Migrating an encoded data slice based on an end-of-life memory level of a memory device

• US 10,157,002 B2
• Filed: 08/05/2011
• Issued: 12/18/2018
• Est. Priority Date: 08/26/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Grube, Gary W., Resch, Jason K., Markison, Timothy W., Volvovski, Ilya, Motwani, Manish
• Primary Examiner(s): Rutz, Jared I
• Assistant Examiner(s): Ayash, Marwan
• Application Number:
  US13/204,061
• Publication Number:
  US 20120054456A1
• Time in Patent Office: 2,692 Days
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 12/0223 User address space allocation, e.g. contiguous or non contiguous base addressing
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• 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 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

A method begins by a processing module determining a priority access level of an encoded data slice stored on a memory device. The method continues with the processing module determining an end-of-life memory level for the memory device. The method continues with the processing module determining whether to migrate the encoded data slice from the memory device based on the priority access level and the end-of-life memory level. The method continues with the processing module identifying another memory device. The method continues with the processing module facilitating migration of the encoded data slice to another memory device.

Claims

1. A method comprising:

determining a priority access level of an encoded data slice stored on a memory device;

determining a soft failure level for the memory device;

determining whether to migrate the encoded data slice from the memory device based on the priority access level and the soft failure level; and

when it is determined to migrate the encoded data slice from the memory device;

identifying another memory device; and

facilitating migration of the encoded data slice to the another memory device.

2. The method of claim 1, wherein the facilitating migration of the encoded data slice comprises:

determining to replicate the encoded data slice; and

storing the encoded data slice in the other memory device.

3. The method of claim 2, wherein the storing the encoded data slice in the other memory device comprises:

identifying the other memory device;

determining another soft failure level of the other memory device;

comparing a representation of the priority access level and the other soft failure level to a sliding migration scale; and

when the representation compares favorably to the sliding migration scale, facilitate storing the encoded data slice in the other memory device.

4. The method of claim 1 further comprises:

deleting the encoded data slice from the memory device; and

updating a memory assignment table to indicate that the other memory device is storing the encoded data slice.

5. The method of claim 1 further comprises:

tracking migration history of encoded data slices from the memory device; and

decommissioning the memory device based on the migration history.

6. The method of claim 1, wherein the determining the priority access level is based on at least one of:

a number of accesses of the encoded data slice;

a service-level agreement;

a data type indicator;

a predetermination;

a lookup;

a priority level of data contained within the encoded data slice;

a priority level of a user account associated with the encoded data slice;

a message;

or

a command.

7. The method of claim 1, wherein the determining the soft failure level is based on at least one:

a service life indicator;

a historical performance record;

an error message;

an error rate;

a performance test result;

a predetermination;

a query;

a message;

or

a command.

8. The method of claim 1, wherein the determining whether to migrate the encoded data slice comprises at least one of:

comparing a representation of the priority access level and the soft failure level to a sliding migration scale; and

when the representation compares unfavorably to the sliding migration scale, indicating the migration of the encoded data slice.

9. A distributed storage (DS) processing unit comprises:

an interface for coupling to a plurality of memory devices; and

a processing module operable to;

determine a priority access level of an encoded data slice stored on a memory device of the plurality of memory devices;

determine a soft failure level for the memory device;

determine whether to migrate the encoded data slice from the memory device based on the priority access level and the soft failure level; and

when it is determined to migrate the encoded data slice from the memory device;

identify another memory device of the plurality of memory devices; and

facilitate migrating the encoded data slice to the another memory device.

10. The DS processing unit of claim 9, wherein the processing module functions to facilitate migrating the encoded data slice by:

determining to replicate the encoded data slice; and

storing, via the interface, the encoded data slice in the other memory device.

11. The DS processing unit of claim 10, wherein the processing module functions to store the encoded data slice in the other memory device by:

identifying the other memory device;

determining another soft failure level of the other memory device;

comparing a representation of the priority access level and the other soft failure level to a sliding migration scale; and

when the representation compares favorably to the sliding migration scale, facilitate storing, via the interface, the encoded data slice in the other memory device.

12. The DS processing unit of claim 9, wherein the processing module further functions to:

delete the encoded data slice from the memory device; and

update a memory assignment table to indicate that the other memory device is storing the encoded data slice.

13. The DS processing unit of claim 9, wherein the processing module further functions to:

track migration history of encoded data slices from the memory device; and

decommission the memory device based on the migration history.

14. The DS processing unit of claim 9, wherein the processing module functions to determine whether to migrate the encoded data slice by at least one of:

comparing a representation of the priority access level and the soft failure level to a sliding migration scale; and

when the representation compares unfavorably to the sliding migration scale, indicating the migration of the encoded data slice.

15. A memory system comprises:

a plurality of memory devices; and

a processing module operable to;

determine a priority access level of an encoded data slice stored on a memory device of the plurality of memory devices;

determine a soft failure level for the memory device;

determine whether to migrate the encoded data slice from the memory device based on the priority access level and the soft failure level; and

when it is determined to migrate the encoded data slice from the memory device;

identify another memory device of the plurality of memory devices; and

facilitate migrating the encoded data slice to the another memory device.

16. The memory system of claim 15, wherein the processing module functions to facilitate migrating the encoded data slice by:

determining to replicate the encoded data slice; and

storing the encoded data slice in the other memory device.

17. The memory system of claim 15, wherein the processing module functions to store the encoded data slice in the other memory device by:

identifying the other memory device;

determining another soft failure level of the other memory device;

comparing a representation of the priority access level and the other soft failure level to a sliding migration scale; and

when the representation compares favorably to the sliding migration scale, facilitate storing the encoded data slice in the other memory device.

18. The memory system of claim 15, wherein the processing module further functions to:

delete the encoded data slice from the memory device; and

update a memory assignment table to indicate that the other memory device is storing the encoded data slice.

19. The memory system of claim 15, wherein the processing module further functions to:

track migration history of encoded data slices from the memory device; and

decommission the memory device based on the migration history.

20. The memory system of claim 15, wherein the processing module functions to determine whether to migrate the encoded data slice by at least one of:

comparing a representation of the priority access level and the soft failure level to a sliding migration scale; and

when the representation compares unfavorably to the sliding migration scale, indicating the migration of the encoded data slice.