Managing redundant immutable files using deduplication in storage clouds

• US 8,892,521 B2
• Filed: 05/10/2013
• Issued: 11/18/2014
• Est. Priority Date: 12/02/2011
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chhaunker, Gaurav, Jain, Bhushan P., Patil, Sandeep R., Ramanathan, Sri, Trevathan, Matthew B.
• Primary Examiner(s): HO, BINH VAN
• Application Number:
  US13/891,589
• Publication Number:
  US 20130246357A1
• Time in Patent Office: 557 Days
• Field of Search: 707/654
• US Class Current: 707/654
• CPC Class Codes: G06F 16/00 Information retrieval; Database structures therefor; File system structures therefor
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/162 Delete operations erasing in storage systems G06F3/0652
• CPC Class Codes: G06F 16/174 Redundancy elimination performed by the file system management of the data involved in backup or backup restore using de-duplication of the data G06F11/14
• 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 16/182 Distributed file systems
• CPC Class Codes: G06F 16/2379 Updates performed during online database operations; commit processing
• CPC Class Codes: G06F 7/00 Methods or arrangements for processing data by operating upon the order or content of the data handled logic circuits H03K19/00
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]

Abstract

A method includes receiving a request to save a first file as immutable. The method also includes searching for a second file that is saved and is redundant to the first file. The method further includes determining the second file is one of mutable and immutable. When the second file is mutable, the method includes saving the first file as a master copy, and replacing the second file with a soft link pointing to the master copy. When the second file is immutable, the method includes determining which of the first and second files has a later expiration date and an earlier expiration date, saving the one of the first and second files with the later expiration date as a master copy, and replacing the one of the first and second files with the earlier expiration date with a soft link pointing to the master copy.

Claims

1. A method of file deduplication implemented in a computer infrastructure comprising a combination of hardware and software, the method comprising:

receiving a request to save a first file as immutable;

searching for a second file that is saved and is redundant to the first file;

determining the second file is one of mutable and immutable;

when the second file is mutable, saving the first file as a master copy, and replacing the second file with a soft link pointing to the master copy; and

when the second file is immutable, determining which of the first and second files has a later expiration date and an earlier expiration date, saving the one of the first and second files with the later expiration date as a master copy, and replacing the one of the first and second files with the earlier expiration date with a soft link pointing to the master copy.

2. The method of claim 1, wherein the request to save the first file comprises a request or instruction to save the first file in a shared storage.

3. The method of claim 2, wherein:

the request to save the first file is received from a local computing device; and

the shared storage is in a cloud environment remote from the local computing device.

4. The method of claim 1, wherein the searching for the second file comprises comparing a hash value of the first file to hash values of other saved files.

5. The method of claim 1, wherein the searching for the second file comprises:

determining at least one candidate redundant file by comparing a hash value of the first file to hash values of other saved files; and

comparing the first file to the at least one candidate redundant file using a file diff process.

6. The method of claim 1, wherein the later expiration date and the earlier expiration date are immutability expiration dates.

7. The method of claim 1, wherein:

the second file is immutable; and

the soft link contains data defining the earlier expiration date.

8. The method of claim 1, wherein:

the second file is immutable;

the second file has the earlier expiration date; and

the replacing comprises deleting a saved copy of the second file.

9. The method of claim 1, wherein:

the second file is mutable;

the master copy is saved in a shared storage of a cloud environment; and

the second file is deleted from the shared storage the soft link points to the master copy.

10. The method of claim 1, wherein a service provider at least one of creates, maintains, deploys and supports the computer infrastructure.

11. The method of claim 1, wherein steps of claim 1 are provided by the service provider on a subscription, advertising, and/or fee basis.