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

• US 7,840,533 B2
• Filed: 04/30/2009
• Issued: 11/23/2010
• Est. Priority Date: 11/13/2003
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Ngo, David, Prahlad, Anand, Pawar, Rahual, Varadharajan, Prakash, Kumar, Avinash
• Primary Examiner(s): Corrielus; Jean M
• Application Number:
  US12/433,238
• Publication Number:
  US 20090240748A1
• Time in Patent Office: 572 Days
• Field of Search: 707/609, 707/610, 707/639
• 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 computer-implemented method of creating snapshots for an information store, wherein the information store is coupled via a computer network to at least a first storage medium and a second storage medium, the method comprising:

performing a first snapshot of data in an information store at a first time;

selecting the first storage medium for storage of the data associated with the first snapshot;

copying the data associated with the first snapshot to the first storage medium, wherein the first storage medium is different from the information store;

tracking changes to the data associated with the first snapshot, the changes occurring between the first time and a second time occurring after the first time;

performing at least a second snapshot of the data in the information store at the second time;

selecting the second storage medium for storage of the tracked changes to the data associated with the first snapshot, wherein the second storage medium is different from the information store; and

copying to the second storage medium the tracked changes to the data associated with the first snapshot, wherein the copying comprises using the second snapshot to identify a location in the information store of the changes to the data associated with the first snapshot.

2. The method of claim 1, wherein tracking changes to the data associated with the first snapshot comprises tracking changes to the data associated with the first snapshot using a block filter to identify changes to the data associated with the first snapshot and then storing data identifying a state of the data associated with the first snapshot in a data structure.

3. The method of claim 1, wherein tracking changes to the data associated with the first snapshot comprises tracking changes to the data associated with the first snapshot using a block filter to identify changes to the data associated with the first snapshot.

4. The method of claim 1, wherein the first storage medium and the second storage medium comprise the same physical storage medium.

5. The method of claim 1, wherein the steps of selecting the first storage medium or selecting the second storage medium comprises:

communicating with a storage management component to identify a media management component among multiple media management components according to a first selection criteria, wherein the identified media management component directs storage operations associated with multiple storage media; and

communicating with the identified media management component to select a storage medium among the multiple storage media according to a second selection criteria,

wherein the first selection criteria is related to available bandwidth, other storage operations, storage media availability, storage policies, or storage preferences.

6. The method of claim 1, wherein the steps of selecting the first storage medium or selecting the second storage medium comprises:

communicating with a storage management component to identify a media management component among multiple media management components according to a first selection criteria, wherein the identified media management component directs storage operations associated with multiple storage media; and

communicating with the identified media management component to select a storage medium among the multiple storage media according to a second selection criteria.

7. A system for creating snapshots, wherein the system is coupled via a computer network to at least a first storage medium and a second storage medium, the system comprising:

at least one processor;

an information store coupled to the processor;

means for performing a first snapshot of data in the information store at a first time;

means for selecting the first storage medium for storage of the data associated with the first snapshot;

means for copying the data associated with the first snapshot to the first storage medium, wherein the first storage medium is different from the information store;

means for tracking changes to the data associated with the first snapshot, the changes occurring between the first time and a second time occurring after the first time;

means for performing at least a second snapshot of the data in the information store at the second time;

means for selecting the second storage medium for storage of the tracked changes to the data associated with the first snapshot, wherein the second storage medium is different from the information store; and

means for copying to the second storage medium the tracked changes to the data associated with the first snapshot, wherein the copying comprises using the second snapshot to identify a location in the information store of the changes to the data associated with the first snapshot.

8. The system of claim 7, further comprising:

means for communicating with a storage management component to identify a media management component among multiple media management components according to a first selection criteria, wherein the identified media management component directs storage operations associated with multiple storage media; and

means for communicating with the identified media management component to select a storage medium among the multiple storage media according to a second selection criteria.

9. A computer-readable storage medium carrying instructions, which when performed by a processor, perform a method of creating snapshots for an information store, wherein the information store is coupled via a computer network to at least a first storage medium and a second storage medium, the method comprising:

at a first time, performing a first snapshot of data in an information store;

selecting the first storage medium for storage of the data associated with the first snapshot;

copying the data associated with the first snapshot to the first storage medium, wherein the first storage medium is different from the information store;

tracking changes to the data associated with the first snapshot, the changes occurring between the first time and a second time occurring after the first time;

at the second time, performing at least a second snapshot of the data in the information store;

selecting the second storage medium for storage of the tracked changes to the data associated with the first snapshot, wherein the second storage medium is different from the information store; and

copying to the second storage medium the tracked changes to the data associated with the first snapshot, wherein the copying comprises using the second snapshot to identify a location in the information store of the changes to the data associated with the first snapshot.

10. The computer-readable storage medium of claim 9, wherein tracking changes to the data associated with the first snapshot comprises tracking changes to the data associated with the first snapshot using a block filter to identify changes to the data associated with the first snapshot and then storing data identifying a state of the data associated with the first snapshot in a data structure.

11. The computer-readable storage medium of claim 9, wherein tracking changes to the data associated with the first snapshot comprises tracking changes to the data associated with the first snapshot using a block filter to identify changes to the data associated with the first snapshot.

12. The computer-readable storage medium of claim 9, wherein the first storage medium and the second storage medium comprise the same physical storage medium.

13. The computer-readable storage medium of claim 9, wherein the steps of selecting the first storage medium or selecting the second storage medium comprises:

communicating with a storage management component to identify a media management component among multiple media management components according to a first selection criteria, wherein the identified media management component directs storage operations associated with multiple storage media; and

communicating with the identified media management component to select a storage medium among the multiple storage media according to a second selection criteria,

wherein the first selection criteria is related to available bandwidth, other storage operations, storage media availability, storage policies, or storage preferences.

14. The computer-readable storage medium of claim 9, wherein the steps of selecting the first storage medium or selecting the second storage medium comprises:

communicating with a storage management component to identify a media management component among multiple media management components according to a first selection criteria, wherein the identified media management component directs storage operations associated with multiple storage media; and

communicating with the identified media management component to select a storage medium among the multiple storage media according to a second selection criteria.