System and method for performing an image level snapshot and for restoring partial volume data

• US 8,886,595 B2
• Filed: 12/23/2013
• Issued: 11/11/2014
• Est. Priority Date: 11/13/2003
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Prahlad, Anand, Ngo, David, Varadharajan, Prakash, Pawar, Rahul S., Kumar, Avinash
• Primary Examiner(s): Corrielus, Jean M
• Application Number:
  US14/138,599
• Publication Number:
  US 20140181028A1
• Time in Patent Office: 323 Days
• Field of Search: 707/610, 707/639, 707/648, 707/649, 707/679, 711/162
• US Class Current: 707/610
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/1446 Point-in-time backing up or restoration of persistent data
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems
• CPC Class Codes: G06F 16/22 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: G06F 16/285 Clustering or classification
• CPC Class Codes: G06F 16/86 Mapping to a database
• CPC Class Codes: G06F 2201/80 Database-specific techniques
• CPC Class Codes: G06F 2201/805 Real-time
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

The present invention relates to a method for performing an image level copy of an information store. The present invention comprises performing a snapshot of an information store that indexes the contents of the information store, retrieving data associated with the contents of the information store from a file allocation table, copying the contents of the information store to a storage device based on the snapshot, and associating the retrieved data with the copied contents to provide file system information for the copied contents.

Claims

1. A method in a computing system of creating snapshots for an information store, the method comprising:

performing a first snapshot of one or more blocks of data stored in an information store;

obtaining first file information that maps the blocks of data in the first snapshot to one or more files;

storing the first snapshot in association with the first file information in one or more storage devices that are separate from the information store;

performing a second snapshot of the one or more blocks or data stored in the information store at a second time, the second time occurring after the first time;

identifying changed blocks of data in the second snapshot that changed after the first time and before the second time;

obtaining second file information that maps the changed blocks of data to the one or more files;

storing the second snapshot in association with the second file information in the one or more storage devices that are separate from the information store; and

automatically obtain copies of the changed blocks of data from the information store, and store the copies in association with the second snapshot and the second file information in the one or more storage devices that are separate from the information store.

2. The method of claim 1 wherein the second file information is obtained from a file access table.

3. The method of claim 1 wherein the second snapshot identifies where in the second storage device the copies of the changed blocks are stored.

4. The method of claim 1 wherein storing of the second snapshot automatically identifies one or more previously saved snapshots where previous copies of the changed blocks were stored.

5. The method of claim 1 wherein the second file information includes one or more file names associated with one or more of the changed blocks.

6. The method of claim 1 further comprising storing copies of each of the one or more files in association with the first snapshot.

7. The method of claim 1 further comprising identifying a plurality of snapshots stored in association with a copy of a first cluster or file, and restoring the first cluster or file at least partially by reading each of the copies of the first cluster or file.

8. The method of claim 1 wherein identifying the changed blocks uses a block filter to identify changes to the blocks of data that occur after the first shapshot.

9. The method of claim 1 further comprising identifying a plurality of snapshots stored in association with a copy of a first cluster or file, and restoring the first cluster or file at least partially by reading each of the copies of the first cluster or file.

10. The method of claim 1 wherein the blocks are stored in clusters.

11. A system configured to create snapshots for an information store, the system comprising:

at least one storage manager executing one or more first computers that direct one or more second computers to perform a first snapshot of one or more blocks of data stored in an information store;

the storage manager directs the one or more second computers to obtain first file information that maps the blocks of data in the first snapshot to one or more files;

the storage manager directs the one or more second computers to store the first snapshot in association with the first file information in one or more storage devices that are separate from the information store;

the storage manager directs the one or more second computers to perform a second snapshot of the one or more blocks or data stored in the information store at a second time, the second time occurring after the first time;

the storage manager directs the one or more second computers to identify changed blocks of data in the second snapshot that changed after the first time and before the second time;

the storage manager directs the one or more second computers to obtain second file information that maps the changed blocks of data to the one or more files;

the storage manager directs the one or more second computers to store the second snapshot in association with the second file information in the one or more storage devices that are separate from the information store; and

the storage manager directs the one or more second computers to automatically obtain copies of the changed blocks of data from the information store, and store the copies in association with the second snapshot and the second file information in the one or more storage devices that are separate from the information store.

12. The system of claim 11 wherein the second file information is obtained from a file access table.

13. The system of claim 11 wherein the second snapshot identifies where in the second storage device the copies of the changed blocks are stored.

14. The system of claim 11 the storage manager directs the one or more second computers during storage of the second snapshot to automatically identify one or more previously saved snapshots where previous copies of the changed blocks were stored.

15. The system of claim 11 wherein the second file information includes one or more file names associated with one or more of the changed blocks.

16. The system of claim 11 wherein the storage manager directs the one or more second computers to store copies of each of the one or more files in association with the first snapshot.

17. The system of claim 11 wherein the storage manager directs the one or more second computers to identify a plurality of snapshots stored in association with a copy of a first cluster or file, and restore the first cluster or file at least partially by reading each of the copies of the first cluster or file.

18. The system of claim 11 wherein identification of the changed blocks uses a block filter to identify changes to the blocks of data that occur after the first shapshot.

19. The system of claim 11 the storage manager directs the one or more second computers to identify a plurality of snapshots stored in association with a copy of a first cluster or file, and restoring the first cluster or file at least partially by reading each of the copies of the first cluster or file.

20. The system of claim 11 wherein the blocks are stored in clusters.