IMAGE LEVEL COPY OR RESTORE, SUCH AS IMAGE LEVEL RESTORE WITHOUT KNOWLEDGE OF DATA OBJECT METADATA

• US 20100076932A1
• Filed: 09/03/2009
• Published: 03/25/2010
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Lad, Kamleshkumar K.
• Granted Patent: US 8,725,688 B2
• Time in Patent Office: Days
• US Class Current: 707/639
• CPC Class Codes: G06F 11/1464 for networked environments
• 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 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

A system and method for performing an image level restore of data is described. In some examples, the system receives a request to restore a file and transmits the request to an intermediate component. The intermediate component may then retrieve a directory file from an image of a secondary copy of a data set, identify a location of the file from the directory file, and provide the location to the requestor.

Claims

1. A method in a computing system for restoring an individual file from a snapshot copy of a primary copy of a data set, the method comprising:

receiving at a file system a request to restore a file from a snapshot copy of a primary copy of a data set, wherein the snapshot copy represents the data set at a certain point in time;

transmitting from the file system to an intermediate component a request for a directory file that contains information associated with files imaged by the snapshot copy, wherein the directory file includes information identifying the files imaged by the snapshot and information identifying a location of the files imaged by the snapshot copy;

redirecting the request for the directory file, wherein the redirected request includes location information for the directory file obtained from the intermediate component;

receiving the directory file at the intermediate component;

communicating information associated with files contained within the directory file to the file system;

receiving a selection from the file system for the file to be restored, wherein the request is received at the intermediate component;

transferring location information for the file to the file system, wherein the location information is obtained from the directory file; and

transmitting from the file system a request for the file using the transferred location information.

2. The method of claim 1, wherein the transferred location information includes an identification of data blocks on media storing the file.

3. The method of claim 1 further comprising:

storing the received directory file in a cache associated with the intermediate component.

4. The method of claim 1, wherein redirecting the request includes:

at the intermediate component, retrieving a location for the directory file.

5. An intermediate component communicatively located between a restore component and a storage device, the intermediate component comprising:

a directory request module, wherein the directory request module is configured to;

receive a request from a restore component for a file imaged by a image level backup copy stored within the storage device; and

transmit a request to the storage device for a directory that includes information about files imaged by the image level backup copy; and

a location information retrieval module, wherein the location information retrieval module is configured to;

receive the directory from the storage device;

present files included in the directory to the restore component; and

transfer location information to the restore component for a presented file selected by the restore component, wherein the location information is contained within the received directory.

6. The intermediate component of claim 5, further comprising:

a cache module, wherein the cache module is configured to;

store the received directory or the location information for a predetermined time period after the request for the file was received; and

transfer the received directory or the location information stored in the cache module to the restore component when a request for a stored directory or file associated with the stored location information is received at the intermediate component.

7. A computer-readable storage medium containing code, which when executed by a computer causes a data restore system to perform a method of restoring data from a snapshot-based copy of the data, the method comprising:

receiving a request from a file system to restore data imaged by a snapshot stored on removable media;

intercepting the request at a virtual drive;

restoring, at the virtual drive, a data directory imaged by the snapshot, wherein the data directory includes an entry for the requested data;

extracting, at the virtual drive, location information associated with the storage media containing the requested data from the data directory; and

presenting the extracted location information to the file system.

8. The computer-readable storage medium of claim 7, wherein restoring a data directory includes retrieving information associated with contents of the snapshot to obtain location information for the data directory.

9. The computer-readable storage medium of claim 7, wherein the virtual drive is communicatively located between the file system that receives the request to restore data and a device driver that accesses the storage media storing the snapshot.

10. A method in a data storage system for obtaining access to a file imaged by a snapshot, the method comprising:

retrieving a directory file from a snapshot, wherein the directory file includes information identifying files imaged by the snapshot and information identifying locations of the files imaged by the snapshot;

identifying a file and a location for the file from the retrieved directory; and

accessing the identified file using the identified location.

11. The method of claim 10, further comprising:

receiving a request to restore the identified file; and

identifying the snapshot as being a snapshot containing an image of the identified file.

12. A computing system for restoring an individual file from an image level copy of a primary copy of a data set, the method comprising:

means for receiving a request to restore a file from an image level copy of a primary copy of a data set, wherein the image level copy is stored on removable media;

means for requesting a directory file from the image level copy, wherein the directory file contains information associated with files imaged by the image level copy, the information identifying the files imaged by the image level copy and identifying a location of the files imaged by the image level copy;

means for receiving and redirecting the request for the directory file to the image level copy, wherein the redirected request includes location information for the directory file obtained from the image level copy;

means for receiving the directory file from a location indicated by the location information;

means for displaying files contained within the directory file to the means for receiving a request;

means for receiving a selection for the file to be restored, wherein the selection is received at the means for receiving and redirecting; and

means for transferring location information for the file to the means for receiving a selection for the file, wherein the location information is obtained from the directory file.

13. The computing system of claim 12, wherein the means for displaying files includes:

means for displaying files tracked by the directory file; and

means for displaying files tracked by a file allocation table associated with the primary copy of the data set.

14. A method in a computing system for restoring a file from a snapshot-based secondary copy of data, the method comprising:

transmitting a request from a first component for a directory file to a storage device containing a snapshot-based secondary copy of data; and

transmitting a request from a second component different from the first component for a file imaged by the snapshot-based secondary copy of data;

wherein the requested file is included within the requested directory file.

15. The method of claim 14, wherein the first component includes a file system that provides a user interface to a user and receives the request from the user via the provided user interface.

16. The method of claim 14, further comprising:

receiving the request for the directory file via a user interface component configured to query a file system associated with the first component; and

presenting, via the user interface component, the requested file along with one or more files retrieved from a storage device associated with the queried file system.