Handling storage unit failure in a dispersed storage network

A processing system of a dispersed storage (DS) failure detection unit comprises:

• at least one processor;
• a memory that stores operational instructions, that when executed by the at least one processor cause the processing system to:
• generate a plurality of storage unit weights corresponding to a plurality of storage units;
• generate a plurality of storage set weights corresponding to a plurality of storage sets, wherein each of the plurality of storage sets includes a subset of the plurality of storage units, and wherein each of the plurality of storage set weights is based on the storage unit weights of the corresponding subset of storage units;
• identify one of the plurality of storage units that meets a weight-adjustment trigger condition, and generate a new storage unit weight for the identified one of the plurality of storage units in response;
• facilitate a first data migration within a first one of the plurality of storage sets that includes the identified one of the plurality of storage units based on the plurality of storage unit weights, wherein the first data migration includes transferring data slices stored in the identified one of the plurality of storage units to at least one other storage unit in the first one of the plurality of storage sets;
• identify a failing set of storage units in a second one of the plurality of storage sets that meet the weight-adjustment trigger condition;
• determine that a number of the identified storage units in the failing set compares favorably to a failure threshold number, and generate a new storage set weight for the second one of the plurality of storage sets in response;
• and
• facilitate a second data migration based on the plurality of storage set weights, wherein the second data migration includes transferring data slices stored in the subset of storage units of the second one of the plurality of storage sets to storage units in at least one other storage set.

A non-transitory computer readable storage medium comprises:

• at least one memory section that stores operational instructions that, when executed by a processing system of a dispersed storage network (DSN) that includes a processor and a memory, causes the processing system to:
• generate a plurality of storage unit weights corresponding to a plurality of storage units;
• generate a plurality of storage set weights corresponding to a plurality of storage sets, wherein each of the plurality of storage sets includes a subset of the plurality of storage units, and wherein each of the plurality of storage set weights is based on the storage unit weights of the corresponding subset of storage units;
• identify one of the plurality of storage units that meets a weight-adjustment trigger condition, and generate a new storage unit weight for the identified one of the plurality of storage units in response;
• facilitate a first data migration within a first one of the plurality of storage sets that includes the identified one of the plurality of storage units based on the plurality of storage unit weights, wherein the first data migration includes transferring data slices stored in the identified one of the plurality of storage units to at least one other storage unit in the first one of the plurality of storage sets;
• identify a failing set of storage units in a second one of the plurality of storage sets that meet the weight-adjustment trigger condition;
• determine that a number of the identified storage units in the failing set compares favorably to a failure threshold number, and generate a new storage set weight for the second one of the plurality of storage sets in response;
• and
• facilitate a second data migration based on the plurality of storage set weights, wherein the second data migration includes transferring data slices stored in the subset of storage units of the second one of the plurality of storage sets to storage units in at least one other storage set.