MIGRATION IN A DISTRIBUTED FILE SYSTEM

• US 20090150460A1
• Filed: 12/07/2007
• Published: 06/11/2009
• Est. Priority Date: 12/07/2007
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: DARIMISETTY, Sivakumar, BALASUBRAMANIAN, Rajni, MCCLANAHAN, Edward D.
• Granted Patent: US 9,031,899 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/119 Details of migration of file systems migration mechanisms in storage systems G06F3/0647
• CPC Class Codes: G06F 16/1744 using compression, e.g. sparse files

Abstract

A method includes creating a temporary target s-stub file. The temporary target s-stub file points to a source share. The method further includes creating a plurality of stub files in a target top-level directory on a target share. Each stub file out of the plurality of stub files corresponds to source data. The source data includes files and subdirectories in a source top-level directory on a source share. The plurality of stub files include source information, the source information is associated with the temporary target s-stub file, and a source s-stub file points to the source share. The method further includes remapping the source s-stub to point to the target share.

Claims

1. A method comprising:

a) creating a temporary target s-stub file, the temporary target s-stub file pointing to a source share;

b) creating a plurality of stub files in a target top-level directory on a target share, each stub file out of the plurality of stub files corresponding to source data, the source data comprising files and subdirectories in a source top-level directory on a source share, the plurality of stub files comprising source information, the source information associated with the temporary target s-stub file, a source s-stub file pointing to the source share; and

c) remapping the source s-stub to point to the target share.

2. The method of claim 1, further comprising d) for each stub file, out of the plurality of stub files, corresponding to a file in the source top-level directory, copying the file in the source top-level directory into the target top-level directory, overwriting the stub file, thus creating target data.

3. The method of claim 2, further comprising e) for each stub file, out of the plurality of stub files, corresponding to a subdirectory in the source top-level directory, repeating b) and d) using a hidden directory on the target share as the target top-level directory and using the subdirectory as the source top-level directory, thus creating the target data in the hidden directory, deleting the stub file, and moving the target data out of the hidden directory and into the target top-level directory.

4. The method of claim 1, further comprising deleting the temporary target s-stub file.

5. The method of claim 1, further comprising:

freezing operations on the source top-level directory;

invalidating cached information about files copied from the source top-level directory; and

allowing operations to resume.

6. The method of claim 5, further comprising:

verifying each file and subdirectory in the source top-level directory corresponds to a stub file out of the plurality of stub files in the target top-level directory;

allowing operations to resume if verification fails, and

continuing to create the target top-level directory and verify until verification does not fail.

7. The method of claim 1, further comprising performing d) for source data that is the target of an access before the access occurs.

8. The method of claim 1, further comprising applying, to the target data, updates to the source data such that the target data becomes identical to the source data.

9. The method of claim 1, wherein creating the temporary target s-stub file comprises creating the temporary target s-stub file, the temporary target s-stub file pointing to a source share, the temporary target s-stub file unable to be remapped.

10. The method of claim 1, further comprising deleting the source top-level directory.

11. The method of claim 1, wherein the source share and the target share reside on different file servers.

12. The method of claim 1, further comprising determining the source data based on a life-cycle migration policy.

13. A computer-readable medium storing a software program that, when executed by a processor, causes the processor to:

a) create a temporary target s-stub file, the temporary target s-stub file pointing to a source share;

b) create a plurality of stub files in a target top-level directory on a target share, each stub file out of the plurality of stub files corresponding to source data, the source data comprising files and subdirectories in a source top-level directory on a source share, the plurality of stub files comprising source information, the source information associated with the temporary target s-stub file, a source s-stub file pointing to the source share; and

c) remap the source s-stub to point to the target share.

14. The computer-readable medium of claim 13, further causing the processor to d) for each stub file, out of the plurality of stub files, corresponding to a file in the source top-level directory, copy the file in the source top-level directory into the target top-level directory, overwriting the stub file, thus creating target data.

15. The computer-readable medium of claim 14, further causing the processor to e) for each stub file, out of the plurality of stub files, corresponding to a subdirectory in the source top-level directory, repeat b) and d) using a hidden directory on the target share as the target top-level directory and using the subdirectory as the source top-level directory, thus creating the target data in the hidden directory, deleting the stub file, and moving the target data out of the hidden directory and into the target top-level directory.

16. The computer-readable medium of claim 13, further causing the processor to delete the temporary target s-stub file.

17. The computer-readable medium of claim 13, further causing the processor to:

freeze operations on the source top-level directory;

invalidate cached information about files copied from the source top-level directory; and

allow operations to resume.

18. The computer-readable medium of claim 17, further causing the processor to:

verify each file and subdirectory in the source top-level directory corresponds to a stub file out of the plurality of stub files in the target top-level directory;

allow operations to resume if verification fails, and

continue to create the target top-level directory and verify until verification does not fail.

19. The computer-readable medium of claim 13, further causing the processor to perform d) for source data that is the target of an access before the access occurs.

20. The computer-readable medium of claim 13, further causing the processor to apply, to the target data, updates to the source data such that the target data becomes identical to the source data.

21. The computer-readable medium of claim 13, wherein creating the temporary target s-stub file causes the processor to create the temporary target s-stub file, the temporary target s-stub file pointing to a source share, the temporary target s-stub file unable to be remapped.

22. The computer-readable medium of claim 13, further causing the processor to delete the source top-level directory.

23. The computer-readable medium of claim 13, wherein the source share and the target share reside on different file servers.

24. The computer-readable medium of claim 13, further causing the processor to determine the source data based on a life-cycle migration policy.