Snapshot of a file system

• US 20040088301A1
• Filed: 10/31/2002
• Published: 05/06/2004
• Est. Priority Date: 10/31/2002
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Xu, Zhichen, Mahalingam, Mallik, Tang, Chunqiang
• Application Number:
  US10/284,109
• Publication Number:
  US 20040088301A1
• Time in Patent Office: Days
• US Class Current: 707/100
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

A method for generating a snapshot of a file system operable to store a plurality of objects includes receiving a snapshot time identifying a point in time in a history of the file system. The method further includes identifying at least one object available at the snapshot time.

Claims

1. A method for generating a snapshot of a file system operable to store a plurality of objects, the method comprising steps of:

receiving a snapshot time identifying a point in time in a history of the file system; and

identifying at least one object available from the file system at the snapshot time based on one or more of a creation timestamp and an invisible_after timestamp for the at least one object, wherein the creation timestamp is associated with a time the at least one object is created in the file system and the invisible_after timestamp is associated with a time the at least one object is made unavailable from the file system.

2. The method of claim 1, further comprising transmitting object information to a client of the file system, the object information including information about the at least one identified object.

3. The method of claim 1, further comprising steps of:

generating a creation timestamp for each of a plurality of objects in the file system; and

generating an invisible_after timestamp for each of the plurality of objects in the file system.

4. The method of claim 3, wherein the step of identifying at least one object further comprises steps of:

determining whether a creation timestamp for the at least one object is approximately before the snapshot time;

determining whether an invisible_after timestamp for the at least one object is approximately after the snapshot time; and

identifying the at least one object as available in response to the creation timestamp being approximately before the snapshot time and the invisible_after timestamp for the at least one object being approximately after the snapshot time.

5. The method of claim 4, further comprising repeating the steps of claim 4 for each object in the file system to identify whether each object is available at the snapshot time.

6. The method of claim 2, wherein the step of transmitting further comprises transmitting the object information to a file system utility on the client.

7. The method of claim 6, further comprising displaying the object information using the file system utility, the displayed object information including information regarding any object available from the file system at the snapshot time.

8. The method of claim 1, wherein the file system is an archival system operable to store multiple versions of a file.

9. The method of claim 3, wherein the file system is a semantic, archival, file system storing a semantic catalogue including an entry for each object in the file system, and the step of generating a creation timestamp further comprises storing the creation timestamp for each object in an associated entry in the semantic catalogue;

and

the step of generating an invisible_after timestamp further comprises storing the invisible_after timestamp for each object in an associated entry in the semantic catalogue.

10. A file system operable to store a plurality of objects comprising:

means for receiving a snapshot time; and

means for identifying at least one object available from the file system at the snapshot time based on one or more of a creation timestamp and an invisible_after timestamp for the at least one object, wherein the creation timestamp is associated with a time the at least one object is created in the file system and the invisible_after timestamp is associated with a time the at least one object is made unavailable from the file system.

11. The file system of claim 10, further comprising means for transmitting object information to a client of the file system, the object information including information about the at least one identified object.

12. The file system of claim 10, further comprising:

means for generating a creation timestamp for each of a plurality of objects in the file system; and

means for generating an invisible_after timestamp for each of the plurality of objects in the file system.

13. The file system of claim 12, wherein the means for identifying at least one object further comprises:

means for determining whether a creation timestamp for the at least one object is approximately before the snapshot time;

means determining whether an invisible_after timestamp for the at least one object is approximately after the snapshot time; and

means for identifying the object as available in response to the creation timestamp being approximately before the snapshot time and the invisible_after timestamp for the object being approximately after the snapshot time.

14. The file system of claim 11, wherein the means for transmitting further comprises transmitting the object information to a file system utility on the client.

15. The file system of claim 14, wherein the client further comprises means for displaying the object information using the file system utility, the displayed object information including information regarding any object available from the file system at the snapshot time.

16. The file system of claim 12, further comprising a semantic, archival, file system storing a semantic catalogue including an entry for each object in the file system.

17. The file system of claim 16, wherein the means for generating a creation timestamp further comprises means for storing the creation timestamp for each object in an associated entry in the semantic catalogue;

and

the means for generating an invisible_after timestamp further comprises means for storing the invisible_after timestamp for each object in an associated entry in the semantic catalogue.

18. An archival file system comprising:

a file system connected to at least one client via a network, wherein the file system stores a first timestamp and a second time stamp for each of a plurality of objects in the file system; and

the file system is operable to generate a snapshot of the file system using the timestamps for each of the plurality of objects.

19. The archival file system of claim 18, wherein the file system is on a P2P platform.

20. The archival file system of claim 18, further comprising a semantic catalogue storing semantic information for the plurality of objects.