Triggering a Process to Reduce Declared Capacity of a Storage Device in a Multi-Storage-Device Storage System

• US 20160062665A1
• Filed: 02/12/2015
• Published: 03/03/2016
• Est. Priority Date: 09/02/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Samuels, Allen, Kruger, Warren Fritz, Truong, Linh Tien
• Granted Patent: US 9,582,193 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 2212/7204 Capacity control, e.g. partitioning, end-of-life degradation
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 2212/7211 Wear leveling
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0629 Configuration or reconfiguration of storage systems
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 16/00 Erasable programmable read-only memories G11C14/00 takes precedence

Abstract

Systems, methods and/or devices are used to enable triggering a process to reduce declared capacity of a storage device in a multi-storage-device storage system. In one aspect, the method includes: (1) obtaining, for each storage device of a plurality of storage devices of the storage system, one or more metrics of the storage device, the storage device including non-volatile memory, (2) detecting a trigger condition for reducing declared capacity of the non-volatile memory of a respective storage device of the plurality of storage devices, the trigger condition detected in accordance with the one or more metrics of one or more storage devices, and (3) enabling an amelioration process associated with the detected trigger condition, the amelioration process to reduce declared capacity of the non-volatile memory of the respective storage device. In some embodiments, the respective storage device includes one or more flash memory devices.

Claims

1. A method of managing a storage system, the method comprising:

obtaining, for each storage device of a plurality of storage devices of the storage system, one or more metrics of the storage device, the storage device including non-volatile memory;

detecting a trigger condition for reducing declared capacity of the non-volatile memory of a respective storage device of the plurality of storage devices of the storage system, the trigger condition detected in accordance with the one or more metrics of one or more storage devices of the plurality of storage devices; and

enabling an amelioration process associated with the detected trigger condition, the amelioration process to reduce declared capacity of the non-volatile memory of the respective storage device.

2. The method of claim 1, further comprising:

prior to detecting the trigger condition, detecting a first wear condition of the non-volatile memory of the respective storage device, wherein a total storage capacity of the non-volatile memory of the respective storage device includes declared capacity and over-provisioning; and

in response to detecting the first wear condition, performing a remedial action that reduces over-provisioning of the non-volatile memory of the respective storage device without reducing declared capacity of the non-volatile memory of the respective storage device.

3. The method of claim 2, wherein detecting the trigger condition comprises detecting a second wear condition distinct from the first wear condition.

4. The method of claim 1, wherein enabling the amelioration process associated with the detected trigger condition includes notifying a host to which the respective storage device is operatively coupled of the trigger condition.

5. The method of claim 1, wherein enabling the amelioration process associated with the detected trigger condition includes:

receiving a query from a host to which the respective storage device is operatively coupled; and

in response to receiving the query, reporting the trigger condition.

6. The method of claim 1, wherein enabling the amelioration process associated with the detected trigger condition includes:

receiving a command from a host to which the respective storage device is operatively coupled; and

in response to receiving the command, sending a response to the command and a notification of the trigger condition.

7. The method of claim 1, wherein enabling the amelioration process associated with the detected trigger condition includes:

receiving a command from a host to which the respective storage device is operatively coupled; and

in response to receiving the command, sending a response to the command and a notification that prompts the host to obtain information with respect to the trigger condition.

8. The method of claim 4, wherein the host includes a client on behalf of which data is stored in the storage system.

9. The method of claim 4, wherein the host includes a storage system controller of the storage system.

10. The method of claim 4, wherein the host includes a cluster controller of the storage system.

11. The method of claim 1, wherein enabling the amelioration process associated with the detected trigger condition includes scheduling the amelioration process to be performed on the respective storage device.

12. The method of claim 1, wherein enabling the amelioration process associated with the detected trigger condition includes determining one or more parameters for the amelioration process.

13. The method of claim 12, wherein enabling the amelioration process associated with the detected trigger condition further includes reporting at least a subset of the one or more parameters for the amelioration process.

14. The method of claim 1, wherein obtaining one or more metrics of the respective storage device includes obtaining at least one metric, of the one or more metrics, for each memory portion of a plurality of memory portions of the respective storage device.

15. The method of claim 1, wherein the one or more metrics of the respective storage device include one or more status metrics corresponding to the respective storage device'"'"'s ability to retain data.

16. The method of claim 1, wherein the one or more metrics of the respective storage device include one or more performance metrics corresponding to performance of the respective storage device.

17. The method of claim 1, wherein the one or more metrics of the respective storage device include one or more wear metrics corresponding to wear on the respective storage device.

18. The method of claim 1, wherein the one or more metrics of the respective storage device include one or more time metrics.

19. The method of claim 1, wherein the one or more metrics of the respective storage device include values of the one or more metrics from more than one time.

20. The method of claim 1, further comprising:

after enabling the amelioration process;

re-evaluating the trigger condition in accordance with the one or more metrics of the one or more storage devices of the plurality of storage devices; and

in accordance with a determination that the trigger condition is no longer valid, aborting the amelioration process to reduce declared capacity of the non-volatile memory of the respective storage device.

21. The method of claim 1, wherein the obtaining, the enabling, or both the obtaining and the enabling are performed by one or more subsystems of the storage system distinct from the plurality of storage devices.

22. The method of claim 1, wherein the respective storage device comprises one or more flash memory devices.

23. A storage system, comprising:

non-volatile memory;

one or more processors; and

controller memory storing one or more programs, which when executed by the one or more processors cause the storage system to perform operations comprising;

obtaining, for each storage device of a plurality of storage devices of the storage system, one or more metrics of the storage device, the storage device including non-volatile memory;

detecting a trigger condition for reducing declared capacity of the non-volatile memory of a respective storage device of the plurality of storage devices of the storage system, the trigger condition detected in accordance with the one or more metrics of one or more storage devices of the plurality of storage devices; and

enabling an amelioration process associated with the detected trigger condition, the amelioration process to reduce declared capacity of the non-volatile memory of the respective storage device.

24. The storage system of claim 23, wherein the one or more programs further include instructions that, when executed by the one or more processors, cause the storage system to perform operations comprising:

prior to detecting the trigger condition, detecting a first wear condition of the non-volatile memory of the respective storage device, wherein a total storage capacity of the non-volatile memory of the respective storage device includes declared capacity and over-provisioning; and

in response to detecting the first wear condition, performing a remedial action that reduces over-provisioning of the non-volatile memory of the respective storage device without reducing declared capacity of the non-volatile memory of the respective storage device.

25. A non-transitory computer readable storage medium, storing one or more programs configured for execution by one or more processors of a storage system, the one or more programs including instructions for:

obtaining, for each storage device of a plurality of storage devices of the storage system, one or more metrics of the storage device, the storage device including non-volatile memory;

detecting a trigger condition for reducing declared capacity of the non-volatile memory of a respective storage device of the plurality of storage devices of the storage system, the trigger condition detected in accordance with the one or more metrics of one or more storage devices of the plurality of storage devices; and

enabling an amelioration process associated with the detected trigger condition, the amelioration process to reduce declared capacity of the non-volatile memory of the respective storage device.

26. The non-transitory computer readable storage medium of claim 25, wherein the one or more programs further include instructions for:

prior to detecting the trigger condition, detecting a first wear condition of the non-volatile memory of the respective storage device, wherein a total storage capacity of the non-volatile memory of the respective storage device includes declared capacity and over-provisioning; and

in response to detecting the first wear condition, performing a remedial action that reduces over-provisioning of the non-volatile memory of the respective storage device without reducing declared capacity of the non-volatile memory of the respective storage device.