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

• US 7,539,707 B2
• Filed: 11/15/2004
• Issued: 05/26/2009
• 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:
  US10/990,353
• Publication Number:
  US 20050193026A1
• Time in Patent Office: 1,653 Days
• Field of Search: 707/200, 707/201, 707/204, 707/205, 707/10
• US Class Current: 1/1
• 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 data in an information store at a first storage device at a first time;

selecting a first storage medium at a second storage device for storage of the data associated with the first snapshot, wherein the second storage device is separate from the first storage device;

storing the data associated with the first snapshot in the first storage medium;

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

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

selecting a 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;

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

tracking a location of the data associated with the first snapshot and the location in the information store of the tracked 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 the changes to 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 storage medium.