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

• US 8,645,320 B2
• Filed: 05/24/2012
• Issued: 02/04/2014
• 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, Rahual, Kumar, Avinash
• Primary Examiner(s): Corrielus, Jean M
• Application Number:
  US13/480,321
• Publication Number:
  US 20130006942A1
• Time in Patent Office: 621 Days
• Field of Search: 707/610, 707/639, 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 files in an information store at a first time, the one or more files being associated with clusters of data stored in the information store;

storing the first snapshot in computer storage that is separate from the information store;

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

comparing the second snapshot to the first snapshot to identify clusters of data associated with the one or more files that changed after the first time and before the second time;

storing the second snapshot and copies of the changed clusters of data in computer storage that is separate from the information store; and

automatically indexing the second snapshot, wherein said indexing includes storing data indicating that the copies of the changed clusters are stored in association with the second snapshot.

2. The method of claim 1, wherein the second snapshot is automatically indexed in a system catalog containing file system information.

3. The method of claim 1, wherein said automatically indexing includes storing data indicating where in the second storage device the copies of the changed clusters are stored.

4. The method of claim 1, wherein said automatically indexing the second snapshot includes identifying one or more previously saved snapshots where previous copies of the changed clusters were stored, if any.

5. The method of claim 1, wherein said automatically indexing the second snapshot includes storing file data indicating what files or folders the changed clusters are associated with.

6. The method of claim 5, wherein the file data includes a file name associated with one or more of the changed clusters.

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

8. 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.

9. An electronic file storage system configured to create snapshots for an information store, the system comprising:

computer hardware comprising one or more computer processors;

a storage manager module configured to execute in the one or more computer processors and configured to;

direct performance of a first snapshot of one or more files in an information store at a first time, the one or more files being associated with clusters of data stored in the information store;

store the first snapshot in a first storage device that is different than the information store;

direct performance of a second snapshot of the one or more files in the information store at a second time, the second time occurring after the first time;

compare the second snapshot to the first snapshot to identify clusters of data associated with the one or more files that changed after the first time and before the second time;

store the second snapshot and copies of the changed clusters of data in a second storage device that is different than the information store; and

automatically index the second snapshot, wherein said indexing includes storing data indicating that the copies of the changed clusters are stored in association with the second snapshot.

10. The system of claim 9, wherein the storage manager is configured to automatically index the second snapshot in a system catalog containing file system information.

11. The system of claim 9, wherein the storage manager is configured to automatically index the second snapshot at least partially by storing data indicating where in the second storage device the copies of the changed clusters are stored.

12. The system of claim 9, wherein the storage manager is configured to automatically index the second snapshot at least partially by identifying one or more previously-saved snapshots where previous copies of the changed clusters were stored, in any.

13. The system of claim 9, wherein the storage manager is configured to automatically index the second snapshot at least partially by storing file data indicating what files or folders the changed clusters are associated with.

14. The system of claim 13, wherein the file data includes a file name associated with one or more of the changed clusters.

15. The system of claim 9, wherein the storage manager is further configured to store copies of each of the one or more files in association with the first snapshot.

16. The method of claim 9, wherein the storage manager is further configured 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.

17. A computing system comprising:

an information store having clusters of data associated with a plurality of files stored thereon;

computer storage separate from the information store, the computer storage having stored thereon;

a first snapshot of the plurality of files, the first snapshot having been stored in the computer storage at a first time;

a second snapshot of the plurality of files, the second snapshot having been stored in the computer storage at a second time;

copies of clusters of data associated with the plurality of files that changed between the first time and the second time; and

an index of the second snapshot including data indicating that the copies of the changed clusters are stored in association with the second snapshot.