Recording file events in change logs while incrementally backing up file systems

• US 9,645,892 B1
• Filed: 07/08/2014
• Issued: 05/09/2017
• Est. Priority Date: 07/08/2014
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: Patwardhan, Kedar S.
• Primary Examiner(s): Wong, Leslie
• Application Number:
  US14/325,690
• Time in Patent Office: 1,036 Days
• Field of Search: 707618, 707624, 707626, 707646, 707745
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1466 to make the backup process non-disruptive
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery

Abstract

Recording file events in change logs while incrementally backing up file systems is described. A system begins incrementally backing up a file system by reading a current change log. The system identifies a file event associated with the file system while incrementally backing up the file system. The system identifies a unique identifier associated with the file event. The system determines whether the unique identifier associated with the file event is greater than a unique identifier offset associated with reading the current change log. The system records the file event in the current change log in response to a determination that the unique identifier associated with the file event is greater than the unique identifier associated with reading the current change log.

Claims

1. A system for recording file events in change logs while incrementally backing up file systems, the system comprising:

a processor-based application, which executed on a computer, will cause the processor to;

back up a file system incrementally by reading a current change log;

identify a file event associated with the file system, the file event occurring during the incremental back up of the file system;

identify a unique identifier associated with the identified file event;

determine whether the unique identifier associated with the file event is greater than a unique identifier associated with reading the current change log; and

record the file event in the current change log during the incremental backup of the file system in response to a determination that the unique identifier associated with the file event is greater than the unique identifier associated with reading the current change log.

2. The system of claim 1, wherein reading the current change log comprises reading the current change log in an order based on an increasing sequence of index node number offsets.

3. The system of claim 1, wherein the current change log records file events which occurred since a most recent back up of the file system.

4. The system of claim 1, wherein the file event comprises one of a file creation, a file modification, and a file deletion.

5. The system of claim 1, wherein the processor-based application, when executed, will further cause the processor to record the file event in a new change log in response to a determination that the unique identifier associated with the file event is not greater than the unique identifier associated with reading the current change log.

6. The system of claim 1, wherein the processor-based application, when executed, will further cause the processor to record subsequent file events to a new change log after incrementally backing up the file system is completed.

7. The system of claim 1, wherein the processor-based application, when executed, will further cause the processor to delete the current change log after incrementally backing up the file system is completed.

8. A computer-implemented method for recording file events in change logs while incrementally backing up file systems, the method comprising:

backing up a file system incrementally by reading a current change log;

identifying a file event associated with the file system, the file event occurring during the incremental back up of the file system;

identifying a unique identifier associated with the identified file event;

determining whether the unique identifier associated with the file event is greater than a unique identifier associated with reading the current change log; and

recording the file event in the current change log during the incremental backup of the file system in response to a determination that the unique identifier associated with the file event is greater than the unique identifier associated with reading the current change log.

9. The method of claim 8, wherein reading the current change log comprises reading the current change log in an order based on an increasing sequence of index node number offsets.

10. The method of claim 8, wherein the current change log records file events which occurred since a most recent back up of the file system.

11. The method of claim 8, wherein the file event comprises one of a file creation, a file modification, and a file deletion.

12. The method of claim 8, wherein the method further comprises recording the file event in a new change log in response to a determination that the unique identifier associated with the file event is not greater than the unique identifier associated with reading the current change log.

13. The method of claim 8, wherein the method further comprises recording subsequent file events to a new change log and deleting the current change log after incrementally backing up the file system is completed.

14. A computer program product, comprising a non-transitory computer-readable medium having a computer-readable program code embodied therein to be executed by one or more processors, the program code including instructions to:

back up a file system incrementally by reading a current change log;

identify a file event associated with the file system, the file event occurring during the incremental back up of the file system;

identify a unique identifier associated with the identified file event;

determine whether the unique identifier associated with the file event is greater than a unique identifier associated with reading the current change log; and

record the file event in the current change log during the incremental backup of the file system in response to a determination that the unique identifier associated with the file event is greater than the unique identifier associated with reading the current change log.

15. The computer program product of claim 14, wherein reading the current change log comprises reading the current change log in an order based on an increasing sequence of index node number offsets.

16. The computer program product of claim 14, wherein the current change log records file events which occurred since a most recent back up of the file system.

17. The computer program product of claim 14, wherein the file event comprises one of a file creation, a file modification, and a file deletion.

18. The computer program product of claim 14, wherein the program code includes further instructions to record the file event in a new change log in response to a determination that the unique identifier associated with the file event is not greater than the unique identifier associated with reading the current change log.

19. The computer program product of claim 14, wherein the program code includes further instructions to record subsequent file events to a new change log after incrementally backing up the file system is completed.

20. The computer program product of claim 14, wherein the program code includes further instructions to delete the current change log after incrementally backing up the file system is completed.