Recovering unreadable data for a vaulted volume

• US 10,216,597 B2
• Filed: 04/29/2016
• Issued: 02/26/2019
• Est. Priority Date: 04/29/2016
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Jibbe, Mahmoud K., Holt, Keith
• Primary Examiner(s): Wilson, Yolanda L
• Application Number:
  US15/142,659
• Publication Number:
  US 20170315890A1
• Time in Patent Office: 1,033 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 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence

Abstract

A method, a computing device, and a non-transitory machine-readable medium for replacing an unreadable sector in a storage system is provided. In some embodiments, the method includes identifying a sector from a plurality of sectors in a physical memory of a storage device in a storage system as an unreadable sector. An unreadable sector is a sector that includes data that had been corrupted and cannot be recovered from data in the storage system. In some embodiments, the unreadable sector is recovered by receiving a copy of a sector identified as the unreadable sector from a cloud storage, where the copy of the sector stores readable data and the cloud storage is a separate storage from the storage system. The method then includes replacing the unreadable sector with the copy at the sector at a memory location in the physical memory occupied by the unreadable sector.

Claims

1. A method comprising:

identifying a sector from a plurality of sectors in a physical memory of a storage system as an unreadable sector;

determining that a logical block address range of the unreadable sector matches a logical block address range of a copy of the sector identified as the unreadable sector that was previously uploaded to a cloud storage, wherein the copy of the sector stores readable data and a match indicates that the logical block address of the unreadable sector has not changed since the copy of the sector was previously uploaded to the cloud storage;

based on the determining, receiving the copy of the sector from the cloud storage; and

replacing the unreadable sector with the copy of the sector at a same location in the physical memory occupied by the unreadable sector.

2. The method of claim 1, wherein the unreadable sector includes data that has been corrupted and cannot be recovered from data in the storage system that includes the storage device.

3. The method of claim 1, wherein the unreadable sector is a sector that cannot be recovered by the storage system that includes the storage device.

4. The method of claim 1, further comprising:

requesting the copy of the sector from the cloud storage using a memory address of the unreadable sector.

5. The method of claim 4, wherein the memory address comprises a logical block address.

6. The method of claim 1, further comprising:

requesting the copy of the sector identified as the unreadable sector in response to determining that the logical block address range of the unreadable sector matches the logical block address range of a copy of the sector.

7. The method of claim 1, further comprising:

identifying the sector as the unreadable sector as a result of a failure of the storage device.

8. The method of claim 1, wherein the sector identified as the unreadable sector cannot be recreated using a parity stored in the storage system.

9. The method of claim 1, further comprising:

generating a request that includes the logical block address range and an identifier of the copy of the sector identified as the unreadable sector.

10. A non-transitory machine readable medium having stored thereon instructions for performing a method comprising machine executable code, which when executed by at least one machine, cause the machine to:

identify a sector in a physical memory of a storage device in a storage system as an unreadable sector;

determine that a logical block address range of the unreadable sector matches a logical block address range of a copy of the sector identified as the unreadable sector that was previously uploaded to a cloud storage, wherein the copy of the sector stores readable data and a match indicates that the logical block address of the unreadable sector has not changed since the copy of the sector was previously uploaded to the cloud storage;

based on the determination, receive the copy of the sector from the cloud storage; and

replace the unreadable sector with the copy of the sector at a same location in the physical memory occupied by the unreadable sector.

11. The non-transitory machine readable medium of claim 10, wherein the unreadable sector includes data that has been corrupted and cannot be recovered from data in the storage system that includes the storage device.

12. The non-transitory machine readable medium of claim 10, wherein to identify the unreadable sector, the instructions for performing the method comprising machine executable code, which when executed by at least one machine, further causes the machine to:

identify the sector as the unreadable sector, in response to the storage system being unable to recover the sector from multiple computing devices communicatively connected to the storage system.

13. The non-transitory machine readable medium of claim 10, wherein the instructions for performing the method comprising machine executable code, which when executed by at least one machine, further causes the machine to:

request the copy of the sector from the cloud storage using a logical block address of the unreadable sector.

14. The non-transitory machine readable medium of claim 10, wherein the instructions for performing the method comprising machine executable code, which when executed by at least one machine, further causes the machine to:

request the copy of the sector identified as the unreadable sector in response to determining the match between the logical block address range of the unreadable sector and the logical block address range of a copy of the sector.

15. A computing device comprising:

a memory containing machine readable medium comprising machine executable code having stored thereon instructions for performing a method of memory management; and

a processor coupled to the memory, the processor configured to execute the machine executable code to cause the processor to;

identify a sector from a plurality of sectors in a physical memory of a storage device in a storage system as an unreadable sector;

determine that a logical block address range of the unreadable sector matches a logical block address range of a copy of the sector identified as the unreadable sector that was previously uploaded to a cloud storage, wherein the copy of the sector stores readable data and a match indicates that the logical block address of the unreadable sector has not changed since the copy of the sector was previously uploaded to the cloud storage;

receive the copy of the sector from the cloud storage; and

replace the unreadable sector with the copy of the sector at a same location in the physical memory occupied by the unreadable sector.

16. The computing device of claim 15, wherein the unreadable sector includes data that has been corrupted and cannot be recovered from data in the storage system that includes the storage device.

17. The computing device of claim 15, wherein the processor is further configured to execute the machine executable code to cause the processor to:

determine that the sector is the unreadable sector in response to the storage system that includes the storage device being unable to recover the sector.

18. The computing device of claim 15, wherein the processor is further configured to execute the machine executable code to cause the processor to:

request the copy of the sector from the cloud storage using a memory address of the unreadable sector.

19. The computing device of claim 15, wherein the processor is further configured to execute the machine executable code to cause the processor to:

request the copy of the sector identified as the unreadable sector in response to determining that the logical block address range of the unreadable sector matches a logical block address range of a copy of the sector.