Apparatus, system, and method to increase data integrity in a redundant storage system

• US 8,832,528 B2
• Filed: 05/18/2010
• Issued: 09/09/2014
• Est. Priority Date: 05/18/2009
• Status: Active Grant

• Current Assignee: Unification Technologies LLC (Acacia Research Corporation)
• Original Assignee: Fusion-IO Incorporated (Western Digital Corporation)
• Inventors: Thatcher, Jonathan, Flynn, David, Aune, Joshua, Fillingim, Jeremy, Inskeep, Bill, Strasser, John, Vigor, Kevin
• Primary Examiner(s): Alphonse, Fritz
• Application Number:
  US13/321,484
• Publication Number:
  US 20120131413A1
• Time in Patent Office: 1,575 Days
• Field of Search: 714/766, 714/758, 714/770, 714/799, 714/805, 714/710, 714/723, 714/761
• US Class Current: 714/766
• CPC Class Codes: G06F 11/073 in a memory management context, e.g. virtual memory or cache management memory management G06F12/00; testing of static memory units G11C29/00
• CPC Class Codes: G06F 11/0766 Error or fault reporting or storing
• CPC Class Codes: G06F 11/1008 in individual solid state devices G06F11/1004 takes precedence
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 29/52 Protection of memory contents; Detection of errors in memory contents
• CPC Class Codes: H03M 13/05 using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits H03M13/2906 takes precedence
• CPC Class Codes: H03M 13/13 Linear codes
• CPC Class Codes: H03M 13/6502 Reduction of hardware complexity or efficient processing

Abstract

In various embodiments, an apparatus, system, and method may increase data integrity in a redundant storage system. In one embodiment, a request is received for data stored at a storage system having a plurality of storage elements, where one or more of the plurality of storage elements include parity information. A determination is made that one of the plurality of storage elements is unavailable, the unavailable storage element being a functional storage element and including at least a portion of the data. Responsive to the determination, the data is reconstructed based on at least a portion of the parity information and data from one or more of the plurality of storage elements other than the unavailable storage element; a response is provided to the request such that the response includes the reconstructed data.

Claims

1. A method, comprising:

receiving a request for data stored at a storage system having a plurality of storage elements, wherein one or more of the plurality of storage elements include parity information;

determining that one of the plurality of storage elements is unavailable, wherein the unavailable storage element is a functional storage element and includes at least a portion of the data;

responsive to the determining;

reconstructing the data based on at least a portion of the parity information and data from one or more of the plurality of storage elements other than the unavailable storage element; and

providing a response to the request, wherein the response includes the reconstructed data.

2. The method of claim 1, wherein the plurality of storage elements are solid-state storage dies configured into one or more storage arrays.

3. The method of claim 2, wherein the reconstructed data is an error correcting code (ECC) chunk, and wherein the portion of the parity information is generated from the ECC chunk.

4. The method of claim 1, further comprising:

implementing a redundant array of independent drives (RAID) configuration across the plurality of storage elements, wherein implementing the RAID configuration includes generating and storing the parity information.

5. The method of claim 4, wherein the RAID configuration is implemented in a manner that supports a particular number of storage element failures without data loss, and wherein the method further comprises:

determining that a number of failed storage elements satisfies a threshold associated with the particular number; and

responsive to the determining, reconfiguring data in the plurality of storage elements such that a RAID stripe of the RAID configuration supports a greater number of storage element failures than the particular number.

6. The method of claim 1, further comprising:

tracking ones of the plurality of storage elements determined to be unavailable including maintaining a log file.

7. The method of claim 1, wherein the storage system includes a plurality of regions, and wherein the method further comprises:

organizing data based on performance requirements relative to a number of available storage elements within a given region.

8. An apparatus, comprising:

an availability module configured to identify at least a portion of a functional storage element as being unavailable;

a data regeneration module configured to regenerate data of the functional storage element based on data and parity information in one or more storage elements included within a storage array that includes the functional storage element; and

wherein the availability module and the data regeneration module are hardware circuits or memories having program instructions stored therein.

9. The apparatus of claim 8, wherein the apparatus is configured to service a request for data from another, available portion of the functional storage element.

10. The apparatus of claim 8, wherein the parity information supports failure of a particular number of storage elements, and wherein the apparatus further comprises:

a data reconfiguration module configured to reconfigure data within the storage array such that the parity information supports failure of an additional storage element, wherein the data reconfiguration module is a hardware circuit or memory having program instructions stored therein.

11. The apparatus of claim 8, wherein the apparatus is configured to store an error correcting code (ECC) in the storage array, wherein the ECC corresponds to data within the portion and is distinct from the parity information;

and

wherein the availability module is configured to identify the portion as being unavailable based on the ECC.

12. The apparatus of claim 11, wherein the apparatus is configured to:

generate an additional ECC from the regenerated data and the data in the one or more storage elements; and

store, within the storage array, the additional ECC and the regenerated data.

13. The apparatus of claim 12, wherein the apparatus is configured to store the portions of an ECC chunk including the additional ECC and the regenerated in separate erase blocks within the storage array.

14. The apparatus of claim 8, wherein the apparatus is configured to write data sequentially to storage elements within the storage array at an append point.

15. An apparatus, comprising:

a plurality of solid-state storage dies configured to implement a storage array that includes data and striped parity information corresponding to the data; and

a data regeneration module configured to regenerate data from an unavailable one of the plurality of solid-state storage dies based on the striped parity information and data from one or more available ones of the plurality of solid-state storage dies; and

wherein the data regeneration module is a hardware circuit or memory having program instructions stored therein.

16. The apparatus of claim 15, wherein the plurality of solid-state storage dies are within two or more vertically stacked chips.

17. The apparatus of claim 15, wherein the apparatus is configured to track a number of unavailable storage dies, and to reconfigure the striped parity information in response to the number of unavailable storage dies satisfying a threshold.

18. The apparatus of claim 15, wherein the apparatus is configured to receive a user input specifying that the storage die is unavailable.

19. The apparatus of claim 15, wherein the apparatus is configured to determine that the storage die is unavailable based on a number of read operations or a number of write operations performed to the storage die.

20. The apparatus of claim 15, wherein the data regeneration module is configured to perform regenerating the data in conjunction with performing a garbage collection process.