Fast deduplication data verification

• US 9,940,059 B2
• Filed: 06/29/2016
• Issued: 04/10/2018
• Est. Priority Date: 09/16/2014
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Agrawal, Saurabh, Vijayan, Manoj Kumar
• Primary Examiner(s): Winder, Patrice
• Assistant Examiner(s): Aung, Aye M
• Application Number:
  US15/197,385
• Publication Number:
  US 20160306819A1
• Time in Patent Office: 650 Days
• CPC Class Codes: G06F 11/00 Error detection; Error correction; Monitoring error detection, correction or monitoring in information storage based on relative movement between record carrier and transducer G11B20/18; monitoring, i.e. supervising the progress of recording or reproducing G11B27/36; in static stores G11C29/00
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1464 for networked environments
• 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 16/1752 based on file chunks
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: G06F 16/215 Improving data quality; Data cleansing, e.g. de-duplication, removing invalid entries or correcting typographical errors
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

An information management system provides a data deduplication system that uses a primary table, a deduplication chunk table, and a chunk integrity table to ensure that a referenced deduplicated data block is only verified once during the data verification of a backup or other replication operation. The data deduplication system may reduce the computational and storage overhead associated with traditional data verification processes. The primary table, the deduplication chunk table, and the chunk integrity table, all of which are stored in a deduplication database, can also ensure synchronization between the deduplication database and secondary storage devices.

Claims

1. A networked information management system configured to verify deduplication information, the networked information management system comprising:

a storage manager comprising computer hardware configured to;

retrieve, from an electronically stored deduplication database, a chunk integrity table, wherein the chunk integrity table identifies a first data chunk, wherein the first data chunk is associated with a plurality of single instance file (SFile) containers, and wherein the chunk integrity table stores, for each SFile container in the plurality of SFile containers, an indication of whether the respective SFile container is verified;

retrieve, from a secondary storage subsystem, the first data chunk,

wherein the first data chunk comprises one or more data blocks;

for each data block in the first data chunk,

determine whether the respective data block comprises a link to one SFile container in the plurality of SFile containers;

perform a verification of the respective data block in response to a determination that the respective data block does not comprise the link; and

determine a verification status of the respective data block based on the indications of whether the SFile containers are verified stored in the chunk integrity table in response to a determination that the respective data block comprises the link.

2. The networked information management system of claim 1, wherein the chunk integrity table stores a zero bit for a first SFile container in the plurality of SFile containers, and wherein the zero bit indicates that the first SFile container is not verified.

3. The networked information management system of claim 2, wherein a first data block in the one or more data blocks comprises a link to the first SFile container, and wherein the verification status of the first data block comprises a fail status based on the zero bit stored in the chunk integrity table for the first SFile container.

4. The networked information management system of claim 1, wherein the chunk integrity table stores a one bit for a first SFile container in the plurality of SFile containers, and wherein the one bit indicates that the first SFile container is verified.

5. The networked information management system of claim 4, wherein a first data block in the one or more data blocks comprises a link to the first SFile container, and wherein the verification status of the first data block comprises a pass status based on the one bit stored in the chunk integrity table for the first SFile container.

6. The networked information management system of claim 1, wherein the computer hardware is further configured to retrieve the chunk integrity table in response to a request to verify data in a backup.

7. The networked information management system of claim 6, wherein the computer hardware is further configured to cause the chunk integrity table to be deleted from the electronically stored deduplication database after verification of the data in the backup is complete.

8. The networked information management system of claim 1, wherein a first data block in the one or more data blocks is verified if the first data block is readable, decompressible, and decryptable.

9. The networked information management system of claim 1, wherein the chunk integrity table allows the storage manager to verify an integrity of the first data chunk without having to perform a verification of each data block in the one or more data blocks that comprises a link to one SFile container in the plurality of SFile containers more than once.

10. The networked information management system of claim 1, wherein the chunk integrity table identifies the first data chunk and a set of other data chunks.

11. The networked information management system of claim 10, wherein the computer hardware is further configured to perform a verification of one or more other data blocks of the set of other data chunks using the chunk integrity table.

12. A computer-implemented method for verifying deduplication information, the computer-implemented method comprising:

retrieving, from an electronically stored deduplication database, a chunk integrity table, wherein the chunk integrity table identifies a first data chunk, wherein the first data chunk is associated with a plurality of single instance file (SFile) containers, and wherein the chunk integrity table stores, for each SFile container in the plurality of SFile containers, an indication of whether the respective SFile container is verified;

retrieving, from a secondary storage subsystem, the first data chunk, wherein the first data chunk comprises one or more data blocks;

for each data block in the first data chunk,

determining whether the respective data block comprises a link to one SFile container in the plurality of SFile containers;

performing a verification of the respective data block in response to a determination that the respective data block does not comprise the link; and

determining a verification status of the respective data block based on the indications of whether the SFile containers are verified stored in the chunk integrity table in response to a determination that the respective data block comprises the link.

13. The computer-implemented method of claim 12, wherein the chunk integrity table stores a zero bit for a first SFile container in the plurality of SFile containers, and wherein the zero bit indicates that the first SFile container is not verified.

14. The computer-implemented method of claim 13, wherein a first data block in the one or more data blocks comprises a link to the first SFile container, and wherein the verification status of the first data block comprises a fail status based on the zero bit stored in the chunk integrity table for the first SFile container.

15. The computer-implemented method of claim 12, wherein the chunk integrity table stores a one bit for a first SFile container in the plurality of SFile containers, and wherein the one bit indicates that the first SFile container is verified.

16. The computer-implemented method of claim 15, wherein a first data block in the one or more data blocks comprises a link to the first SFile container, and wherein the verification status of the first data block comprises a pass status based on the one bit stored in the chunk integrity table for the first SFile container.

17. The computer-implemented method of claim 12, further comprising retrieving the chunk integrity table in response to a request to verify data in a backup.

18. The computer-implemented method of claim 17, further comprising causing the chunk integrity table to be deleted from the electronically stored deduplication database after verification of the data in the backup is complete.

19. The computer-implemented method of claim 12, wherein a first data block in the one or more data blocks is verified if the first data block is readable, decompressible, and decryptable.

20. The computer-implemented method of claim 12, wherein the chunk integrity table allows for verification of an integrity of the first data chunk without having to perform a verification of each data block in the one or more data blocks that comprises a link to one SFile container in the plurality of SFile containers more than once.