Method and system for versioned file system using structured data representations

• US 20100191774A1
• Filed: 06/11/2009
• Published: 07/29/2010
• Est. Priority Date: 01/23/2009
• Status: Active Grant

• Current Assignee: Nasuni Corporation
• Original Assignee: Nasuni Corporation
• Inventors: Rodriguez, Andres, Mason, Robert S. JR.
• Granted Patent: US 8,566,362 B2
• Time in Patent Office: Days
• US Class Current: 707/797
• CPC Class Codes: G06F 11/1446 Point-in-time backing up or restoration of persistent data
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: G06F 16/183 Provision of network file services by network file servers, e.g. by using NFS, CIFS network file access protocols H04L67/1097
• CPC Class Codes: G06F 16/1873 Versioning file systems, temporal file systems, e.g. file system supporting different historic versions of files
• CPC Class Codes: G06F 16/9027 Trees
• CPC Class Codes: G06F 2201/805 Real-time
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

A versioned file system comprises a set of structured data representations, such as XML. In a representative embodiment, at a first time, the interface creates and exports to the data store a first structured data representation corresponding to a first version of the local file system. The first structured data representation is an XML tree having a root element, one or more directory elements associated with the root element, and one or more file elements associated with a given directory element. Upon a change within the file system (e.g., file creation, file deletion, file modification, directory creation, directory deletion and directory modification), the interface creates and exports a second structured data representation corresponding to a second version of the file system. The second structured data representation differs from the first structured data representation up to and including the root element of the second structured data representation. The interface continues to generate and export the structured data representations to the data store, preferably at given “snapshot” times when changes within the file system have occurred. The data store preferably comprises one or more cloud storage service providers. As necessary, a given structured data representation is then used to retrieve an associated version of the file system. In this manner, the versioned file system only requires write-once behavior from the data store to preserve its complete state at any point-in-time.

Claims

1. A computer-readable medium having stored thereon instructions that, when executed by a processor, perform a method associated with a file system, the method comprising:

at a first time, creating and exporting a first structured data representation corresponding to a first version of the file system, wherein the first structured data representation is a tree having a root element, one or more directory elements associated with the root element, and one or more file elements associated with a given directory element; and

upon a change within the file system, creating and exporting a second structured data representation corresponding to a second version of the file system, the second structured data representation differing from the first structured data representation up to and including the root element of the second structured data representation.

2. The medium as described in claim 1 wherein the first and second structured data representations are exported to a data store.

3. The medium as described in claim 2 wherein the data store is a write-once data store.

4. The medium as described in claim 1 wherein the structured data representation is an XML representation.

5. The medium as described in claim 4 wherein the root element is a data array that includes a manifest associated with each of the first and second versions of the file system as represented by the first and second structured data representations.

6. The medium as described in claim 4 wherein a directory element is a data array that includes a manifest that identifies one or more directory chunks that comprise a directory within the file system.

7. The medium as described in claim 6 wherein a directory chunk is a data array that includes one or more directory entry elements each associated with a subdirectory in the file system.

8. The medium as described in claim 4 wherein a file element is a data array that includes a manifest that identifies one or more file chunks that comprise a file within the file system.

9. The medium as described in claim 1 further including applying a data transformation to the first and second structured data representations prior to the exporting step.

10. The medium as described in claim 1 wherein the second structured data representation is exported at a given second time.

11. The medium as described in claim 1 wherein the change within the file system is one of:

a file creation, file deletion, file modification, directory creation, directory deletion and directory modification.

12. The medium as described in claim 1 wherein the second structured data representation differs from the first structured data representation in one or more parent elements with respect to the structured data element in which the change within the file system occurred.

22. The medium as described in claim 9 wherein the data transformation is one of:

encryption, compression and duplicate elimination.

13. A computer-readable medium having stored thereon instructions that, when executed by a processor, perform a method associated with a file system, the method comprising:

upon a given occurrence within the file system, creating and exporting a structured data representation corresponding to a current version of the file system, wherein the structured data representation is a tree having a root element, one or more directory elements associated with the root element, and one or more file elements associated with a directory element, and wherein a current structured data representation differs from a most recent structured data representation up to and including the root element of the current structured data representation; and

using a structured data representation to retrieve an associated version of the file system.

14. The medium as described in claim 13 wherein the structured data representation is used to retrieve the associated version of the file system at a given point-in-time.

15. The medium as described in claim 13 wherein each structured data representation is exported to a data store.

16. The medium as described in claim 13 wherein the structured data representation is an XML representation.

17. The medium as described in claim 13 further including applying one or more data transformations to the structured data representation prior to the exporting step.

18. The medium as described in claim 13 wherein the given occurrence is one of:

a file creation, file deletion, file modification, directory creation, directory deletion and directory modification.

19. Apparatus, comprising:

a processor;

a data store holding computer instructions that, when executed by the processor, perform a method associated with a file system, the method comprising;

at a first time, creating and exporting a first structured data representation corresponding to a first version of the file system, wherein the first structured data representation is a tree having a root element, one or more directory elements associated with the root element, and one or more file elements associated with a given directory element; and

upon a change within the file system, creating and exporting a second structured data representation corresponding to a second version of the file system, the second structured data representation differing from the first structured data representation up to and including the root element of the second structured data representation.

20. Apparatus, comprising:

a processor;

a data store holding computer instructions that, when executed by the processor, perform a method associated with a file system, the method comprising;

upon a given occurrence within the file system, creating and exporting a structured data representation corresponding to a current version of the file system, wherein the structured data representation is a tree having a root element, one or more directory elements associated with the root element, and one or more file elements associated with a directory element, and wherein a current structured data representation differs from a most recent structured data representation up to and including the root element of the current structured data representation; and

using a structured data representation to retrieve an associated version of the file system.

21. A method of storing data in a data store as a file system, comprising:

at a first time, creating and exporting to the data store a first structured data representation corresponding to a first version of the file system, wherein the first structured data representation is a tree having a root element, one or more directory elements associated with the root element, and one or more file elements associated with a given directory element; and

upon a given occurrence, creating and exporting to the data store a second structured data representation corresponding to a second version of the file system, the second structured data representation differing from the first structured data representation up to and including the root element of the second structured data representation;

wherein the first and second structured data representations comprise a versioned file system for the data store.