Determining the lineage of a content unit on an object addressable storage system

• US 8,135,760 B1
• Filed: 11/01/2007
• Issued: 03/13/2012
• Est. Priority Date: 11/01/2007
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Todd, Stephen, Hushon, Jr., John D.
• Primary Examiner(s): Alam, Shahid
• Assistant Examiner(s): LODHI, ANDALIB FT
• Application Number:
  US11/933,686
• Time in Patent Office: 1,594 Days
• Field of Search: 707/783, 707/792, 707/802, 707/812, 707/825
• US Class Current: 707/812
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06

Abstract

Embodiments of the invention relate to determining the lineage of a content unit stored on an object addressable storage (OAS) system. When a content unit that is derived from at least one other content unit is stored on an OAS system, metadata that identifies the source content unit(s) from which the at least one content unit was derived may be stored. This metadata may be subsequently used to determine the lineage of the content unit.

Claims

1. A method for use in a computer system, the method comprising acts of:

storing a first content unit on at least one object addressable storage (OAS) system;

storing a second content unit on the at least one OAS system;

using the at least one OAS system to;

identify the first content unit with a first object identifier that, from the perspective of an entity accessing the first content unit on the at least one OAS system, is independent of a first storage location of the first content unit on the at least one OAS system; and

identify the second content unit with a second object identifier that, from the perspective of an entity accessing the second content unit on the at least one OAS system, is independent of a second storage location of the second content unit on the at least one OAS system;

deriving content of the first content unit at least partially from content of the second content unit; and

storing on the at least one OAS system a third content unit that comprises;

the object identifier for the first content unit and metadata relating to the first content unit; and

the metadata identifying the second content unit as a source from which the content of the first content unit is at least partially derived.

2. The method of claim 1, wherein:

the at least one OAS system comprises at least one content addressable storage (CAS) system;

the first object identifier comprises a first content address that is generated, at least in part, based on at least a portion of the content of the first content unit; and

the second object identifier comprises a second content address that is generated, at least in part, based on at least a portion of the content of the second content unit.

3. The method of claim 1, wherein the OAS is system further used to:

identify the third content unit with a third object identifier that, from the perspective of an entity accessing the third content unit on the at least one OAS system, is independent of a third storage location of the third content unit on the at least one OAS system.

4. The method of claim 1, further comprising an act of:

storing, on the at least one OAS system, metadata identifying at least one algorithm used to derive the content of the first content unit from the content of the second content unit.

5. The method of claim 4, wherein the act of storing the metadata identifying the at least one algorithm used to derive the content of the first content unit from the content of the second content unit, further comprises an act of:

storing the metadata identifying the at least one algorithm in the third content unit.

6. A least one computer readable medium encoded with instructions that, when executed, perform a method for use in a computer system, the method comprising acts of:

storing a first content unit on at least one object addressable storage (OAS) system;

storing a second content unit on the at least one OAS system;

using the at least one OAS system to;

identify the first content unit with a first object identifier that, from the perspective of an entity accessing the first content unit on the at least one OAS system, is independent of a first storage location of the first content unit on the at least one OAS system; and

identify the second content unit with a second object identifier that, from the perspective of an entity accessing the second content unit on the at least one OAS system, is independent of a second storage location of the second content unit on the at least one OAS system;

deriving content of the first content unit at least partially from content of the second content unit; and

storing on the at least one OAS system a third content unit that comprises;

the object identifier for the first content unit and metadata relating to the first content unit; and

the metadata identifying the second content unit as a source from which the content of the first content unit is at least partially derived.

7. The at least one computer readable medium of claim 6, wherein:

the at least one OAS system comprises at least one content addressable storage (CAS) system;

the first object identifier comprises a first content address that is generated, at least in part, based on at least a portion of the content of the first content unit; and

the second object identifier comprises a second content address that is generated, at least in part, based on at least a portion of the content of the second content unit.

8. The at least one computer readable medium of claim 6, wherein the OAS system is further used to:

identify the third content unit with a third object identifier that, from the perspective of an entity accessing the third content unit on the at least one OAS system, is independent of a third storage location of the third content unit on the at least one OAS system.

9. The at least one computer readable medium of claim 6, wherein the method further comprises an act of:

storing, on the at least one OAS system, metadata identifying at least one algorithm used to derive the content of the first content unit from the content of the second content unit.

10. The at least one computer readable medium of claim 9, wherein the act of storing the metadata identifying the at least one algorithm used to derive the content of the first content unit from the content of the second content unit, further comprises an act of:

storing the metadata identifying the at least one algorithm in the third content unit.

11. At least one object addressable storage (OAS) system comprising:

at least one storage device; and

at least one controller that;

stores, on the at least one storage device, a first content unit and a second content unit, wherein the first and second content units are each identifiable to the at least one OAS system via an associated object identifier that, from the perspective of an entity accessing content units on the at least one OAS system, is independent of a storage location of the content unit on the at least one OAS system;

derives content of the first content unit at least partially from content of the second content unit;

stores, on the at least one storage device, a third content unit that comprises the object identifier for the first content unit and metadata relating to the first content unit, the metadata identifying the second content unit as a source from which the content of the first content unit is at least partially derived.

12. The at least one OAS system of claim 11, wherein the at least one OAS system comprises at least one content addressable storage (CAS) system, and wherein the object identifiers for the first and second content units each comprises a content address that is generated, at least in part, based on at least a portion of the content of its associated content unit.

13. The at least one OAS system of claim 11, wherein the third content unit is identifiable to the at least one OAS system via an associated object identifier that, from the perspective of an entity accessing content units on the at least one OAS system, is independent of a storage location of the third content unit on the at least one OAS system.

14. The at least one OAS system of claim 11, wherein the at least one controller:

stores, on the at least one storage device, metadata identifying at least one algorithm used to derive the content of the first content unit from the content of the second content unit.

15. The at least one OAS system of claim 14, wherein the at least one controller stores the metadata identifying the at least one algorithm in the third content unit.

16. A method comprising an act of:

determining, for a first content unit stored on at least one object addressable storage (OAS) system, at least one second content unit stored on the at least one OAS system from which the first content unit is derived by accessing metadata associated with the first content unit, wherein the first content unit and the at least one second content unit each is identifiable to the at least one OAS system via an associated object identifier that, from the perspective of an entity accessing content units on the at least one OAS system, is independent of a storage location of the content unit on the at least one OAS system, and wherein the metadata associated with the first content unit identifies the at least one second content unit from which the first content unit is derived via its object identifier, wherein the at least one OAS system comprises at least one content addressable storage (CAS) system, and wherein the object identifiers for the first content unit and the at least one second content unit each comprises a content address that is generated, at least in part, based on at least a portion of the content of its associated content unit.

17. The method of claim 16, wherein the metadata associated with the first content unit is stored in a third content unit on the at least one OAS system.

18. The method of claim 17, wherein the third content unit is identifiable to the at least one OAS system via an associated object identifier that, from the perspective of an entity accessing content units on the at least one OAS system, is independent of a storage location of the content unit on the at least one OAS system.

19. The method of claim 16, further comprising an act of:

determining at least one algorithm used to derive the first content unit from the at least one second content unit by accessing metadata associated with first content unit that identifies the at least one algorithm.

20. At least one non-transitory computer readable medium encoded with instructions that, when executed, perform a method comprising an act of:

determining, for a first content unit stored on at least one object addressable storage (OAS) system, at least one second content unit stored on the at least one OAS system from which the first content unit is derived by accessing metadata associated with the first content unit, wherein the first content unit and the at least one second content unit each is identifiable to the at least one OAS system via an associated object identifier that, from the perspective of an entity accessing content units on the at least one OAS system, is independent of a storage location of the content unit on the at least one OAS system, and wherein the metadata associated with the first content unit identifies the at least one second content unit from which the first content unit is derived via its object identifier and identifies an algorithm used to derive the first content unit from the second content unit, wherein the at least one OAS system comprises at least one content addressable storage (CAS) system, and wherein the object identifiers for the first content unit and the at least one second content unit each comprises a content address that is generated, at least in part, based on at least a portion of the content of its associated content unit.

21. The at least one non-transitory computer readable medium of claim 20, wherein the metadata associated with the first content unit is stored in a third content unit on the at least one OAS system.

22. The at least one non-transitory computer readable medium of claim 21, wherein the third content unit is identifiable to the at least one OAS system via an associated object identifier that, from the perspective of an entity accessing content units on the at least one OAS system, is independent of a storage location of the content unit on the at least one OAS system.

23. The at least one non-transitory computer readable medium of claim 20, wherein the method determining at least one algorithm used to derive the first content unit from the at least one second content unit by accessing metadata associated with first content unit that identifies the at least one algorithm.