Determining slices to rebuild from low-level failures

• US 10,530,862 B2
• Filed: 12/20/2017
• Issued: 01/07/2020
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Isely, Michael Christian, Resch, Jason K.
• Primary Examiner(s): Alphonse, Fritz
• Application Number:
  US15/848,196
• Publication Number:
  US 20180115606A1
• Time in Patent Office: 748 Days
• Field of Search: 714759, 714762, 714760
• CPC Class Codes: G06F 11/00 Error detection; Error correction; Monitoring error detection, correction or monitoring in information storage based on relative movement between record carrier and transducer G11B20/18; monitoring, i.e. supervising the progress of recording or reproducing G11B27/36; in static stores G11C29/00
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/3761 using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A distributed storage network (DSN) includes multiple distributed storage task execution (DST EX) units, each employing multiple memory portions to store encoded data slices. A DST EX unit detects a physical storage failure associated with an affected memory portion of a storage unit included in the DST EX unit. A memory portion identifier of the affected memory portion is used to identify a range of impacted encoded data slices associated with the affected memory portion, and in some cases specific encoded data slices within that range. The DST Ex unit issues rebuilding information to the DSN. The rebuilding information includes at least one identifier associated with at least one impacted encoded data slice included in the range of impacted encoded data slices.

Claims

1. A method for use in a distributed storage network (DSN) including a plurality of distributed storage task execution (DST EX) units, each of the plurality of DST EX units employing a plurality of memory portions to store encoded data slices, the method comprising:

detecting, by a DST EX unit, a physical storage failure associated with an affected memory portion of a storage unit included in the DST EX unit;

determining, by the DST EX unit, a memory portion identifier of the affected memory portion;

identifying, by the DST EX unit, at least a range of impacted encoded data slices associated with the affected memory portion; and

issuing, by the DST EX unit, rebuilding information to the DSN, the rebuilding information includes at least one identifier associated with at least one impacted encoded data slice included in the at least a range of impacted encoded data slices.

2. The method of claim 1, further comprising:

identifying slice names of specific impacted encoded data slices associated with the affected memory portion.

3. The method of claim 1, further comprising:

facilitating performance of an integrity check, the integrity check verifying that at least one impacted encoded data slice included in the at least a range of impacted encoded data slices is actually corrupted.

4. The method of claim 1, wherein identifying at least a range of impacted encoded data slices includes:

accessing a physical location to slice name table utilizing the memory portion identifier.

5. The method of claim 1, further comprising:

generating the rebuilding information to include slice names of each impacted encoded data slices.

6. The method of claim 1, further comprising:

rebuilding the at least one impacted encoded data slice to generate a rebuilt encoded data slice; and

storing the rebuilt encoded data slice in another memory portion of the DST EX unit.

7. The method of claim 1, further comprising:

issuing the rebuilding information to at least one of a rebuilding module, an integrity processing unit, another DST EX unit, or a DST processing unit.

8. A distributed storage task execution (DST EX) unit for use in a distributed storage network (DSN), the DST EX unit comprising:

a processor and associated memory;

one or more distributed storage (DS) memories coupled to the processor and associated memory, the one or more DS memories including a plurality of memory portions used by the processor and associated memory to store encoded data slices;

the processor and associated memory configured to;

detect a physical storage failure associated with an affected memory portion of the one or more DS memories;

determine a memory portion identifier of the affected memory portion;

identify at least a range of impacted encoded data slices associated with the affected memory portion; and

issue rebuilding information to the DSN, the rebuilding information includes at least one identifier associated with at least one impacted encoded data slice included in the at least a range of impacted encoded data slices.

9. The distributed storage task execution (DST EX) unit of claim 8, the processor and associated memory further configured to:

identify slice names of specific impacted encoded data slices associated with the affected memory portion.

10. The distributed storage task execution (DST EX) unit of claim 8, the processor and associated memory further configured to:

facilitate performance of an integrity check, the integrity check verifying that at least one impacted encoded data slice included in the at least a range of impacted encoded data slices is actually corrupted.

11. The distributed storage task execution (DST EX) unit of claim 8, the processor and associated memory further configured to:

identify at least a range of impacted encoded data slices by accessing a physical location to slice name table utilizing the memory portion identifier.

12. The distributed storage task execution (DST EX) unit of claim 8, the processor and associated memory further configured to:

generate the rebuilding information to include slice names of each impacted encoded data slices.

13. The distributed storage task execution (DST EX) unit of claim 8, the processor and associated memory further configured to:

rebuild the at least one impacted encoded data slice to generate a rebuilt encoded data slice; and

store the rebuilt encoded data slice in another memory portion.

14. The distributed storage task execution (DST EX) unit of claim 8, the processor and associated memory further configured to:

issue the rebuilding information to at least one of a rebuilding module, an integrity processing unit, another DST EX unit, or a DST processing unit.

15. A distributed storage network (DSN) comprising:

a set of distributed storage task execution (DST EX) units, at least one DST EX unit included in the set of DST EX units including;

a processor and associated memory;

one or more distributed storage (DS) memories coupled to the processor and associated memory, the one or more DS memories including a plurality of memory portions used by the processor and associated memory to store encoded data slices;

the processor and associated memory configured to;

detect a physical storage failure associated with an affected memory portion of the one or more DS memories;

determine a memory portion identifier of the affected memory portion;

identify at least a range of impacted encoded data slices associated with the affected memory portion; and

issue rebuilding information to the DSN, the rebuilding information includes at least one identifier associated with at least one impacted encoded data slice included in the at least a range of impacted encoded data slices.

16. The distributed storage network (DSN) of claim 15, the processor and associated memory further configured to:

identify slice names of specific impacted encoded data slices associated with the affected memory portion.

17. The distributed storage network (DSN) of claim 15, the DSN further including:

an integrity processing unit coupled to the at least one DST EX unit; and

the DST EX unit configured to verify that at least one impacted encoded data slice included in the at least a range of impacted encoded data slices is actually corrupted by requesting the integrity processing unit to perform an integrity check.

18. The distributed storage network (DSN) of claim 15, the processor and associated memory further configured to:

identify at least a range of impacted encoded data slices by accessing a physical location to slice name table utilizing the memory portion identifier.

19. The distributed storage network (DSN) of claim 15, the processor and associated memory further configured to:

generate the rebuilding information to include slice names of each impacted encoded data slices.

20. The distributed storage network (DSN) of claim 15, DSN further including:

a rebuilding module coupled to the at least one DST EX unit, the rebuilding module configured to rebuild encoded data slices on behalf of the at least one DST EX unit;

the at least one DST EX unit configured to;

issue the rebuilding information to the rebuilding module;

receive a rebuilt encoded data slice from the rebuilding module; and

store the rebuilt encoded data slice in another memory portion.