File deletion and truncation using a zombie file space

• US 20050033775A1
• Filed: 06/15/2004
• Published: 02/10/2005
• Est. Priority Date: 08/18/2000
• Status: Active Grant

• Current Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Edwards, John K., Patel, Kayuri, Chen, Ray
• Granted Patent: US 7,451,165 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 16/162 Delete operations erasing in storage systems G06F3/0652
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency ensuring consistency in mirrored systems G06F11/2064
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99956 File allocation

Abstract

A method and system for reliably performing extra-long operations in a reliable state-full system (such as a file system). The file system includes a separate portion of the file system reserved for files having extra-long operations in progress, including file deletion and file truncation. This separate portion of the file system is called the zombie file space; it includes a separate name space from the regular (“live”) file system that is accessible to users, and is maintained as part of the file system when recording a consistency point.

Claims

1. A method of operating a file server, comprising the steps of:

identifying a file in a first file space for truncation using zombie space inaccessible to one or more system users;

making said file unavailable to the one or more system users in the first file space;

linking said file to the zombie file space;

truncating said file while maintaining file consistency between check-pointed intervals;

delinking said file from said zombie file space; and

making said file available to the one or more system users in said first file space.

2. The method of claim 1, wherein the step of identifying comprises:

receiving a selection of said file from a user; and

identifying said file for truncation using zombie space based on parameter-based file size comparison.

3. The method of claim 2, wherein the step of truncating is performed after the step of linking and before the step of delinking.

4. A method of operating a file server, comprising the steps of:

identifying a file in a first file space for deletion using zombie space inaccessible to one or more system users;

making said file unavailable to the one or more system users in the first file space;

linking said file to the zombie file space;

deleting said file while maintaining file consistency between check-pointed intervals; and

delinking said file from said zombie file space.

5. The method of claim 4, wherein the step of identifying comprises:

receiving a selection of said file from a user; and

identifying said file for truncation using zombie space based on parameter-based file size comparison.

6. The method of claim 5, wherein the step of deleting is performed after the step of linking and before the step of delinking.

7. The method of claim 5, wherein said file is a composite file comprising one or more attached data elements.

8. The method of claim 7, wherein the step of deleting comprises:

deleting at least one of the one or more attached data elements after the step of linking and before the step of delinking; and

deleting said file after the step of delinking.

9. A file server, comprising:

a processor;

memory storing program code;

a network interface; and

mass storage;

wherein said processor executes the program code stored in said memory to control access to said mass storage, the program code comprising instructions that, when executed by the processor, cause the server to perform the steps of;

identifying a file in a first file space for truncation using zombie space inaccessible to one or more system users;

making said file unavailable to the one or more system users in the first file space;

linking said file to the zombie file space;

truncating said file while maintaining file consistency between check-pointed intervals;

delinking said file from said zombie file space; and

making said file available to the one or more system users in said first file space.

10. The server of claim 9, wherein the instructions, when executed by the processor, cause the server to perform at least the following steps in the course of performing the step of identifying:

receiving a selection of said file from a user; and

identifying said file for truncation using zombie space based on parameter-based file size comparison.

11. The server of claim 10, wherein the server performs the step of truncating after the step of linking and before the step of delinking.

12. A file server, comprising:

a processor;

memory storing program code;

a network interface; and

mass storage;

wherein said processor executes the program code stored in said memory to control access to said mass storage, the program code comprising instructions that, when executed by the processor, cause the server to perform the steps of;

identifying a file in a first file space for deletion using zombie space inaccessible to one or more system users;

making said file unavailable to the one or more system users in the first file space;

linking said file to the zombie file space;

deleting blocks of said file while maintaining file consistency between check-pointed intervals; and

delinking said file from said zombie file space.

13. The server of claim 12, wherein the instructions, when executed by the processor, cause the server to perform at least the following steps in the course of performing the step of identifying:

receiving a selection of said file from a user; and

identifying said file for truncation using zombie space based on parameter-based file size comparison.

14. The server of claim 13, wherein the server performs the step of deleting after the step of linking and before the step of delinking.

15. The method of claim 13, wherein said file is a composite file comprising one or more attached data elements.

16. The method of claim 15, wherein the instructions, when executed by the processor, cause the server to perform at least the following steps in the course of performing the step of deleting:

deleting at least one of the one or more attached data elements after the step of linking and before the step of delinking; and

deleting said file after the step of delinking.

17. A memory storing program code that, when performed by a processor of a file server, causes the server to perform the steps of:

identifying a file in a first file space for truncation using zombie space inaccessible to one or more system users;

making said file unavailable to the one or more system users in the first file space;

linking said file to the zombie file space;

truncating said file while maintaining file consistency between check-pointed intervals;

delinking said file from said zombie file space; and

making said file available to the one or more system users in said first file space.

18. The memory of claim 17, wherein the instructions, when executed by the processor, cause the server to perform at least the following steps in the course of performing the step of identifying:

receiving a selection of said file from a user; and

identifying said file for truncation using zombie space based on parameter-based file size comparison.

19. The memory of claim 18, wherein the server performs the step of truncating after the step of linking and before the step of delinking.

20. A memory storing program code that, when performed by a processor of a file server, causes the server to perform the steps of:

identifying a file in a first file space for deletion using zombie space inaccessible to one or more system users;

making said file unavailable to the one or more system users in the first file space;

linking said file to the zombie file space;

deleting blocks of said file while maintaining file consistency between check-pointed intervals; and

delinking said file from said zombie file space.

21. The memory of claim 20, wherein the instructions, when executed by the processor, cause the server to perform at least the following steps in the course of performing the step of identifying:

receiving a selection of said file from a user; and

identifying said file for truncation using zombie space based on parameter-based file size comparison.

22. The memory of claim 21, wherein the server performs the step of deleting after the step of linking and before the step of delinking.

23. The memory of claim 21, wherein said file is a composite file comprising one or more attached data elements.

24. The memory of claim 23, wherein the instructions, when executed by the processor, cause the server to perform at least the following steps in the course of performing the step of deleting:

deleting at least one of the one or more attached data elements after the step of linking and before the step of delinking; and

deleting said file after the step of delinking.