Method and apparatus for storage integrity processing based on error types in a dispersed storage network

1. A method for execution by one or more processing modules, the method comprises:

selecting an encoded data slice with an error for rebuilding to produce an identified data slice, wherein the identified data is one of a plurality of encoded data slices generated from a data segment using an error encoding dispersal function; and

rebuilding the identified data slice in response to a type of the error.

2. The method of claim 1 , wherein the rebuilding the identified data slice comprises:

when the type of the error includes a temporary error, waiting a predetermined time period;

after the predetermined time period, determining whether the error still exists; and

when the error still exists after the predetermined time period, rebuilding the identified data slice.

3. The method of claim 1 , wherein the rebuilding the identified data slice comprises:

when the type of the error includes a temporary error, scanning the plurality of encoded data slices to determine a number E of the plurality of encoded data slices with an associated error;

when the number E of the plurality of encoded data slices with an associated error compares unfavorably to a threshold, rebuilding the encoded data slice; and

when the number E of the plurality of encoded data slices with an associated error compares favorably to the threshold, waiting a predetermined time period before rebuilding the identified encoded data slice.

4. The method of claim 3 , wherein the threshold equals a number X of the plurality of encoded data slices less a number T of the plurality of encoded data slices needed to reconstruct the data segment based on the error coding dispersal function.

5. The method of claim 1 , wherein the rebuilding the identified data slice comprises:

retrieving at least a number T of the plurality of encoded data slices, wherein the number T corresponds to a number of the plurality of encoded data slices needed to reconstruct the data segment based on the error coding dispersal function;

reconstructing the data segment from at least the number T of the plurality of encoded data slices to produce a reconstructed data segment; and

generating a second plurality of encoded data slices from the reconstructed data segment based on the error coding dispersal function, wherein the second plurality of encoded data slices includes a rebuilt encoded data slice corresponding to the identified data slice.

6. The method of claim 1 further comprising:

determining the type of the error to be at least one of: a slice failure, a storage unit failure, and a site failure.

7. The method of claim 1 , wherein the rebuilding the identified data slice comprises:

determining the type of the error to be a slice failure;

when the slice failure includes a data corruption error, rebuilding the identified data slice;

when the slice failure includes a version update error, rebuilding the identified data slice; and

when the slice failure includes a missing slice error, waiting a predetermined time period to determine whether the missing slice error is corrected during the predetermined time period without rebuilding.

8. The method of claim 1 , wherein the rebuilding the identified data slice comprises:

determining the type of the error to be a storage unit failure, wherein the identified data slice is stored on a storage unit with the storage unit failure; and

when the storage unit failure is a temporary outage, waiting a predetermined time period to determine whether the storage unit failure is corrected during the predetermined time period without rebuilding.

9. The method of claim 1 , wherein the rebuilding the identified data slice comprises:

determining the type of the error to be a site failure, wherein the identified data slice is stored on a storage unit at a site with the site failure; and

when the site failure is a temporary outage, waiting a predetermined time period to determine whether the site failure is corrected during the predetermined time period without rebuilding.

10. The method of claim 1 , further comprising:

periodically scanning an address range of encoded data slices stored in one or more storage units, wherein the plurality of encoded data slices has addresses within the address range; and

determining whether one of the encoded data slices within the address range has an associated error.

11. The method of claim 1 , further comprising:

scanning the plurality of encoded data slices, wherein the plurality of encoded data slices is stored in one or more storage units; and

determining whether one of the plurality of encoded data slices has an associated error.

12. A storage integrity system in a dispersed storage network, comprising:

at least one network interface to the dispersed storage network; and

at least one processing module that is operable to:

identify an encoded data slice with an error for rebuilding to produce an identified data slice, wherein the identified data is one of a plurality of encoded data slices generated from a data segment using an error encoding dispersal function; and

rebuild the identified data slice in response to a type of the error.

13. The system of claim 12 , wherein the at least one processing module is further operable to:

when the type of the error includes a temporary error, waiting a predetermined time period;

after the predetermined time period, determining whether the error still exists; and

when the error still exists after the predetermined time period, rebuilding the identified data slice.

14. The system of claim 12 , wherein the at least one processing module is further operable to:

when the type of the error includes a temporary error, scanning the plurality of encoded data slices to determine a number E of the plurality of encoded data slices with an associated error;

when the number E of the plurality of encoded data slices with an associated error compares unfavorably to a threshold, rebuilding the encoded data slice; and

when the number E of the plurality of encoded data slices with an associated error compares favorably to the threshold, waiting a predetermined time period before rebuilding the identified encoded data slice.

15. The system of claim 14 , wherein the threshold equals a number X of the plurality of encoded date slices less a number T of the plurality of encoded data slices needed to reconstruct the data segment based on the error coding dispersal function.

16. The system of claim 12 , wherein the at least one processing module is further operable to:

determine the type of the error to be a slice failure;

when the slice failure includes a data corruption error, rebuild the identified data slice;

when the slice failure includes a version update error, rebuild the identified data slice; and

when the slice failure includes a missing slice error, determine whether the missing slice error is corrected during a predetermined time period before rebuilding.

17. The system of claim 12 , wherein the at least one processing module is further operable to:

determine the type of the detected error to be a storage unit failure, wherein the identified data slice is stored on a storage unit with the storage unit failure; and

when the storage unit failure is a temporary outage, determine whether the storage unit failure is corrected during a predetermined time period before rebuilding.

18. The system of claim 12 , wherein the at least one control unit is further operable to:

determine the type of the detected error to be a site failure, wherein the identified data slice is stored on a storage unit at a site with the site failure; and

when the site failure is a temporary outage, determine whether the site failure is corrected during a predetermined time period before rebuilding.

19. The system of claim 12 , further comprising:

at least one scanning agent operable to:

periodically scan an address range of encoded data slices stored in one or more storage units, wherein the plurality of encoded data slices has addresses within the address range; and

determine whether one of the encoded data slices within the address range has an associated error.

20. The system of claim 12 , further comprising:

at least one scanning agent operable to:

scan the plurality of encoded data slices, wherein the plurality of encoded data slices is stored in one or more storage units; and

determine whether one of the plurality of encoded data slices has an associated error.