DISPERSED STORAGE RE-DISPERSION METHOD BASED ON A FAILURE

• US 20140359349A1
• Filed: 08/18/2014
• Published: 12/04/2014
• Est. Priority Date: 04/26/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Grube, Gary W., Markison, Timothy W., Resch, Jason K.
• Granted Patent: US 9,342,406 B2
• Time in Patent Office: Days
• US Class Current: 714/6.22
• CPC Class Codes: G06F 11/0727 in a storage system, e.g. in a DASD or network based storage system drivers for digital recording or reproducing units G06F3/06; circuits for error detection or correction within digital recording or reproducing units G11B20/18; 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], H04L67/1097
• CPC Class Codes: G06F 11/076 by exceeding a count or rate limit, e.g. word- or bit count limit
• CPC Class Codes: G06F 11/0763 by bit configuration check, e.g. of formats or tags
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: G06F 11/1008 in individual solid state devices G06F11/1004 takes precedence
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 21/60 Protecting data
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 21/70 Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• 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]
• CPC Class Codes: H04L 9/085 Secret sharing or secret splitting, e.g. threshold schemes
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

A method begins by identifying a storage unit of a set of storage units within a dispersed storage system as being likely to fail. The method continues by determining an approach for minimizing rebuilding the encoded data slices that are stored on an identified storage unit in an event of a failure of the identified storage unit. The approach is at least one approach option from a list of approach options that includes fostering new encoded data slices, replicating existing encoded data slices, and re-dispersing existing encoded data slices. The method continues by implementing the approach regarding the identified storage unit and when the identified storage unit fails, retrieving the encoded data slices that were stored on the identified storage unit based on the approach.

Claims

1. A method for execution by a computing device, the method comprises:

identifying a storage unit of a set of storage units within a dispersed storage system as being likely to fail;

determining an approach for minimizing rebuilding of encoded data slices stored on the identified storage unit in an event of a failure of the identified storage unit, wherein the approach is at least one approach option from a list of approach options, wherein the list of approach options includes fostering new encoded data slices, replicating existing encoded data slices, and re-dispersing existing encoded data slices;

implementing the approach regarding the identified storage unit; and

when the identified storage unit fails, retrieving the encoded data slices that were stored on the identified storage unit based on the approach.

2. The method of claim 1, wherein the identifying the storage unit comprises:

determining a detection of at least one of;

a maintenance cycle;

a network failure;

an error message;

a power indicator;

a weather indicator;

an earthquake indicator; and

an estimated future availability indicator.

3. The method of claim 1, wherein the retrieving the encoded data slices further comprises:

when the approach includes the fostering new encoded data slices;

sending a retrieval command to a foster storage unit that is storing the new encoded data slices; and

receiving the fostered encoded data slices.

4. The method of claim 1, wherein the retrieving the encoded data slices further comprises:

when the approach includes the replicating existing encoded data slices;

sending a retrieval command to a replication storage unit that is storing at least one of the replicated existing encoded data slices; and

receiving the at least one of the replicated existing encoded data slices.

5. The method of claim 1, wherein the retrieving the encoded data slices further comprises:

when the approach includes the re-dispersed existing encoded data slices;

sending a retrieval command to a set of re-dispersal storage units regarding a re-dispersed existing encoded data slice of the re-dispersed existing encoded data slices;

receiving a set of re-dispersed encoded data slices from the set of re-dispersal storage units; and

decoding, based on re-dispersal parameters, the set of re-dispersed encoded data slices to reproduce the re-dispersed existing encoded data slice.

6. The method of claim 1 further comprises:

when the approach includes the fostering new encoded data slices;

identifying a foster storage unit; and

instructing the computing device to send the new encoded data slices to the foster storage unit.

7. The method of claim 1 further comprises:

when the approach includes the replicating the existing encoded data slices;

identifying a replicating storage unit; and

instructing the identified storage unit to send a copy of at least some of the encoded data slices to the replicating storage unit.

8. The method of claim 1 further comprises:

when the approach includes the re-dispersing the existing encoded data slices;

determining re-dispersal parameters;

identifying a set of re-dispersal storage units; and

instructing the identified storage unit to;

dispersed storage error encode, in accordance with the re-dispersal parameters, one of the encoded data slices to create sub-slices; and

send the sub-slices to the set of re-dispersal storage units.

9. A computing device comprises:

an interface;

memory; and

a processing module operably coupled to the interface and the memory, wherein the processing module is operable to;

identify a storage unit of a set of storage units within a dispersed storage system as being likely to fail;

determine an approach for minimizing rebuilding of encoded data slices stored on the identified store unit in event of a failure of the identified storage unit, wherein the approach is at least one approach option from a list of approach options, wherein the list of approach options includes fostering new encoded data slices, replicating existing encoded data slices, and re-dispersing existing encoded data slices;

implement the approach regarding the identified storage unit; and

when the identified storage unit fails, retrieve, via the interface, the encoded data slices that were stored on the identified store unit based on the approach.

10. The computing device of claim 9, wherein the processing module in the identifying the storage unit further functions to:

determine a detection of at least one of;

a maintenance cycle;

a network failure;

an error message;

a power indicator;

a weather indicator;

an earthquake indicator; and

an estimated future availability indicator.

11. The computing device of claim 9, wherein the processing module in the retrieving the encoded data slices functions to:

when the approach includes the fostering new encoded data slices;

send a retrieval command to a foster storage unit that is storing the new encoded data slices; and

receive the fostered encoded data slices.

12. The computing device of claim 9, wherein the processing module in the retrieving the encoded data slices functions to:

when the approach includes the replicating existing encoded data slices;

send a retrieval command to a replication storage unit that is storing at least one of the replicated existing encoded data slices; and

receive the at least one of the replicated existing encoded data slices.

13. The computing device of claim 9, wherein the processing module in the retrieving the encoded data slices functions to:

when the approach includes the re-dispersed existing encoded data slices;

send a retrieval command to a set of re-dispersal storage units regarding a re-dispersed existing encoded data slice of the re-dispersed existing encoded data slices;

receive a set of re-dispersed encoded data slices from the set of re-dispersal storage units; and

decode, based on re-dispersal parameters, the set of re-dispersed encoded data slices to reproduce the re-dispersed existing encoded data slice.

14. The computing device of claim 9, wherein the processing module is further operable to:

when the approach includes the fostering new encoded data slices;

identify a foster storage unit; and

instruct the computing device to send the new encoded data slices to the foster storage unit.

15. The computing device of claim 9, wherein the processing module is further operable to:

when the approach includes the replicating the existing encoded data slices;

identify a replicating storage unit; and

instruct the identified storage unit to send a copy of at least some of the encoded data slices to the replicating storage unit.

16. The computing device of claim 9, wherein the processing module is further operable to:

when the approach includes the re-dispersing the existing encoded data slices;

determine re-dispersal parameters;

identify a set of re-dispersal storage units; and

instruct the identified storage unit to;

dispersed storage error encode, in accordance with the re-dispersal parameters, one of the encoded data slices to create sub-slices; and

send the sub-slices to the set of re-dispersal storage units.

17. A computer readable storage device comprises:

a first memory section for storing operational instructions that, when executed by a computing device, causes the computing device to;

identify a storage unit of a set of storage units within a dispersed storage system as being likely to fail;

a second memory section for storing operational instructions that, when executed by the computing device, causes the computing device to;

determine an approach for minimizing rebuilding of encoded data slices stored on the identified store unit in event of a failure of the identified storage unit, wherein the approach is at least one approach option from a list of approach options, wherein the list of approach options includes fostering new encoded data slices, replicating existing encoded data slices, and re-dispersing existing encoded data slices; and

implement the approach regarding the identified storage unit; and

a third memory section for storing operational instructions that, when executed by the computing device, causes the computing device to;

when the identified storage unit fails, retrieve, via the interface, the encoded data slices that were stored on the identified store unit based on the approach.

18. The computer readable storage device of claim 17, wherein the first memory section further stores operational instructions that, when executed by the computing device, causes the computing device to identify the storage unit by:

determining a detection of at least one of;

a maintenance cycle;

a network failure;

an error message;

a power indicator;

a weather indicator;

an earthquake indicator; and

an estimated future availability indicator.

19. The computer readable storage device of claim 17, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to retrieve the encoded data slices by:

when the approach includes the fostering new encoded data slices;

sending a retrieval command to a foster storage unit that is storing the new encoded data slices; and

receiving the fostered encoded data slices.

20. The computer readable storage device of claim 17, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to retrieve the encoded data slices by:

when the approach includes the replicating existing encoded data slices;

sending a retrieval command to a replication storage unit that is storing at least one of the replicated existing encoded data slices; and

receiving the at least one of the replicated existing encoded data slices.

21. The computer readable storage device of claim 17, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to retrieve the encoded data slices by:

when the approach includes the re-dispersed existing encoded data slices;

sending a retrieval command to a set of re-dispersal storage units regarding a re-dispersed existing encoded data slice of the re-dispersed existing encoded data slices;

receiving a set of re-dispersed encoded data slices from the set of re-dispersal storage units; and

decoding, based on re-dispersal parameters, the set of re-dispersed encoded data slices to reproduce the re-dispersed existing encoded data slice.

22. The computer readable storage device of claim 17 wherein the second memory section stores further operational instructions that, when executed by the computing device, causes the computing device to:

when the approach includes the fostering new encoded data slices;

identify a foster storage unit; and

instruct the computing device to send the new encoded data slices to the foster storage unit.

23. The computer readable storage device of claim 17 wherein the second memory section stores further operational instructions that, when executed by the computing device, causes the computing device to:

when the approach includes the replicating the existing encoded data slices;

identify a replicating storage unit; and

instruct the identified storage unit to send a copy of at least some of the encoded data slices to the replicating storage unit.

24. The computer readable storage device of claim 17 wherein the second memory section stores further operational instructions that, when executed by the computing device, causes the computing device to:

when the approach includes the re-dispersing the existing encoded data slices;

determine re-dispersal parameters;

identify a set of re-dispersal storage units; and

instruct the identified storage unit to;

dispersed storage error encode, in accordance with the re-dispersal parameters, one of the encoded data slices to create sub-slices; and

send the sub-slices to the set of re-dispersal storage units.