Synchronizing Updates Across Cluster Filesystems

• US 20160103850A1
• Filed: 12/15/2015
• Published: 04/14/2016
• Est. Priority Date: 11/29/2011
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Gupta, Karan, Naik, Manoj P., Schmuck, Frank B., Shah, Mansi A., Tewari, Renu
• Granted Patent: US 10,698,866 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity
• CPC Class Codes: G06F 16/2379 Updates performed during online database operations; commit processing

Abstract

The embodiments described herein relate to synchronization of data in a shared pool of configurable computer resources. One or more consistency points are created in a source filesystem. A first consistency point is compared with a second consistency point to detect a directory change at the source filesystem, which includes identifying at least one difference between the first and second consistency points. A file level change associated with an established directory at a target filesystem is identified responsive to the detection of the directory change. A link is established between the source filesystem and the target filesystem, and the established directory is updated based on the file level change.

Claims

1. A method comprising:

creating one or more consistency points in a source filesystem, including creating a first consistency point at a first point-in-time and a second consistency point at a second point-in-time, wherein each consistency point represents filesystem data and metadata at a point-in-time to establish a recovery point, and wherein the first consistency point and the second consistency point are any two consistency points;

comparing the first consistency point with the second consistency point to detect a directory change at the source filesystem, including identifying at least one difference between the first and second consistency points;

responsive to the detection of the directory change, identifying a file level change, wherein the file level change is associated with an established directory at a target filesystem;

establishing a link from the source filesystem to the target filesystem; and

updating the established directory based on the file level change.

2. The method of claim 1, wherein the comparison detects a presence of a new source filesystem inode, and wherein updating the established directory comprises mapping the new source filesystem inode to a target filesystem inode.

3. The method of claim 1, wherein updating the established directory comprises identifying filesystem operations on filesystem objects using file names.

4. The method of claim 1, further comprising generating an output file based on the comparison, and replaying the output file as a series of filesystem operations.

5. The method of claim 4, wherein the output file is replayed after communication failure between the source filesystem and the target filesystem.

6. The method of claim 1, wherein the source and target filesystems are heterogeneous filesystems.

7. The method of claim 1, further comprising reverting changes at the target filesystem by moving to an older consistency point.

8. The method of claim 1, further comprising creating a third consistency point in the source filesystem at a third point-in-time, the third consistency point being sequential with the first and second consistency point, and removing the first consistency point.

9. A system comprising:

a source server having a processing unit in communication with memory, wherein the source server is associated with a source filesystem;

a functional unit in communication with the source server, the functional unit to;

create one or more consistency points in a source filesystem, including create a first consistency point at a first point-in-time and a second consistency point at a second point-in-time, wherein each consistency point represents filesystem data and metadata at a point-in-time to establish a recovery point, and wherein the first consistency point and the second consistency point are any two consistency points;

compare the first consistency point with the second consistency point to detect a directory change at the source filesystem, including the functional unit to identify at least one difference between the first and second consistency points;

responsive to the detection of the directory change, identify a file level change, wherein the file level change is associated with an established directory at a target filesystem;

establish a link from the source filesystem to the target filesystem; and

update the established directory based on the file level change.

10. The system of claim 9, wherein the comparison detects a presence of a new source filesystem inode, and wherein updating the established directory comprises the functional unit to map the new source filesystem inode to a target filesystem inode.

11. The system of claim 9, wherein updating the established directory comprises the functional unit to identify filesystem operations on filesystem objects using file names.

12. The system of claim 9, further comprising the functional unit to generate an output file based on the comparison, and replay the output file as a series of filesystem operations, wherein the output file is replayed after communication failure between the source filesystem and the target filesystem.

13. The system of claim 9, wherein the source and target filesystems are heterogeneous filesystems.

14. The system of claim 9, further comprising the functional unit to revert changes at the target filesystem by moving to an older consistency point.

15. The system of claim 9, further comprising the functional unit to create a third consistency point in the source filesystem at a third point-in-time, the third consistency point being sequential with the first and second consistency point, and remove the first consistency point.

16. A computer program product comprising computer readable storage device having computer readable program code embodied therewith, the program code executable by a processor to:

create one or more consistency points in a source filesystem, including create a first consistency point at a first point-in-time and a second consistency point at a second point-in-time, wherein each consistency point represents filesystem data and metadata at a point-in-time to establish a recovery point, and wherein the first consistency point and the second consistency point are any two consistency points;

compare the first consistency point with the second consistency point to detect a directory change at the source filesystem, including the functional unit to identify at least one difference between the first and second consistency points;

responsive to the detection of the directory change, identify a file level change, wherein the file level change is associated with an established directory at a target filesystem;

establish a link from the source filesystem to the target filesystem; and

update the established directory based on the file level change.

17. The computer program product of claim 16, wherein the comparison detects a presence of a new source filesystem inode, and wherein updating the established directory comprises program code to map the new source filesystem inode to a target filesystem inode.

18. The computer program product of claim 16, wherein updating the established directory comprises program code to identify filesystem operations on filesystem objects using file names.

19. The computer program product of claim 16, further comprising program code to generate an output file based on the comparison, and replay the output file as a series of filesystem operations, wherein the output file is replayed after communication failure between the source filesystem and the target filesystem.

20. The computer program product of claim 16, further comprising the functional unit to create a third consistency point in the source filesystem at a third point-in-time, the third consistency point being sequential with the first and second consistency point, and remove the first consistency point.