ACTIVE FILE INSTANT CLONING

• US 20110307456A1
• Filed: 03/30/2011
• Published: 12/15/2011
• Est. Priority Date: 06/14/2010
• Status: Active Grant

• Current Assignee: Quest Software, Inc.
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Jayaraman, Vinod, Rao, Goutham, Bolla, Ratna Manoj
• Granted Patent: US 8,396,843 B2
• Time in Patent Office: Days
• US Class Current: 707/692
• 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 16/1748 De-duplication implemented within the file system, e.g. based on file segments de-duplication techniques in storage systems for the management of data blocks G06F3/0641
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems

Abstract

Techniques and mechanisms are provided to instantly clone active files including active optimized files. When a new instance of an active file is created, a new stub is generated in the user namespace and a block map file is cloned. The block map file includes the same offsets and location pointers that existed in the original block map file. No user file data needs to be copied. If the cloned file is later modified, the behavior can be same as what happens when a de-duplicated file is modified.

Claims

1. A method, comprising:

receiving a request to create a new instance of an active and optimized file;

identifying a block map file associated with the active and optimized file, the block map file referencing a plurality of data segments in a datastore suitcase;

cloning the block map file associated with the active and optimized file, wherein a cloned block map file references the same plurality of data segments in the datastore suitcase;

cloning a stub file, wherein a cloned stub file appears in a user namespace as a file separate from the stub file.

2. The method of claim 1, wherein the active and optimized file is a virtual image associated with one of a plurality of virtual machines running on a system.

3. The method of claim 1, wherein the active and optimized file has been deduplicated.

4. The method of claim 1, wherein the active and optimized file has been compressed.

5. The method of claim 1, wherein the stub file is associated with extended attribute information in the user viewable namespace.

6. The method of claim 5, wherein the block map file is associated with the same extended attributed information in a user inaccessible locker.

7. The method of claim 1, wherein the cloned stub file is associated with extended attribute information in the user viewable namespace.

8. The method of claim 7, wherein the cloned block map file is associated with the same extended attribute information in the user inaccessible locker.

9. The method of claim 1, wherein the block map file includes offset, length, and location information pointing to data segments in a datastore suitcase.

10. The method of claim 9, wherein the cloned block map file includes the same offset, length, and location information pointing to the same data segments in the datastore suitcase.

11. A system, comprising:

an interface configured to receive a request to create a new instance of an active and optimized file;

a processor configured to identify a block map file associated with the active and optimized file, the block map file referencing a plurality of data segments in a datastore suitcase, the processor further configured to clone the block map file associated with the active and optimized file and clone the stub file, wherein a cloned block map file references the same plurality of data segments in the datastore suitcase and a cloned stub file appears in a user namespace as a file separate from the stub file.

12. The system of claim 11, wherein the active and optimized file is a virtual image associated with one of a plurality of virtual machines running on a system.

13. The system of claim 11, wherein the active and optimized file has been deduplicated.

14. The system of claim 11, wherein the active and optimized file has been compressed.

15. The system of claim 11, wherein the stub file is associated with extended attribute information in the user viewable namespace.

16. The system of claim 15, wherein the block map file is associated with the same extended attributed information in a user inaccessible locker.

17. The system of claim 11, wherein the cloned stub file is associated with extended attribute information in the user viewable namespace.

18. The system of claim 17, wherein the cloned block map file is associated with the same extended attribute information in the user inaccessible locker.

19. The system of claim 11, wherein the block map file includes offset, length, and location information pointing to data segments in a datastore suitcase.

20. An apparatus, comprising:

means for receiving a request to create a new instance of an active and optimized file;

means for identifying a block map file associated with the active and optimized file, the block map file referencing a plurality of data segments in a datastore suitcase;

means for cloning the block map file associated with the active and optimized file, wherein a cloned block map file references the same plurality of data segments in the datastore suitcase;

means for cloning a stub file, wherein a cloned stub file appears in a user namespace as a file separate from the stub file.