Rebuilding slices in a dispersed storage network

Patent metadata

Field	Value
Publication number	US-10248361-B2
Application number	US-201615334714-A
Country	US
Kind code	B2
Filing date	Oct 26, 2016
Priority date	Nov 30, 2015
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

A method for use in a dispersed storage network operates to select a recovery of selected ones of one or more first sets of encoded data slices in response to detecting a storage error associated with the selected ones of the one or more first sets of encoded data slices; issue requests for a second decode threshold number of encoded data slices of selected ones of one or more second sets of encoded data slices corresponding to the selected ones of the one or more first sets of encoded data slices; decode the second decode threshold number of encoded data slices to produce recovered data in response to receiving the second decode threshold number of encoded data slices; encode the recovered data utilizing first IDA parameters associated with the first IDA to produce one or more rebuilt encoded data slices corresponding to the selected ones of the one or more first sets of encoded data slices; and facilitate storage of the one or more rebuilt encoded data slices.

First claim

What is claimed is:

1. A method for execution by a processing system of a dispersed storage and task (DST) integrity processing unit that includes a processor, the method comprises:
selecting a recovery of selected ones of one or more first sets of encoded data slices in response to detecting a storage error associated with the selected ones of the one or more first sets of encoded data slices, wherein data is stored as the one or more first sets of encoded data slices in a plurality of dispersed storage and task execution (DSTE) units, the one or more first sets of encoded data slices encoded utilizing a first information dispersal algorithm (IDA) having a first decode threshold number, wherein the data is also stored as one or more second sets of encoded data slices in a subset of the plurality of DSTE units, the one or more second sets of encoded data slices encoded utilizing a second IDA having a second decode threshold number;
issuing requests for a second decode threshold number of encoded data slices of selected ones of the one or more second sets of encoded data slices corresponding to the selected ones of the one or more first sets of encoded data slices;
decoding the second decode threshold number of encoded data slices to produce recovered data in response to receiving the second decode threshold number of encoded data slices;
encoding the recovered data utilizing first IDA parameters associated with the first IDA to produce one or more rebuilt encoded data slices corresponding to the selected ones of the one or more first sets of encoded data slices; and
facilitating storage of the one or more rebuilt encoded data slices.

2. The method of claim 1 wherein selecting the recovery of the one or more first sets of encoded data slices includes identifying that the data is also stored as the one or more second sets of encoded data slices in the subset of the plurality of DSTE units.

3. The method of claim 1 wherein selecting the recovery of the one or more first sets of encoded data slices further includes identifying that the second decode threshold number is less than the first decode threshold number.

4. The method of claim 1 wherein issuing the requests for the second decode threshold number of encoded data slices includes identifying one or more of the subset of the plurality of DSTE units, generating read slice requests, and sending the read slice requests to the one or more of the subset of the plurality of DSTE units.

5. The method of claim 1 wherein decoding the second decode threshold number of encoded data slices includes identifying second IDA parameters for the second decode threshold number of encoded data slices, the IDA parameters corresponding to the second IDA, and dispersed storage error decoding the second decode threshold number of encoded data slices utilizing the second IDA parameters to produce the recovered data.

6. The method of claim 1 wherein encoding the recovered data includes identifying the first IDA parameters and utilizing the first IDA parameters to produce the rebuilt encoded data slice.

7. The method of claim 1 wherein facilitating the storage of the rebuilt encoded data slice includes identifying one or more of the plurality of DSTE units associated with the selected ones of the one or more first sets of encoded data slices and sending the rebuilt encoded data slice to the one or more of the plurality of DSTE units for storage.

8. A processing system of a first dispersed storage and task (DST) integrity processing 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:
select a recovery of selected ones of one or more first sets of encoded data slices in response to detecting a storage error associated with the selected ones of the one or more first sets of encoded data slices, wherein data is stored as the one or more first sets of encoded data slices in a plurality of dispersed storage and task execution (DSTE) units, the one or more first sets of encoded data slices encoded utilizing a first information dispersal algorithm (IDA) having a first decode threshold number, wherein the data is also stored as one or more second sets of encoded data slices in a subset of the plurality of DSTE units, the one or more second sets of encoded data slices encoded utilizing a second IDA having a second decode threshold number;
issue requests for a second decode threshold number of encoded data slices of selected ones of the one or more second sets of encoded data slices corresponding to the selected ones of the one or more first sets of encoded data slices;
decode the second decode threshold number of encoded data slices to produce recovered data in response to receiving the second decode threshold number of encoded data slices;
encode the recovered data utilizing first IDA parameters associated with the first IDA to produce one or more rebuilt encoded data slices corresponding to the selected ones of the one or more first sets of encoded data slices; and
facilitate storage of the one or more rebuilt encoded data slices.

9. The processing system of claim 8 wherein selecting the recovery of the one or more first sets of encoded data slices includes identifying that the data is also stored as the one or more second sets of encoded data slices in the subset of the plurality of DSTE units.

10. The processing system of claim 8 wherein selecting the recovery of the one or more first sets of encoded data slices further includes identifying that the second decode threshold number is less than the first decode threshold number.

11. The processing system of claim 8 wherein issuing the requests for the second decode threshold number of encoded data slices includes identifying one or more of the subset of the plurality of DSTE units, generating read slice requests, and sending the read slice requests to the one or more of the subset of the plurality of DSTE units.

12. The processing system of claim 8 wherein decoding the second decode threshold number of encoded data slices includes identifying second IDA parameters for the second decode threshold number of encoded data slices, the IDA parameters corresponding to the second IDA, and dispersed storage error decoding the second decode threshold number of encoded data slices utilizing the second IDA parameters to produce the recovered data.

13. The processing system of claim 8 wherein encoding the recovered data includes identifying the first IDA parameters and utilizing the first IDA parameters to produce the rebuilt encoded data slice.

14. The processing system of claim 8 wherein facilitating the storage of the rebuilt encoded data slice includes identifying one or more of the plurality of DSTE units associated with the selected ones of the one or more first sets of encoded data slices and sending the rebuilt encoded data slice to the one or more of the plurality of DSTE units for storage.

15. 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:
select a recovery of selected ones of one or more first sets of encoded data slices in response to detecting a storage error associated with the selected ones of the one or more first sets of encoded data slices, wherein data is stored as the one or more first sets of encoded data slices in a plurality of dispersed storage and task execution (DSTE) units, the one or m

Assignees

• IBM

Inventors

• Baptist Andrew D
• Dhuse Greg R
• Horan Scott M
• Khadiwala Ravi V
• Leggette Wesley B
• Motwani Manish
• Resch Jason K
• Viraraghavan Praveen
• Volvovski Ilya
• Vossberg Trevor J
• Wozniak Ethan S

Classifications

• H04L67/1097

  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 title

• G06F12/0891

  using clearing, invalidating or resetting means · CPC title

• G06F3/064

  Management of blocks · CPC title

• G06F11/1464

  for networked environments · CPC title

• G06F3/067 Primary

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title