Partial rebuilding techniques in a dispersed storage unit

A computer readable storage medium comprises:

• at least one memory section that stores operational instructions that, when executed by one or more processing modules of a dispersed storage network (DSN) that include a processor and a memory, causes the one or more processing modules to:
• receive a data object for storage in a set of storage units of the DSN;
• dispersed storage error encode at least one data segment of the data object to produce a set of encoded data slices that includes an information dispersal algorithm (IDA) width number of encoded data slices, wherein the IDA width number is at least twice the number of storage units in the set of storage units;
• facilitate storage of the set of encoded data slices in the set of storage units, where at least two encoded data slices of the set of encoded data slices are stored in each of the storage units of the set of storage units;
• detect a storage error indicating that an encoded data slice of the set of encoded data slices is an error slice;
• request, in response to the storage error, a partial threshold number of partial encoded data slices for select encoded data slices of the set of encoded data slices;
• perform a partial encoding function on locally stored encoded data slices of the select encoded data slices to produce a group of partial encoded data slices;
• combine a respective group of partial encoded data slices to produce respective partial encoded data slice responses;
• receive a partial threshold number of partial encoded data slice responses;
• combine the partial threshold number of partial encoded data slice responses to produce a rebuilt encoded data slice corresponding to the error slice;
• and
• facilitate storage of the rebuilt encoded data slice in the set of storage units.

A computing device of a dispersed storage network (DSN), the computing device comprises:

• a network interface;
• a memory comprising instructions;
• and
• one or more processing modules in communication with the memory, wherein the one or more processing modules execute the instructions to:
• receive a data object for storage in a set of storage units of the DSN;
• dispersed storage error encode at least one data segment of the data object to produce a set of encoded data slices that includes an information dispersal algorithm (IDA) width number of encoded data slices, wherein the IDA width number is at least twice the number of storage units in the set of storage units;
• facilitate storage of the set of encoded data slices in the set of storage units, where at least two encoded data slices of the set of encoded data slices are stored in each of the storage units of the set of storage units;
• detect a storage error indicating that an encoded data slice of the set of encoded data slices is an error slice;
• request, in response to the storage error, a partial threshold number of partial encoded data slices for select encoded data slices of the set of encoded data slices, wherein a partial encoded data slice is generated by combining a plurality of slices generated by a partial encoding function;
• receive, via the network interface, a partial threshold number of partial encoded data slice responses;
• combine the partial threshold number of partial encoded data slice responses to produce a rebuilt encoded data slice corresponding to the error slice;
• and
• facilitate, via the network interface, storage of the rebuilt encoded data slice in the set of storage units.