Recovering a file system to any point-in-time in the past with guaranteed structure, content consistency and integrity

• US 8,352,523 B1
• Filed: 09/23/2011
• Issued: 01/08/2013
• Est. Priority Date: 03/30/2007
• Status: Active Grant

• Current Assignee: Quest Software, Inc.
• Original Assignee: Quest Software, Inc.
• Inventors: Sim-Tang, Siew Yong
• Primary Examiner(s): VO, TRUONG V
• Application Number:
  US13/242,916
• Time in Patent Office: 473 Days
• Field of Search: 707/800, 707/829
• US Class Current: 707/829
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• 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 16/1873 Versioning file systems, temporal file systems, e.g. file system supporting different historic versions of files

Abstract

A data management system (DMS) includes a continuous real-time object store that captures all real-time activities, with associated object metadata information. The DMS is capable of reintroducing any point-in-time view of data ranging from a granular object to an entire file system. A set of algorithms (for creation of a file or directory, modification of a file or directory, deletion of a file or directory, and relocation/renaming of a file or directory) are used to generate and maintain a file system history in the DMS and to ensure that a latest version of a directory always refers to a latest version of its children until the directory changed. Any point-in-time recovery is implemented using the file system history in one of various ways to provide strong individual file integrity, exact point-in-time crash consistency, and/or recovery of last version of all files in the file system.

Claims

1. A machine-implemented data management method, comprising:

receiving application specific data transactions;

storing in a data store a real-time history of at least a portion of a data source as an object-oriented logical representation based at least in part on the application specific data transactions;

relocating a directory object in response to a relocation event, wherein the directory object has a first version at a first location in the object-oriented logical representation that comprises a plurality of children objects having one or more binary and delta pages associated therewith,

wherein the relocation event relocates the directory object to a second location in the object-oriented logical representation by creating a second version of the directory object at the second location,

wherein the second version of the directory object at the second location is linked with the first version of the directory object at the first location across at least a portion of a lifetime of the directory object wherever the directory object is relocated, and

wherein the second version of the directory object is further linked to the plurality of children objects associated with the first version of the directory object; and

using the object-oriented logical representation for a point-in-time recovery of the at least a portion of the data source.

2. The method of claim 1 further comprising receiving from the at least a portion of the data source an application-aware data stream formed from captured application data transactions, the application-aware data stream representing a continuous real-time history of the at least a portion of the data source and including events, metadata, and data changes.

3. The method of claim 1 wherein the point-in-time recovery of the at least a portion of the data source has a recovery consistency characteristic.

4. The method of claim 3 wherein the recovery consistency characteristic is selected from the group consisting of strong individual file integrity, exact point-in-time crash consistency, and last version of all files.

5. The method of claim 1 further comprising relocating the directory object based on an object path.

6. The method of claim 1 further comprising relocating based on a combination of object path and directory object instance.

7. The method of claim 1 wherein the object-oriented logical representation provides an n-dimensional representation of the data source at a given point in time.

8. The method of claim 1 wherein the children objects comprise at least one a file object.

9. The method of claim 1 wherein relocating includes moving the directory object from a first directory to a second directory, where the first directory is distinct from the second directory.

10. The method of claim 1 wherein relocating includes moving the directory object within a directory.

11. A system for data recovery comprising:

computer hardware including at least one computer processor; and

computer-readable storage comprising computer-executable instructions that, when executed by the computer processor, cause the computer hardware to perform operations defined by the computer-executable instructions, the computer-executable instructions configured to;

receive application specific data transactions;

store in a data store a real-time history of at least a portion of a data source as an object-oriented logical representation based at least in part on the application specific data transactions;

relocate a directory object associated with the data source in response to a relocation event, wherein the directory object has a first version at a first location in the object-oriented logical representation, that comprises a plurality of children objects having one or more binary and delta pages associated therewith,

wherein the relocation event relocates the directory object to a second location in the object-oriented logical representation by creating a second version of the directory object at the second location,

wherein the second version of the directory object at the second location is linked with the first version of the directory object at the first location across at least a portion of a lifetime of the directory object wherever the directory object is relocated, and

wherein the second version of the directory object is further linked to the plurality of children objects associated with the first version of the directory object; and

use the object-oriented logical representation for a point-in-time recovery of the at least a portion of the data source.

12. The system of claim 11 wherein the computer-executable instructions are further configured to receive from the at least a portion of the data source an application-aware data stream formed from captured application data transactions, the application-aware data stream representing a continuous real-time history of the at least a portion of the data source and including events, metadata, and data changes.

13. The system of claim 11 wherein the computer-executable instructions are further configured to relocate the directory object based on an object path.

14. The system of claim 11 wherein relocating the directory object includes renaming the directory object.

15. The system of claim 11 wherein the computer-executable instructions are further configured to relocate based on a combination of object path and directory object instance.

16. The system of claim 11 wherein the children objects comprise at least one file object.

17. The system of claim 11 wherein the point-in-time recovery of the at least a portion of the data source has a recovery consistency characteristic.

18. The system of claim 17 wherein the recovery consistency characteristic is selected from the group consisting of strong individual file integrity, exact point-in-time crash consistency, and last version of all files.