Detecting data integrity

• US 20060075287A1
• Filed: 10/06/2004
• Published: 04/06/2006
• Est. Priority Date: 10/06/2004
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ripberger, Richard Anthony, Hsu, Yu-Cheng, Jones, Michael John, Vageline, Michael P., Stelmach, Richard B.
• Granted Patent: US 7,577,804 B2
• Time in Patent Office: Days
• US Class Current: 714/5
• 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 3/0683 Plurality of storage devices

Abstract

Provided are a method, system, and article of manufacture for detecting data integrity. An indicator is written to invalidate a data block that is capable of being stored in a plurality of sectors of a storage device, wherein the indicator is written to the storage device in at least one sector that is not included in the plurality of sectors. A writing of entire contents of the data block to the plurality of sectors of the storage device is initiated, in response to the writing of the indicator. The indicator is updated to validate the data block, in response to a completion of the writing of the entire contents of the data block to the plurality of sectors of the storage device.

Claims

1. A method, comprising:

writing an indicator to invalidate a data block that is capable of being stored in a plurality of sectors of a storage device, wherein the indicator is written to the storage device in at least one sector that is not included in the plurality of sectors;

initiating a writing of entire contents of the data block to the plurality of sectors of the storage device, in response to the writing of the indicator; and

updating the indicator to validate the data block, in response to a completion of the writing of the entire contents of the data block to the plurality of sectors of the storage device.

2. The method of claim 1, wherein the indicator is a first indicator that is capable of validating the data block if at least one version of the entire contents of the data block has been completely written to the storage device, the method further comprising:

writing a second indicator to the at least one sector, wherein the second indicator indicates a version number of the data block.

3. The method of claim 2, the method further comprising:

reading the first indicator and the second indicator written to the at least one sector; and

determining that the data block is valid and has the version number indicated in the second indicator, in response to determining that the first indicator has validated the data block.

4. The method of claim 3, wherein the at least one sector and the plurality of sectors comprise a record, wherein the at least one sector is a first sector of the record, wherein the at least one sector comprises a record header, wherein the first indicator is a checkfield indicator comprising an error detection code, and wherein the second indicator is a generation count indicator.

5. The method of claim 1, further comprising:

receiving an interruption subsequent to the initiating of the writing of the entire contents of the data block and prior to the updating of the indicator to validate the data block; and

reading the indicator to determine whether the data block is invalid.

6. The method of claim 1, wherein the indicator indicates a version number of the data block, the method further comprising:

writing a new version number of the data block with the entire contents of the data block in the plurality of sectors of the data block, wherein the updating of the indicator to validate the data block further comprises writing the new version number of the data block to the indicator.

7. The method of claim 1, the method further comprising:

reading version numbers corresponding to the data block and the indicator; and

determining that the data block is valid if the version numbers corresponding to the data block and the indicator are the same.

8. The method of claim 1, the method further comprising:

reading version numbers corresponding to the data block and the indicator; and

determining that the data block is invalid if the version numbers corresponding to the data block and the indicator are different.

9. The method of claim 1, further comprising:

storing a plurality of versions and associated version numbers of a plurality of data blocks in a plurality of storage devices; and

comparing the version numbers of the plurality of data blocks to determine one data block with most recently updated data.

10. The method of claim 9, wherein the plurality of storage devices are RAID arrays, wherein the writing, the initiating, the updating, the storing, and the comparing are performed by a storage controller that is coupled to the RAID arrays by a plurality of device adapters.

11. The method of claim 1, wherein the writing, the initiating, and the updating are performed by a data integrity controller implemented in a computational device coupled to the storage device.

12. The method of claim 1, wherein the writing, the initiating, and the updating are performed by a data integrity controller implemented in the storage device.

13. The method of claim 1, wherein the entire contents of the data block comprise data corresponding to the data block, wherein the data is generated by a computational device for storing in the storage device, and wherein the entire contents do not include the indicator.

14. A system in communication with a storage device, the system comprising:

memory; and

;

circuitry coupled to the memory, wherein the circuitry is capable of performing operations, the operations comprising;

(i) writing an indicator to invalidate a data block that is capable of being stored in a plurality of sectors of the storage device, wherein the indicator is written to the storage device in at least one sector that is not included in the plurality of sectors;

(ii) initiating a writing of entire contents of the data block to the plurality of sectors of the storage device, in response to the writing of the indicator; and

(iii) updating the indicator to validate the data block, in response to a completion of the writing of the entire contents of the data block to the plurality of sectors of the storage device.

15. The system of claim 14, wherein the indicator is a first indicator that is capable of validating the data block if at least one version of the entire contents of the data block has been completely written to the storage device, the operations further comprising:

writing a second indicator to the at least one sector, wherein the second indicator indicates a version number of the data block.

16. The system of claim 15, the operations further comprising:

reading the first indicator and the second indicator written to the at least one sector; and

determining that the data block is valid and has the version number indicated in the second indicator, in response to determining that the first indicator has validated the data block.

17. The system of claim 16, wherein the at least one sector and the plurality of sectors comprise a record, wherein the at least one sector is a first sector of the record, wherein the at least one sector comprises a record header, wherein the first indicator is a checkfield indicator comprising an error detection code, and wherein the second indicator is a generation count indicator.

18. The system of claim 14, the operations further comprising:

receiving an interruption subsequent to the initiating of the writing of the entire contents of the data block and prior to the updating of the indicator to validate the data block; and

reading the indicator to determine whether the data block is invalid.

19. The system of claim 14, wherein the indicator indicates a version number of the data block, the operations further comprising:

writing a new version number of the data block with the entire contents of the data block in the plurality of sectors of the data block, wherein the updating of the indicator to validate the data block further comprises writing the new version number of the data block to the indicator.

20. The system of claim 14, the operations further comprising:

reading version numbers corresponding to the data block and the indicator; and

determining that the data block is valid if the version numbers corresponding to the data block and the indicator are the same.

21. The system of claim 14, the operations further comprising:

reading version numbers corresponding to the data block and the indicator; and

determining that the data block is invalid if the version numbers corresponding to the data block and the indicator are different.

22. The system of claim 14, wherein the system is in communication with a plurality of storage devices, the operations further comprising:

storing a plurality of versions and associated version numbers of a plurality of data blocks in the plurality of storage devices; and

comparing the version numbers of the plurality of data blocks to determine one data block with most recently updated data.

23. The system of claim 22, wherein the plurality of storage devices are RAID arrays coupled to a plurality of device adapters, wherein the system further comprises:

a storage controller implemented in the circuitry, wherein the writing, the initiating, the updating, the storing, and the comparing are performed by the storage controller, and wherein the storage controller is coupled to the RAID arrays by the plurality of device adapters.

24. The system of claim 14, the system further comprising:

a data integrity controller implemented in the circuitry, wherein the writing, the initiating, and the updating are performed by the data integrity controller.

25. The system of claim 14, wherein the system is included in the storage device and the communication is internal to the storage device, the system further comprising:

a data integrity controller implemented in the circuitry, wherein the writing, the initiating, and the updating are performed by a data integrity controller.

26. The system of claim 14, wherein the entire contents of the data block comprise data corresponding to the data block, wherein the data is generated by the system for storing in the storage device, and wherein the entire contents do not include the indicator.

27. An article of manufacture for detecting data integrity on a storage device, wherein the article of manufacture is capable of causing operations, the operations comprising:

writing an indicator to invalidate a data block that is capable of being stored in a plurality of sectors of the storage device, wherein the indicator is written to the storage device in at least one sector that is not included in the plurality of sectors;

initiating a writing of entire contents of the data block to the plurality of sectors of the storage device, in response to the writing of the indicator; and

updating the indicator to validate the data block, in response to a completion of the writing of the entire contents of the data block to the plurality of sectors of the storage device.

28. The article of manufacture of claim 27, wherein the indicator is a first indicator that is capable of validating the data block if at least one version of the entire contents of the data block has been completely written to the storage device, the operations further comprising:

writing a second indicator to the at least one sector, wherein the second indicator indicates a version number of the data block.

29. The article of manufacture of claim 28, the operations further comprising:

reading the first indicator and the second indicator written to the at least one sector; and

determining that the data block is valid and has the version number indicated in the second indicator, in response to determining that the first indicator has validated the data block.

30. The article of manufacture of claim 29, wherein the at least one sector and the plurality of sectors comprise a record, wherein the at least one sector is a first sector of the record, wherein the at least one sector comprises a record header, wherein the first indicator is a checkfield indicator comprising an error detection code, and wherein the second indicator is a generation count indicator.

31. The article of manufacture of claim 27, the operations further comprising:

receiving an interruption subsequent to the initiating of the writing of the entire contents of the data block and prior to the updating of the indicator to validate the data block; and

reading the indicator to determine whether the data block is invalid.

32. The article of manufacture of claim 27, wherein the indicator indicates a version number of the data block, the operations further comprising:

writing a new version number of the data block with the entire contents of the data block in the plurality of sectors of the data block, wherein the updating of the indicator to validate the data block further comprises writing the new version number of the data block to the indicator.

33. The article of manufacture of claim 27, the operations further comprising:

reading version numbers corresponding to the data block and the indicator; and

determining that the data block is valid if the version numbers corresponding to the data block and the indicator are the same.

34. The article of manufacture of claim 27, the operations further comprising:

reading version numbers corresponding to the data block and the indicator; and

determining that the data block is invalid if the version numbers corresponding to the data block and the indicator are different.

35. The article of manufacture of claim 27, the operations further comprising:

storing a plurality of versions and associated version numbers of a plurality of data blocks in a plurality of storage devices; and

comparing the version numbers of the plurality of data blocks to determine one data block with most recently updated data.

36. The article of manufacture of claim 35, wherein the plurality of storage devices are RAID arrays, wherein the writing, the initiating, the updating, the storing, and the comparing are performed by a storage controller that is coupled to the RAID arrays by a plurality of device adapters.

37. The article of manufacture of claim 27, wherein the writing, the initiating, and the updating are performed by a data integrity controller implemented in a computational device coupled to the storage device.

38. The article of manufacture of claim 27, wherein the writing, the initiating, and the updating are performed by a data integrity controller implemented in the storage device.

39. The article of manufacture of claim 27, wherein the entire contents of the data block comprise data corresponding to the data block, wherein the data is generated by a computational device for storing in the storage device, and wherein the entire contents do not include the indicator.