IDENTIFYING APPLICATION METADATA IN A BACKUP STREAM

• US 20100077161A1
• Filed: 09/24/2008
• Published: 03/25/2010
• Est. Priority Date: 09/24/2008
• Status: Active Grant

• Current Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Original Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Inventors: Stoakes, Timothy John, Leppard, Andrew Charles
• Granted Patent: US 8,620,845 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 16/907 Retrieval characterised by using metadata, e.g. metadata not derived from the content or metadata generated manually

Abstract

A method of identifying application metadata in a backup stream comprises finding a known application metadata signature within a backup stream. A source application of user data in the backup stream is identified based upon the known application metadata signature. Application metadata, which has been generated by the source application, is removed from consideration by a data de-duplicator which is used to perform data de-duplication on the backup stream.

Claims

1. A computer-readable medium having computer-executable instructions stored thereon for performing a method of identifying application metadata in a backup stream, said method comprising:

finding a known application metadata signature within a backup stream;

identifying a source application of user data in said backup stream based upon said known application metadata signature; and

removing application metadata in said backup stream from consideration by a data de-duplicator which is used to perform data de-duplication on said backup stream, wherein said application metadata has been generated by said source application.

2. The computer readable medium of claim 1, wherein said finding a known application metadata signature within a backup stream comprises:

providing an a priori list of application metadata signatures, wherein said known metadata signature is included in said a priori list;

searching on said a priori list of application metadata signatures within said backup stream.

3. The computer readable medium of claim 2, wherein said searching on said a priori list of application metadata signatures within said backup stream comprises:

searching on a subset of said a priori list of application metadata signatures within said backup stream.

4. The computer readable medium of claim 1, wherein said finding a known application metadata signature within a backup stream comprises:

finding a known backup application metadata signature within said backup stream.

5. The computer readable medium of claim 1, wherein said finding a known application metadata signature within a backup stream comprises:

finding a known non-backup application metadata signature within said backup stream.

6. The computer readable medium of claim 1, wherein said finding a known application metadata signature within a backup stream comprises:

providing an a priori list of application metadata signatures;

generating an optimized string search data structure for a string search algorithm, said search data structure optimized from said a priori list of application metadata signatures; and

utilizing said string search algorithm to search on said search data structure within said backup stream.

7. The computer readable medium of claim 6, wherein said generating an optimized search data structure for a string search algorithm comprises:

generating said optimized search data structure for a string search algorithm selected from the group consisting of;

a Boyer-Moore-Horspool algorithm, a Knuth-Morris-Pratt algorithm, an Aho-Corasick algorithm, an Apostolico-Giancarlo algorithm, Commentz-Walter algorithm, and a Rabin-Karp algorithm.

8. The computer readable medium of claim 6, wherein said generating an optimized search data structure for a string search algorithm comprises:

generating a data structure in the form of a trie from said a priori list of application metadata signatures.

9. The computer readable medium of claim 1, wherein said removing application metadata in said backup stream from consideration by a data de-duplicator which is used to perform data de-duplication on said backup stream comprises:

editing said backup stream to remove said application metadata.

10. The computer readable medium of claim 1, wherein said removing application metadata in said backup stream from consideration by a data de-duplicator which is used to perform data de-duplication on said backup stream comprises:

providing an skip instruction to said data de-duplicator such that a location of said application metadata is ignored during data de-duplication of said backup stream.

11. The computer readable medium of claim 1, further comprising:

providing an informative instruction to said data de-duplicator regarding performance of data de-duplication on a portion of said user data.

12. An apparatus for identifying application metadata in a backup stream, said system comprising:

a metadata signature finder configured to find a known application metadata signature within a backup stream;

a source application identifier configured to identify a source application of user data in said backup stream based upon said known application metadata signature; and

a de-duplication delimitator configured to remove application metadata in said backup stream from consideration by a data de-duplicator which is used to perform data de-duplication on said backup stream, wherein said application metadata has been generated by said source application.

13. The apparatus of claim 12, wherein said metadata signature finder comprises:

an a priori list of application metadata signatures.

14. The apparatus of claim 12, wherein said metadata signature finder comprises:

a string search data structure optimized from an a priori list of application metadata signatures for a string search algorithm.

15. The apparatus of claim 14, wherein said metadata signature finder comprises:

a string searcher configured to search on said string search data structure within said backup stream.

16. The apparatus of claim 12 wherein said de-duplication delimitator comprises:

a delimitation instruction generator configured to provide a skip instruction to a data de-duplicator such that a location of said application metadata is ignored during data de-duplication of said backup stream.

17. The apparatus of claim 12 wherein said de-duplication delimitator comprises:

a data stream editor configured to automatically edit said backup stream to remove said application metadata.

18. A storage appliance comprising:

a plurality of storage devices;

a data de-duplicator coupled with said plurality of storage devices and configured for de-duplicating a backup stream prior to storing information from said backup stream on said plurality of storage devices; and

an application metadata identifier coupled with said data de-duplicator and configured for identifying application metadata within said backup stream, wherein said application metadata identifier comprises;

a metadata signature finder configured to find a known application metadata signature within said backup stream;

a source application identifier configured to identify a source application of user data in said backup stream based upon said known application metadata signature; and

a de-duplication delimitator configured to remove application metadata in said backup stream from consideration by said data de-duplicator during said de-duplicating, wherein said application metadata has been generated by said source application.

19. The storage appliance of claim 18, wherein said metadata signature finder includes:

an a priori list of application metadata signatures.

20. The storage appliance of claim 18, wherein said metadata signature finder comprises:

a string search data structure optimized from an a priori list of application metadata signatures for a string search algorithm.

21. The storage appliance of claim 20, wherein said string search data structure comprises a trie.

22. The storage appliance of claim 20, wherein said metadata signature finder comprises:

a string searcher configured to search on said string search data structure within said backup stream.