Efficient data storage using two level delta resemblance

• US 20070239946A1
• Filed: 04/11/2006
• Published: 10/11/2007
• Est. Priority Date: 04/11/2006
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Data Domain, Inc. (Dell Technologies Inc.)
• Inventors: Zhu, Ming
• Granted Patent: US 7,949,824 B2
• Time in Patent Office: Days
• US Class Current: 711/154
• CPC Class Codes: G06F 11/1451 by selection of backup contents

Abstract

Storage using resemblance of data segments is disclosed. It is determined that a new segment resembles a second prior stored segment wherein the second prior stored segment is represented as a first stored delta and a first prior stored segment. A second delta between the new segment and the prior stored segment is determined. A representation of the new segment based at least in part on the second delta is stored.

Claims

1. A method of storage using resemblance of data segments comprising:

determining that a new segment resembles a second prior stored segment wherein the second prior stored segment is represented as a first stored delta and a first prior stored segment;

determining a second delta between the new segment and the prior stored segment; and

storing a representation of the new segment based at least in part on the second delta.

2. A method as in claim 1, wherein the second delta comprises a difference between the new segment and the second prior stored segment.

3. A method as in claim 1, wherein determining resemblance comprises comparing a summary feature set of the new segment with a summary feature set of the second prior stored segment.

4. A method as in claim 1, further comprising in the event that a new segment does not resemble the second prior stored segment, storing the new segment.

5. A method as in claim 1, wherein storing the representation of the new segment comprises storing the second delta, an indication of the first stored delta, and an indication of the first prior stored segment.

6. A method as in claim 1, wherein storing the representation of the new segment in the event that the second delta is larger than a predetermined threshold comprises storing the new segment.

7. A method as in claim 1, wherein storing the representation of the new segment in the event that the second delta is larger than a predetermined threshold and the new segment resembles the first prior stored segment comprises storing a third delta and an indication of the first prior stored segment.

8. A method as in claim 7, wherein the third delta comprises a difference between the new segment and the first prior stored segment.

9. A method as in claim 7, wherein determining resemblance comprises comparing a summary feature set of the new segment with a summary feature set of the first prior stored segment.

10. A method as in claim 1, wherein storing the representation of the new segment comprises storing the second delta combined with a fourth delta.

11. A method as in claim 7, wherein storing the representation of the new segment comprises storing the third delta combined with a fifth delta.

12. A method as in claim 1, wherein storing the representation of the new segment comprises locally compressing the new segment.

13. A method as in claim 1, wherein storing the representation of the new segment comprises locally compressing the second delta.

14. A method as in claim 7, wherein storing the representation of the new segment comprises locally compressing the third delta.

15. A method as in claim 1, wherein an identifier is computed for the new segment.

16. A method as in claim 1, wherein an identifier is computed for the new segment and comprises a fingerprint.

17. A method as in claim 1, wherein an identifier is computed for the new segment and comprises a serially generated number.

18. A method as in claim 1, wherein an identifier is computed for the second delta.

19. A method as in claim 1, wherein an identifier is computed for the second delta and comprises a fingerprint.

20. A method as in claim 1, wherein an identifier is computed for the second delta and comprises a serially generated number.

21. A method as in claim 7, wherein an identifier is computed for the third delta.

22. A method as in claim 7, wherein an identifier is computed for the third delta and comprises a fingerprint.

23. A method as in claim 7, wherein an identifier is computed for the third delta and comprises a serially generated number.

24. A method as in claim 1, wherein storing the representation of the new segment comprises packing the new segment in a container.

25. A method as in claim 1, wherein storing the representation of the new segment comprises packing the second delta in a container.

26. A method as in claim 7, wherein storing the representation of the new segment comprises packing the third delta in a container.

27. A method as in claim 1, wherein storing the representation of the new segment comprises storing the representation of the new segment in a backup storage system.

28. A method as in claim 1, wherein resemblance comprises a byte for byte similarity between the new segment and the second prior stored segment.

29. A method as in claim 1, wherein there is no loss of information in storing the new segment.

30. A computer program product for storage using resemblance of data segments, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

In the event that a new segment resembles a second prior stored segment wherein the second prior stored segment is represented as a first stored delta and a first prior stored segment, determining a second delta; and

storing a representation of the new segment based at least in part on the second delta.

31. A system for storage using resemblance of data segments comprising:

a processor; and

a memory coupled with the processor, wherein the memory is configured to provide the processor with instructions which when executed cause the processor to;

In the event that a new segment resembles a second prior stored segment wherein the second prior stored segment is represented as a first stored delta and a first prior stored segment, determine a second delta; and

store a representation of the new segment based at least in part on the second delta.