Transferring encoded data slices in a dispersed storage network

• US 10,402,122 B2
• Filed: 03/28/2016
• Issued: 09/03/2019
• Est. Priority Date: 05/29/2015
• Status: Expired due to Fees

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Resch, Jason K., Motwani, Manish
• Primary Examiner(s): Fleurantin, Jean B
• Application Number:
  US15/082,887
• Publication Number:
  US 20160350329A1
• Time in Patent Office: 1,254 Days
• Field of Search: 707827, 714 622
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0622 in relation to access
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A method for transferring encoded data slices from a first storage unit to a second storage unit begins by a processing module ascertaining a first mathematical process used to determine that the encoded data slices are to be stored in the first storage unit, where the first mathematical process includes a first mathematical function sequence and a first set of coefficients. The method continues with the processing module determining a second mathematical process, which indicates that the encoded data slices are to be stored in the second storage unit, where the second mathematical process corresponds to an adjustment of at least one of the first mathematical function sequence and the first set of coefficients. The method continues with the processing module transferring, based on a transfer command, the encoded data slices from the first storage unit to the second storage unit utilizing the second mathematical process.

Claims

1. A method for transferring encoded data slices from a first storage unit of a dispersed storage network (DSN) to a second storage unit of the DSN, the method comprises:

ascertaining a first mathematical process used to determine that the encoded data slices are to be stored in the first storage unit, wherein the first mathematical process includes a first mathematical function sequence and a first set of coefficients, wherein the first set of coefficients includes a plurality of identifying coefficients and a plurality of weighting coefficients, and wherein the first mathematical function sequence includes a plurality of mathematical functions and a score analysis function, wherein a first mathematical function of the plurality of mathematical functions includes a deterministic function, a normalizing function, and a scoring function, wherein the first mathematical function operates on a slice name of one of the encoded data slices, one of the plurality of identifying coefficients that corresponds to the first storage unit, and one of the plurality of weighting coefficients that corresponds to the first storage unit, to produce a first score, wherein the score analysis function selects one of the scores to produce a selected score, and wherein, when the selected score is the first score, the first mathematical process identifies the first storage unit;

determining a second mathematical process, which indicates that the encoded data slices are to be stored in the second storage unit, wherein the second mathematical process corresponds to an adjustment of at least one of;

the first mathematical function sequence and the first set of coefficients; and

transferring, based on a transfer command, the encoded data slices from the first storage unit to the second storage unit utilizing the second mathematical process.

2. The method of claim 1 further comprises:

maintaining, for the encoded data slices, a record of the first and second mathematical processes until transferring of the encoded data slices from the first storage unit to the second storage unit is complete.

3. The method of claim 1, wherein the determining the second mathematical process comprises:

setting an identifying coefficient associated with the second storage unit to a same value as the one of the plurality of identifying coefficients that corresponds to the first storage unit;

setting a weighting coefficient associated with the second storage unit to the same value as the one of the plurality of weighting coefficients that corresponds to the first storage unit; and

setting the one of the plurality of weighting coefficients that corresponds to the first storage unit to zero.

4. The method of claim 1, wherein the determining the second mathematical process comprises:

setting a weighting coefficient associated with the second storage unit to a same value as the one of the plurality of weighting coefficients that corresponds to the first storage unit;

setting the one of the plurality of weighting coefficients that corresponds to the first storage unit to zero; and

establishing a deterministic function of a second mathematical function of the second mathematical process to produce an identical result as the deterministic function of the first mathematical function.

5. The method of claim 1 further comprises:

ascertaining the first mathematical process used to determine that the encoded data slices are to be stored in a first set of storage units of the DSN, wherein the first set of storage units includes the first storage unit;

determining the second mathematical process, which indicates that the encoded data slices are to be stored in a second set of storage units of the DSN, wherein the second set of storage units includes the second storage unit; and

transferring, based on the transfer command, the encoded data slices from the first set of storage units to the second set of storage units utilizing the second mathematical process.

6. A method for storing encoded data slices in storage units of a dispersed storage network (DSN), the method comprises:

determining, by a computing device of the DSN, a slice level of association of the encoded data slices for storing the encoded data slices in the storage units;

determining, by the computing device, a mathematical process that identifies a set of the encoded data slices for storage in one or more storage units of the storage units, wherein the mathematical process includes a mathematical function sequence and a set of coefficients, wherein the set of coefficients includes a plurality of identifying coefficients and a plurality of weighting coefficients, wherein the mathematical function sequence includes a plurality of mathematical functions and a score analysis function, wherein a first mathematical function of the plurality of mathematical functions includes a deterministic function, a normalizing function, and a scoring function, wherein the first mathematical function operates on a slice name of one of the encoded data slices, one of the plurality of identifying coefficients that corresponds to the one or more storage units, and one of the plurality of weighting coefficients to produce a first score, wherein the score analysis function selects one of the scores to produce a selected score, and wherein, when the selected score is the first score, the mathematical process identifies the one or more storage units; and

storing, by the computing device and based on a set of write commands, the set of encoded data slices by the one or more storage units in accordance with the mathematical process.

7. The method of claim 6, wherein the slice level comprises one of:

an individual slice level;

a data segment level;

a data object level;

a slice index level; and

a vault level.

8. The method of claim 6 further comprises:

determining a data object level of association of the encoded data slices for storing the encoded data slices in a set of the storage units, wherein a data object is divided into a plurality of data segments, wherein a data segment is dispersed storage error encoded to produce the set of encoded data slices, and wherein dispersed storage error encoding of the data object yields the encoded data slices, wherein each of the encoded data slices has an associated slice name that includes a common data object identifier;

determining the mathematical process that, based on the common data object identifier, identifies the encoded data slices for storage in the set of storage units; and

storing, based on a plurality of sets of write commands, the encoded data slices by the set of storage units in accordance with the mathematical process.

9. A non-transitory computer readable storage medium comprises:

at least one memory section that stores operational instructions that, when executed by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), causes the one or more computing devices to;

ascertain a first mathematical process used to determine that encoded data slices are to be stored in a first storage unit of the DSN, wherein the first mathematical process includes a first mathematical function sequence and a first set of coefficients, wherein the first set of coefficients including a plurality of identifying coefficients and a plurality of weighting coefficients, wherein the first mathematical function sequence includes a plurality of mathematical functions and a score analysis function, wherein a first mathematical function of the plurality of mathematical functions includes a deterministic function, a normalizing function, and a scoring function, wherein the first mathematical function operates on a slice name of one of the encoded data slices, one of the plurality of identifying coefficients that corresponds to the first storage unit, and one of the plurality of weighting coefficients that corresponds to the first storage unit, to produce a first score, wherein the score analysis function selects one of the scores to produce a selected score, and wherein, when the selected score is the first score, the first mathematical process identifies the first storage unit;

determine a second mathematical process, which indicates that the encoded data slices are to be stored in a second storage unit of the DSN, wherein the second mathematical process corresponds to an adjustment of at least one of;

the first mathematical function sequence and the first set of coefficients; and

transfer, based on a transfer command, the encoded data slices from the first storage unit to the second storage unit utilizing the second mathematical process.

10. The non-transitory computer readable storage medium of claim 9 further comprises:

the at least one memory section stores further operational instructions that, when executed by the one or more processing modules, causes the one or more computing devices of the DSN to;

maintain, for the encoded data slices, a record of the first and second mathematical processes until transferring of the encoded data slices from the first storage unit to the second storage unit is complete.

11. The non-transitory computer readable storage medium of claim 9, wherein the one or more processing modules functions to execute the operational instructions stored by the at least one memory section to cause the one or more computing devices of the DSN to determine the second mathematical process by:

setting an identifying coefficient associated with the second storage unit to a same value as the one of the plurality of identifying coefficients that corresponds to the first storage unit;

setting a weighting coefficient associated with the second storage unit to the same value as the one of the plurality of weighting coefficients that corresponds to the first storage unit; and

setting the one of the plurality of weighting coefficients that corresponds to the first storage unit to zero.

12. The non-transitory computer readable storage medium of claim 9, wherein the one or more processing modules functions to execute the operational instructions stored by the at least one memory section to cause the one or more computing devices of the DSN to determine the second mathematical process by:

setting a weighting coefficient associated with the second storage unit to a same value as the one of the plurality of weighting coefficients that corresponds to the first storage unit;

setting the one of the plurality of weighting coefficients that corresponds to the first storage unit to zero; and

establishing a deterministic function of a second mathematical function of the second mathematical process to produce an identical result as the deterministic function of the first mathematical function.

13. The non-transitory computer readable storage medium of claim 9 further comprises:

the at least one memory section stores further operational instructions that, when executed by the one or more processing modules, causes the one or more computing devices of the DSN to;

ascertain the first mathematical process used to determine that the encoded data slices are to be stored in a first set of storage units of the DSN, wherein the first set of storage units includes the first storage unit;

determine the second mathematical process, which indicates that the encoded data slices are to be stored in a second set of storage units of the DSN, wherein the second set of storage units includes the second storage unit; and

transfer, based on the transfer command, the encoded data slices from the first set of storage units to the second set of storage units utilizing the second mathematical process.

14. A non-transitory computer readable storage medium comprises:

at least one memory section that stores operational instructions that, when executed by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), causes the one or more computing devices to;

determine a slice level of association of encoded data slices for storing the encoded data slices in storage units of a dispersed storage network (DSN);

determine a mathematical process that identifies a set of the encoded data slices for storage in one or more storage units of the storage units, wherein the mathematical process includes a mathematical function sequence and a set of coefficients, wherein the set of coefficients includes a plurality of identifying coefficients and a plurality of weighting coefficients, wherein the mathematical function sequence includes a plurality of mathematical functions and a score analysis function, wherein a first mathematical function of the plurality of mathematical functions includes a deterministic function, a normalizing function, and a scoring function, wherein the first mathematical function operates on a slice name of one of the encoded data slices, one of the plurality of identifying coefficients that corresponds to the one or more storage units, and one of the plurality of weighting coefficients to produce a first score, wherein the score analysis function selects one of the scores to produce a selected score, and wherein, when the selected score is the first score, the mathematical process identifies the one or more storage units; and

store, based on a set of write commands, the set of encoded data slices by the one or more storage units in accordance with the mathematical process.

15. The non-transitory computer readable storage medium of claim 14, wherein the slice level comprises one of:

an individual slice level;

a data segment level;

a data object level;

a slice index level; and

a vault level.

16. The non-transitory computer readable storage medium of claim 14 further comprises:

the at least one memory section stores further operational instructions that, when executed by the one or more processing modules, causes the one or more computing devices of the DSN to;

determine a data object level of association of the encoded data slices for storing the encoded data slices in a set of the storage units, wherein a data object is divided into a plurality of data segments, wherein a data segment is dispersed storage error encoded to produce the set of encoded data slices, and wherein dispersed storage error encoding of the data object yields the encoded data slices, wherein each of the encoded data slices has an associated slice name that includes a common data object identifier;

determine the mathematical process that, based on the common data object identifier, identifies the encoded data slices for storage in the set of storage units; and

store, based on a plurality of sets of write commands, the encoded data slices by the set of storage units in accordance with the mathematical process.