Fault resilient storage device

Patent metadata

Field	Value
Publication number	US-11803446-B2
Application number	US-202017109053-A
Country	US
Kind code	B2
Filing date	Dec 1, 2020
Priority date	Jul 13, 2020
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

A storage device, and a method for operating a storage device. In some embodiments, the storage device includes storage media, and the method includes: determining, by the storage device, that the storage device is in a first fault state from which recovery is possible by power cycling the storage device or by formatting the storage media; determining, by the storage device, that the storage device is in a second fault state from which partial recovery is possible by operating the storage device with reduced performance, with reduced capacity, or in a read-only mode; and operating the storage device with reduced performance, with reduced capacity, or in the read-only mode.

First claim

What is claimed is:

1. A method for operating a storage device comprising storage media, the method comprising:
determining, by the storage device, that the storage device is in a first fault state from which recovery is possible by power cycling the storage device or by formatting the storage media;
determining, by the storage device, that the storage device is in a second fault state from which partial recovery is possible by operating the storage device with reduced performance, with reduced capacity, or in a read-only mode; and
operating the storage device with reduced performance, with reduced capacity, or in the read-only mode.

2. The method of claim 1 , further comprising:
determining, by the storage device, that the storage device is in a third fault state different from the first fault state and the second fault state; and
operating the storage device in a mode in which read and write operations are not performed, and in which the storage device returns errors in response to received read or write commands, wherein:
the storage device comprises a controller comprising a first core and a second core, and
the third fault state comprises a sub-state in which the first core determines that the second core has failed.

3. The method of claim 1 , further comprising:
receiving a query, from a host, regarding a status of the storage device, and
responding to the query with a status corresponding to a status in a status hierarchy.

4. The method of claim 3 , wherein the status hierarchy comprises a first level, comprising:
a fully resilient status, corresponding to the first fault state; and
a partially resilient status, corresponding to the second fault state.

5. The method of claim 4 , wherein the partially resilient status comprises a first sub-status indicating a loss of capability, the first sub-status comprising:
a first sub-sub-status, indicating operation in a sustainable read-only mode; and
a second sub-sub-status, indicating operation in an unsustainable read-only mode.

6. The method of claim 3 wherein the receiving of the query comprises receiving the query through a nonvolatile memory express (NVMe) interface, and the responding to the query comprises responding through the nonvolatile memory express (NVMe) interface.

7. The method of claim 1 , wherein:
the first fault state comprises a first sub-state in which a program execution error of a controller of the storage device has caused incorrect data to be written to the storage media;
the determining that the storage device is in the first fault state comprises determining that a pointer is out of range; and
the first fault state comprises a second sub-state in which a program execution error of a controller of the storage device has occurred since the most recent write to storage media by the controller.

8. The method of claim 7 , further comprising reformatting a portion of the storage media, wherein the reformatting comprises reformatting the entire storage media.

9. The method of claim 1 , comprising operating the storage device with reduced performance.

10. The method of claim 9 , wherein the operating with reduced performance comprises:
receiving, from a host connected to the storage device, a write command comprising data;
writing the data to the storage media; and
sending a command completion to the host,
wherein the writing of the data to the storage media and the sending of the command completion to the host is performed as part of a synchronous write.

11. The method of claim 9 , wherein the operating with reduced performance comprises:
performing a first write to the storage media;
waiting, during an interval corresponding to the reduced performance; and
performing a second write to the storage media.

12. The method of claim 1 , comprising operating the storage device with reduced capacity.

13. A storage device comprising:
a processing circuit; and
storage media,
the processing circuit being configured to:
determine that the storage device is in a first fault state from which recovery is possible by power cycling the storage device or by formatting the storage media;
determine that the storage device is in a second fault state from which partial recovery is possible by operating the storage device with reduced performance, with reduced capacity, or in a read-only mode; and
operate the storage device with reduced performance, with reduced capacity, or in the read-only mode.

14. The storage device of claim 13 , wherein the processing circuit is further configured to:
receive a query, from a host, regarding a status of the device, and
respond to the query with a status corresponding to a status in a status hierarchy,
wherein the status hierarchy comprises a first level, comprising:
a fully resilient status, corresponding to the first fault state; and
a partially resilient status, corresponding to the second fault state.

15. The storage device of claim 14 wherein the receiving of the query comprises receiving the query through a nonvolatile memory express (NVMe) interface, and the responding to the query comprises responding through the nonvolatile memory express (NVMe) interface.

16. The storage device of claim 13 , wherein the processing circuit is configured to operate the storage device with reduced performance,
wherein the operating with reduced performance comprises:
performing a first write to the storage media;
waiting, during an interval corresponding to the reduced performance; and
performing a second write to the storage media.

17. A system, comprising a storage device comprising:
means for processing; and
storage media,
the means for processing being configured to:
determine that the storage device is in a first fault state from which recovery is possible by power cycling the storage device or by formatting the storage media;
determine that the storage device is in a second fault state from which partial recovery is possible by operating the storage device with reduced performance, with reduced capacity, or in a read-only mode; and
operate the storage device with reduced performance, with reduced capacity, or in the read-only mode.

18. The system of claim 17 , wherein the means for processing is further configured to:
receive a query, from a host, regarding a status of the device, and
respond to the query with a status corresponding to a status in a status hierarchy,
wherein the status hierarchy comprises a first level, comprising:
a fully resilient status, corresponding to the first fault state; and
a partially resilient status, corresponding to the second fault state.

19. The system of claim 18 wherein the receiving of the query comprises receiving the query through a nonvolatile memory express (NVMe) interface, and the responding to the query comprises responding through the nonvolatile memory express (NVMe) interface.

20. The system of claim 17 , wherein the means for processing is configured to operate the storage device with reduced performance,
wherein the operating with reduced performance comprises:
receiving, from a host connected to the storage device, a write command comprising data;
writing the data to the storage media; and
sending a command completion to the host,
wherein the writing of the data to the storage media and the sending of the command completion to the host is performed as part of a synchronous write.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Ki Yang Seok
• Ryu Sungwook
• Kim Seontaek
• Choi Changho
• Najafabadi Ehsan

Classifications

• G06F11/1428 Primary

  with loss of hardware functionality · CPC title

• G06F3/065

  Replication mechanisms · CPC title

• G06F3/0619

  in relation to data integrity, e.g. data losses, bit errors · CPC title

• G06F3/0634 Primary

  by changing the state or mode of one or more devices · CPC title

• G06F3/0644

  Management of space entities, e.g. partitions, extents, pools · CPC title