Backup of deduplicated data

• US 8,281,099 B2
• Filed: 01/03/2012
• Issued: 10/02/2012
• Est. Priority Date: 02/06/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kishi, Gregory Tad
• Primary Examiner(s): Nguyen, Hiep
• Application Number:
  US13/342,788
• Publication Number:
  US 20120109894A1
• Time in Patent Office: 273 Days
• Field of Search: None
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1453 using de-duplication of the data

Abstract

Computer program product to back up deduplicated data to data storage media, the deduplicated data comprising a plurality of data blocks referenced for deduplication. In one embodiment, the existence of multiple references to each of the data blocks is determined; and at least two copies of at least each data block having multiple references thereto is stored, each to a separate data storage media. In another embodiment, the references to each of the data blocks is determined; the total of multiple references is compared to a percentage threshold; and multiple copies are stored for all the data blocks where the percentage threshold is exceeded.

Claims

1. A computer program product for backing up deduplicated data from a deduplicated data source, said deduplicated data comprising a plurality of data blocks referenced for deduplication, said computer program product comprising a computer usable storage medium having non-transient program code for operating a processing system to perform the following steps:

determining the existence of multiple references to each of said data blocks; and

storing at least two copies of at least each said data block having multiple references thereto, each copy of said data block stored to separate data storage media.

2. A computer program product for backing up deduplicated data from a deduplication source, said deduplicated data comprising a plurality of data blocks referenced for deduplication, said computer program product comprising a computer usable storage medium having non-transient program code for operating a processing system to perform the following steps:

determining the references to each of said data blocks;

comparing said references to a reference threshold;

comprising storing a single copy of each said data block where said reference threshold is not exceeded; and

storing multiple copies of each said data block where said reference threshold is exceeded.

3. The computer program product of claim 2, wherein said multiple copy storing step comprises storing each copy of said multiple copies of a data block to each of separate data storage media.

4. The computer program product of claim 3, wherein said reference threshold comprises a number of references to a data block.

5. The computer program product of claim 4, wherein said deduplicated data is arranged in data volumes, at least one of said data volumes comprising a plurality of said data blocks, and wherein said determined references to a data block of said determination step excludes multiple references to a data block in the same said data volume.

6. The computer program product of claim 4, wherein said deduplicated data is arranged in data volumes, at least one of said data volumes comprising a plurality of said data blocks, and wherein said determined references to a data block of said determination step includes multiple references to a data block in the same said data volume.

7. The computer program product of claim 4, wherein said reference threshold number is one reference to a data block.

8. The computer program product of claim 3, wherein said reference threshold comprises a risk based threshold greater than one.

9. A computer program product for backing up deduplicated data from a deduplication source, said deduplicated data comprising a plurality of data blocks referenced for deduplication, said computer program product comprising a computer usable storage medium having non-transient program code for operating a processing system to perform the following steps:

determining the references to each of said data blocks in a context;

comparing the total of multiple said references in said context to a percentage threshold; and

comprising storing all of said data blocks of said context, where said percentage threshold is exceeded.

10. The computer program product of claim 9, wherein said deduplicated data is arranged in data volumes, at least one of said data volumes comprising a plurality of said data blocks;

wherein said percentage threshold comprises a percentage of data of a volume having multiple references to data blocks; and

wherein said storing step performed by a processing system comprises storing all said data blocks of said volume.

11. The computer program product of claim 10, wherein said percentage threshold comprises a percentage of the number of said data blocks of said volume.

12. The computer program product of claim 9, wherein said deduplicated data comprises a defined data stream comprising a plurality of data volumes;

wherein said percentage threshold comprises a percentage of data of said data stream having multiple references to data blocks; and

wherein said storing step performed by a processing system comprises storing all of said data of said data stream.

13. A computer program product for backing up deduplicated data from a deduplication source, said deduplicated data comprising a plurality of data blocks referenced for deduplication, said computer program product comprising a computer usable storage medium having non-transient program code for operating a processing system to perform the following steps:

determining the quantity of data of references to each of said data blocks in a context;

comparing the quantity of the data of said context to a percentage threshold; and

storing all of said data blocks of said context, where said percentage threshold is exceeded.

14. The computer program product of claim 13, wherein said deduplicated data is arranged in data volumes;

wherein said percentage threshold comprises a percentage of quantity of data of a volume; and

wherein said storing step performed by a processing system comprises storing all said data blocks of said volume.

15. The computer program product of claim 13, wherein said deduplicated data comprises a defined data stream comprising a plurality of data volumes;

wherein said percentage threshold comprises a percentage of the quantity of deduplicated data of said data stream; and

wherein said storing step performed by a processing system comprises storing all of said data of said data stream.

16. A computer program product for backing up deduplicated data from a deduplication source, said deduplicated data comprising a plurality of data blocks referenced for deduplication, said computer program product comprising a computer usable storage medium having non-transient program code for operating a processing system to perform the following steps:

determining the references to each of said data blocks;

comparing said references to a first threshold;

comparing said references to a second threshold;

storing a second copy of at least each said data block where said first threshold is exceeded; and

storing a copy in addition to said second copy of at least each said data block where said second threshold is exceeded.

17. The computer program product of claim 16, wherein said multiple copy storing step performed by a processing system comprises storing each copy of said second copy of a data block and each copy of said additional copy of a data block to each of separate data storage media.