subset of the set of encoded data slices, wherein at least one missing encoded data slice was not included in the first subset and wherein a number of encoded data slices in the first subset is less than the read threshold number; generating, via the at least one processing circuit, at least one rebuilt encoded data slice corresponding to the at least one missing encoded data slice utilizing locally decodable redundancy data, wherein the locally decodable redundancy data corresponds to a second subset of the set of encoded data slices that includes the at least one missing encoded data slice and wherein the locally decodable redundancy data is stored locally to the processing circuit; and recovering, via the at least one processing circuit, the data based on the at least one rebuilt encoded data slice and the first subset.

A storage device may include a storage medium configured to store data of an external device; and a storage controller configured to control an operation of the storage medium. The storage controller is configured to receive a storage request for the data and an external trust level of the data from the external device, determine an internal trust level of the data as one of a plurality of internal trust levels based on the external trust level in consideration of a status of the storage medium, group the data into unit data having an arbitrary size corresponding to the determined internal trust level, generate parity information corresponding to the determined internal trust level based on the grouped data, and control an operation of storing the grouped data and the parity information in the storage medium.

A storage network is operable to obtain a first subset of a set of encoded data slices, where the set of encoded data slices correspond to data that is coded in accordance with dispersed error coding parameters that include a read threshold number, and where the read threshold number is a number of the set of encoded data slices that is required to decode the data. Based on the number of encoded data slices in the first subset being less than the read threshold number, at least one rebuilt encoded data slice corresponding to at least one additional encoded data slice of the set of data slices not included in the first subset of the set of encoded data slices is generated utilizing locally decodable redundancy data. The data is recovered based on the at least one rebuilt encoded data slice and the first subset.