Notification of trigger condition to reduce declared capacity of a storage device

• US 9,582,212 B2
• Filed: 02/12/2015
• Issued: 02/28/2017
• Est. Priority Date: 09/02/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Samuels, Allen, Kruger, Warren Fritz, Truong, Linh Tien
• Primary Examiner(s): PATEL, KAUSHIKKUMAR M
• Application Number:
  US14/621,253
• Publication Number:
  US 20160062693A1
• Time in Patent Office: 747 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• 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 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0629 Configuration or reconfiguration of storage systems
• CPC Class Codes: G06F 3/0634 by changing the state or mode of one or more devices
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 11/5621 using charge storage in a floating gate
• CPC Class Codes: G11C 16/08 Address circuits; Decoders; Word-line control circuits
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles
• CPC Class Codes: G11C 2211/5641 Multilevel memory having cells with different number of storage levels

Abstract

Systems, methods and/or devices are used to enable notification of a trigger condition to reduce declared capacity of a storage device. In one aspect, the method includes, at a storage device of a storage system, the storage device including non-volatile memory: (1) detecting a trigger condition for reducing declared capacity of the non-volatile memory of the storage device, and (2) notifying a host to which the storage device is operatively coupled of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device, the trigger condition for enabling performance of an amelioration process to reduce declared capacity of the non-volatile memory of the storage device. In some embodiments, the storage device includes one or more flash memory devices.

Claims

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

at a storage device of the storage system, the storage device including non-volatile memory;

detecting a trigger condition for reducing declared capacity of the non-volatile memory of the storage device, wherein declared capacity is storage capacity available to a host and wherein a total storage capacity of the non-volatile memory of the storage device includes declared capacity and over-provisioning;

notifying the host to which the storage device is operatively coupled of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device, the trigger condition for enabling performance of an amelioration process to reduce declared capacity of the non-volatile memory of the storage device;

prior to detecting the trigger condition, detecting a first wear condition of the non-volatile memory of the storage device; and

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

wherein detecting the trigger condition comprises detecting a second wear condition distinct from the first wear condition.

2. The method of claim 1, wherein the host includes a client on behalf of which data is stored in the storage system.

3. The method of claim 1, wherein the host includes a storage system controller of the storage system.

4. The method of claim 1, wherein the host includes a cluster controller of the storage system.

5. The method of claim 1, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes notifying the host with an unsolicited communication.

6. The method of claim 1, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes:

receiving a query from the host; and

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

7. The method of claim 1, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes:

receiving a command from the host; and

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

8. The method of claim 1, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes:

receiving a command from the host; 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.

9. The method of claim 1, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device further includes notifying the host that the storage device is in read-only mode.

10. The method of claim 1, wherein the trigger condition is detected by the storage device in accordance with one or more metrics of the storage device.

11. The method of claim 10, further comprising:

after notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device;

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

in accordance with a determination that the trigger condition is no longer valid, notifying the host of an absence of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device.

12. The method of claim 1, wherein the amelioration process to reduce declared capacity of the non-volatile memory of the storage device includes a process to reduce utilization of the non-volatile memory of the storage device.

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

14. A storage device, 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 device to perform operations comprising;

detecting a trigger condition for reducing declared capacity of the non-volatile memory of the storage device, wherein declared capacity is storage capacity available to a host and wherein a total storage capacity of the non-volatile memory of the storage device includes declared capacity and over-provisioning;

notifying the host to which the storage device is operatively coupled of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device;

prior to detecting the trigger condition, detecting a first wear condition of the non-volatile memory of the storage device; and

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

wherein detecting the trigger condition comprises detecting a second wear condition distinct from the first wear condition.

15. The storage device of claim 14, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes notifying the host with an unsolicited communication.

16. The storage device of claim 14, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes:

receiving a query from the host; and

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

17. The storage device of claim 14, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes:

receiving a command from the host; and

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

18. The storage device of claim 14, wherein the storage device comprises one or more flash memory devices.

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

detecting a trigger condition for reducing declared capacity of the non-volatile memory of the storage device, wherein declared capacity is storage capacity available to a host and wherein a total storage capacity of the non-volatile memory of the storage device includes declared capacity and over-provisioning;

notifying the host to which the storage device is operatively coupled of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device, the trigger condition for enabling performance of an amelioration process to reduce declared capacity of the non-volatile memory of the storage device;

prior to detecting the trigger condition, detecting a first wear condition of the non-volatile memory of the storage device; and

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

wherein detecting the trigger condition comprises detecting a second wear condition distinct from the first wear condition.

20. The non-transitory computer readable storage medium of claim 19, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes notifying the host with an unsolicited communication.

21. The non-transitory computer readable storage medium of claim 19, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes:

receiving a query from the host; and

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

22. The non-transitory computer readable storage medium of claim 19, wherein notifying the host of the trigger condition for reducing declared capacity of the non-volatile memory of the storage device includes:

receiving a command from the host; and

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

23. The non-transitory computer readable storage medium of claim 19, wherein the storage device comprises one or more flash memory devices.