Storage control system with data management mechanism and method of operation thereof

• US 9,183,137 B2
• Filed: 02/27/2013
• Issued: 11/10/2015
• Est. Priority Date: 02/27/2013
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Smart Storage Systems Incorporated (Western Digital Corporation)
• Inventors: Schmier, Jacob, Dancho, Mark, Higgins, James M, Jones, Ryan, Ellis, Robert W
• Primary Examiner(s): Rutz, Jared
• Assistant Examiner(s): EDOUARD, JEAN C
• Application Number:
  US13/779,352
• Publication Number:
  US 20140244899A1
• Time in Patent Office: 986 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays

Abstract

A method of operation of a storage control system includes: calculating a throttle threshold; identifying a detection point based on the throttle threshold; and calculating a number of write/erase cycles based on the detection point and the throttle threshold for writing a memory device.

Claims

1. A method of operation of a storage control system for a storage device comprising:

identifying a detection point at a point in time in accordance with a determination that the number of write/erase cycles for the storage device satisfies a time-varying throttle threshold;

calculating a projected number of write/erase cycles corresponding to the detection point; and

after identifying the detection point, limiting write operations for the storage device in accordance with the projected number of write/erase cycles.

2. The method as claimed in claim 1 including determining a current value, at the point in time, of the time-varying threshold based on a threshold offset.

3. The method as claimed in claim 1 wherein calculating the projected number of the write/erase cycles includes calculating the projected number of the write/erase cycles based on a threshold line having a half-remaining life point.

4. The method as claimed in claim 1 including accumulating access credits for accessing the storage device during periods in which write operations to the storage device do not occur, decreasing the access credits for accessing the storage device in accordance with write operations to the storage device, and enabling bursts of write operations to the storage device when the access credits for accessing the storage device are greater than zero.

5. The method as claimed in claim 1 further comprising periodically determining whether the number of write/erase cycles for the storage device satisfies a current value of the time-varying throttle threshold.

6. The method as claimed in claim 1 wherein the time-varying throttle threshold is determined based on a threshold line having a threshold offset and a target life point.

7. A storage control system comprising:

a storage device;

a memory controller; and

controller memory coupled to the memory controller, the controller memory including software that, when executed by the memory controller, cause the memory controller to;

identify a detection point at a point in time in accordance with a determination that the number of write/erase cycles for the storage device satisfies a time-varying throttle threshold;

calculate a projected number of write/erase cycles corresponding to the detection point; and

after identifying the detection point, limit write operations for the storage device in accordance with the projected number of write/erase cycles.

8. The system as claimed in claim 7 wherein the controller memory further includes software that, when executed by the memory controller, causes the memory controller to determine a current value, at the point in time, of the time-varying threshold based on a threshold offset.

9. The system as claimed in claim 7 wherein the controller memory further includes software that, when executed by the memory controller, causes the memory controller to calculate the projected number of the write/erase cycles based on a threshold line having a half-remaining life point.

10. The system as claimed in claim 7 wherein the controller memory further includes software that, when executed by the memory controller, causes the memory controller to accumulate access credits for accessing the storage device during periods in which write operations to the storage device do not occur, decrease the access credits for accessing the storage device in accordance with write operations to the storage device, and enable bursts of write operations to the storage device when the access credits for accessing the storage device are greater than zero.

11. The system as claimed in claim 7 wherein the controller memory further includes software that, when executed by the memory controller, causes the memory controller to determine an active device number for enabling a number of storage devices for throttling write operations when the detection point is identified, wherein the active device number is less than a total number of the storage devices.

12. The system as claimed in claim 7 wherein the controller memory further includes software that, when executed by the memory controller, causes the memory controller to calculate the number of the write/erase cycles based on an update interval.

13. The system as claimed in claim 7 wherein the controller memory further includes software that, when executed by the memory controller, causes the memory controller to determine the time-varying throttle threshold based on a threshold line having a threshold offset and a target life point.

14. The system as claimed in claim 7 wherein controller memory further includes software that, when executed by the memory controller, causes the memory controller to:

convert the number of the write/erase cycles into an equivalent number of write operations; and

accumulate access credits for accessing the storage device during periods in which write operations to the storage device do not occur, decrease the access credits for accessing the storage device in accordance with write operations to the storage device, and enable bursts of write operations to the storage device when the access credits for accessing the storage device are greater than zero.

15. A non-volatile storage device, comprising:

non-volatile memory; and

a memory controller that includes

one or more processors, and

controller memory storing one or more programs that when executed by the one or more processors cause the non-volatile storage device to perform operations including;

identifying a detection point at a point in time in accordance with a determination that the number of write/erase cycles for the storage device satisfies a time-varying throttle threshold;

calculating a projected number of write/erase cycles corresponding to the detection point; and

after identifying the detection point, limiting write operations for the storage device in accordance with the projected number of write/erase cycles.

16. The non-volatile storage device of claim 15, wherein the memory controller includes:

a threshold comparison module, coupled to a threshold calculation module, for identifying the detection point; and

an operation update module, coupled to the threshold comparison module, for calculating a projected number of write/erase cycles corresponding to the detection point;

a device control module, coupled to the operation update module, for, after identifying the detection point, limiting write operations for the storage device in accordance with the projected number of write/erase cycles.

17. The non-volatile storage device of claim 16, wherein the threshold calculation module is for determining a current value, at the point in time, of the time-varying threshold based on a threshold offset.

18. The non-volatile storage device of claim 16, wherein the operation update module is for calculating the projected number of the write/erase cycles based on a threshold line having a half-remaining life point.

19. The non-volatile storage device of claim 16, wherein:

the operation update module is for converting the number of the write/erase cycles into an equivalent number of write operations; and

the device control module is for accumulating access credits for accessing the storage device during periods in which write operations to the storage device do not occur, decreasing the access credits for accessing the storage device in accordance with write operations to the storage device, and enabling bursts of write operations to the storage device when the access credits for accessing the storage device are greater than zero.