Content aligned block-based deduplication

• US 9,619,480 B2
• Filed: 08/07/2015
• Issued: 04/11/2017
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Vijayan, Manoj Kumar, Attarde, Deepak Raghunath, Viswanathan, Srikant
• Primary Examiner(s): Hoang, Son T
• Application Number:
  US14/821,418
• Publication Number:
  US 20160042007A1
• Time in Patent Office: 613 Days
• Field of Search: None
• CPC Class Codes: G06F 16/1748 De-duplication implemented within the file system, e.g. based on file segments de-duplication techniques in storage systems for the management of data blocks G06F3/0641
• CPC Class Codes: G06F 16/9014 hash tables
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0673 Single storage device

Abstract

A content alignment system according to certain embodiments aligns a sliding window at the beginning of a data segment. The content alignment system performs a block alignment function on the data within the sliding window. A deduplication block is established if the output of the block alignment function meets a predetermined criteria. At least part of a gap is established if the output of the block alignment function does not meet the predetermined criteria. The predetermined criteria is changed if a threshold number of outputs fail to meet the predetermined criteria.

Claims

1. A method for defining deduplication block alignments within a data segment, the method comprising:

iteratively performing a block alignment function on data within a sliding window in the data segment and, for each iterative performance of the block alignment function;

in response to determining that an output of the block alignment function performed on a current window of data satisfies one or more predetermined criteria;

establishing, with one or more computer processors, a deduplication data block having a predetermined block size; and

moving the sliding window relative to the data segment by an amount based at least in part on the predetermined block size before performing a next consecutive iteration; and

in response to determining that the output of the block alignment function performed on the current window of data does not satisfy the one or more predetermined criteria;

moving the sliding window relative to the data segment by an incremental amount that is distinct from the predetermined block size before performing the next consecutive iteration and without establishing a deduplication data block, wherein gaps of data not belonging to any deduplication data block exist between established deduplication data blocks following performance of the block alignment function across the data segment.

2. The method of claim 1, wherein each of the established deduplication data blocks has a same predetermined block size.

3. The method of claim 1, wherein the gaps of data comprise variable gap sizes.

4. The method of claim 1, further comprising changing at least one of the one or more predetermined criteria in response to determining, for a threshold number of consecutive iterations, that the output of the block alignment function performed on the data within the sliding window does not satisfy the one or more predetermined criteria.

5. The method of claim 4, wherein the one or more predetermined criteria comprise whether the output of the block alignment function falls within a predetermined range, and the changing the at least one of the one or more predetermined criteria comprises altering the predetermined range.

6. The method of claim 4, wherein the changing the at least one of the one or more predetermined criteria comprises altering the block alignment function.

7. The method of claim 6, wherein the block alignment function is a hash function and the altering the block alignment function comprises using a different hash function.

8. The method of claim 4, further comprising iteratively performing the block alignment function across at least a portion of the data segment again in response to the changing the at least one of the one or more predetermined criteria.

9. The method of claim 1, further comprising:

in response to determining, for a threshold number of consecutive iterations, that the output of the block alignment function performed on the current window of data does not satisfy the one or more predetermined criteria;

establishing the deduplication data block; and

moving the sliding window relative to the data segment by the incremental amount.

10. A deduplication system configured to define deduplication block alignments within a data segment, the system comprising:

one or more processors implemented at least partially by hardware; and

a deduplication block alignment module of executable instructions that when executed by the one or more processors, causes the one or more processors to iteratively perform a deduplication block alignment function on data within a sliding window in the data segment and, for each iterative performance of the deduplication block alignment function;

based at least in part on a determination that an output of the deduplication block alignment function performed on the data within the sliding window satisfies one or more predetermined criteria, establish a deduplication block having a predetermined block size and move the sliding window relative to the data segment by an amount based at least in part on the predetermined block size before performing a next consecutive iteration; and

based at least in part on a determination that the output of the deduplication block alignment function performed on the data within the sliding window does not satisfy the one or more predetermined criteria, define at least a portion of data not belonging to the deduplication block and move the sliding window relative to the data segment by an incremental amount that is different from the predetermined block size before performing the next consecutive iteration.

11. The system of claim 10, wherein the deduplication block alignment module when executed by the one or more processors further causes the one or more processors to change at least one of the one or more predetermined criteria in response to determining, for a threshold number of consecutive iterations, that the output of the deduplication block alignment function performed on the data within the sliding window does not satisfy the one or more predetermined criteria.

12. The system of claim 11, wherein the deduplication block alignment module when executed by the one or more processors further causes the one or more processors to perform the deduplication block alignment function across at least a portion of the data segment again in response to a criteria adjustment module changing the at least one of the one or more predetermined criteria.

13. The system of claim 11, wherein to change the at least one of the one or more predetermined criteria, the deduplication block alignment module when executed by the one or more processors further causes the one or more processors to alter the deduplication block alignment function.

14. A deduplication system configured to define deduplication block alignments within a data segment, the system comprising:

one or more processors implemented at least partially by hardware; and

a deduplication block alignment module of executable instructions that when executed by the one or more processors, causes the one or more processors to iteratively perform a deduplication block alignment function on data within a sliding window in the data segment and, for each iterative performance of the deduplication block alignment function determine whether an output of the deduplication block alignment function performed on the data within the sliding window satisfies one or more predetermined criteria, wherein

based at least in part on a determination that the output of the deduplication block alignment function performed on the data within the sliding window satisfies the one or more predetermined criteria, the deduplication block alignment module causes the one or more processors to establish a first deduplication block having a predetermined block size, and

based at least in part on a determination that the output of the deduplication block alignment function performed on a current window of data does not satisfy the one or more predetermined criteria for a threshold number of consecutive iterations, the deduplication block alignment module further causes the one or more processors to establish a second deduplication data block having the predetermined block size, and move the sliding window relative to the data segment by an incremental amount that is different from the predetermined block size.

15. A method for defining deduplication block alignments within a data segment, the method comprising:

iteratively performing a deduplication block alignment function on data within a sliding window in the data segment and, for each iterative performance of the deduplication block alignment function;

establishing, with one or more computer processors, a deduplication data block having a predetermined block size and moving the sliding window relative to the data segment by an amount that is based at least in part on the predetermined block size before performing a next consecutive iteration in response to determining that an output of the deduplication block alignment function performed on the data within the sliding window satisfies one or more predetermined criteria; and

defining, with the one or more computer processors, at least a portion of a gap of data not belonging to the deduplication data block and moving the sliding window relative to the data segment by an incremental amount that is different from the predetermined block size before performing the next consecutive iteration in response to determining that the output of the deduplication block alignment function performed on the data within the sliding window does not satisfy the one or more predetermined criteria.

16. The method of claim 15, further comprising changing the predetermined criteria in response to determining, for a threshold number of consecutive iterations, that the output of the deduplication block alignment function performed on the data within the sliding window does not satisfy the predetermined criteria.

17. The method of claim 16, further comprising iteratively performing the deduplication block alignment function across at least a portion of the data segment again in response to the changing the predetermined criteria.

18. A method for defining deduplication block alignments within a data segment, the method comprising:

iteratively performing a deduplication block alignment function on data within a sliding window in the data segment and, for each iterative performance of the deduplication block alignment function determining whether an output of the deduplication block alignment function performed on the data within the sliding window satisfies one or more predetermined criteria, wherein

based at least in part on a determination that the output of the deduplication block alignment function performed on the data within the sliding window satisfies one or more predetermined criteria, establishing, with one or more computer processors, a first deduplication data block having a predetermined block size, and

based at least in part on a determination that the output of the deduplication block alignment function performed on the data within the sliding window does not satisfy the one or more predetermined criteria, establishing, with the one or more computer processors, a second deduplication data block having the predetermined block size, and moving the sliding window relative to the data segment by an incremental amount that is different from the predetermined block size.