File system backup using change journal

Patent metadata

Field	Value
Publication number	US-9824091-B2
Application number	US-95940110-A
Country	US
Kind code	B2
Filing date	Dec 3, 2010
Priority date	Dec 3, 2010
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

Aspects of the subject matter described herein relate to backups and change journals. In aspects, a change journal is read to determine changes that have occurred to objects of a file system. From these changes a data structure is created to capture path information and collect changes for each object. Where the data structure is insufficient to identify a complete path, the live file system is consulted. After the data structure is complete, a data protection engine uses the data structure to update a catalog at least to provide the capability to view the namespace of the protected objects at one or more times covered by the catalog.

First claim

What is claimed is:

1. A method performed on a computing device, the method comprising:
creating, based on records of a change journal, a plurality of tree data structure fragments that are not connected together in a single tree data structure that includes a root node, where each of the records corresponds to a file system object that has been changed in a file system;
building a data structure from the single tree structure using the plurality of tree data structure fragments combined with path information obtained from a live instance of the file system, where the built single tree structure includes the root node;
updating a catalog of file system objects in a protected namespace using the data structure; and
creating backup sets of changed file system objects in the protected namespace from the updated catalog.

2. The method of claim 1 , where each of the records includes name information of a file system object and a parent thereof.

3. The method of claim 1 , where each of the records is associated with a number that indicates a sequence of the each of the records in the change journal.

4. The method of claim 3 , further comprising determining if a file system object reflected in the built single tree structure changed after the creating, the determining based on comparing a sequence number of the file system object with a highest sequence number of the change journal.

5. The method of claim 1 further comprising updating a catalog based on the built single tree structure, where the updated catalog is configured for providing a view of a namespace of any backup set covered by the updated catalog.

6. The method of claim 1 further comprising creating, based on the obtained path information and in response to a parent node corresponding to a parent object of a changed file system object not existing in the created tree data structure fragments, the parent node and connecting the created parent node into the tree data structure.

7. The method of claim 1 further comprising backing up, according to the built tree data structure, at least a portion of the changed file system objects.

8. The method of claim 5 where the updating the catalog comprises updating a timestamp of the catalog, where the updated timestamp indicates creation of a backup set.

9. At least one computer-readable storage media not consisting of propagated signals storing computer-executable instructions that, when executed by a computing device, cause the computing device to perform actions comprising:
creating, based on records of a change journal, a plurality of tree data structure fragments that are not connected together in a single tree data structure that includes a root node, where each of the records corresponds to a file system object that has been changed in a file system;
building a data structure from the single tree structure from the plurality of tree data structure fragments combined with path information obtained from a live instance of the file system, where the built single tree structure includes the root node;
updating a catalog of file system objects in a protected namespace using the data structure; and
creating backup sets of changed file system objects from the updated catalog.

10. The at least one computer storage media of claim 9 , where each of the records includes name information of a file system object and a parent thereof.

11. The at least one computer storage media of claim 9 , where each of the records is associated with a number that indicates a sequence of the each of the records in the change journal.

12. The at least one computer storage media of claim 9 , the actions further comprising determining if a file system object reflected in the built single tree structure changed after the creating, the determining based on comparing a sequence number of the file system object with a highest sequence number of the change journal.

13. The at least one computer storage media of claim 9 , the actions further comprising updating a catalog based on the built single tree structure, where the updated catalog is configured for providing a view of a namespace of any backup set covered by the updated catalog.

14. The at least one computer storage media of claim 13 , the action further comprising creating, based on the obtained path information and in response to a parent node corresponding to a parent object of a changed file system object not existing in the created tree data structure fragments, the parent node and connecting the created parent node into the tree data structure.

15. The at least one computer storage media of claim 9 , the actions further comprising backing up, according to the built tree data structure, at least a portion of the changed file system objects.

16. A system, comprising:
one or more processors; and
one or more computer-readable storage media not consisting of propagated signals storing computer-executable instructions that, when executed by the one or more processors, cause the system to perform actions comprising
creating, based on records of a change journal, a plurality of tree data structure fragments that are not connected together in a single tree data structure that includes a root node, where each of the records corresponds to a file system object that has been changed in a file system;
building a data structure from the single tree structure from the plurality of tree data structure fragments combined with path information obtained from a live instance of the file system, where the built single tree structure includes the root node,
updating a catalog of file system objects in a protected namespace using the data structure; and
creating backup sets of changed file system objects from the updated catalog.

17. The system of claim 16 , the actions further comprising updating a catalog based on the built single tree structure, where the updated catalog is configured for providing a view of a namespace of any backup set covered by the updated catalog.

18. The system of claim 17 where the updating the catalog comprises updating a timestamp of the catalog, where the updated timestamp indicates creation of a backup set.

19. The system of claim 16 , the actions further comprising backing up, according to the built tree data structure, at least a portion of the changed file system objects.

20. The system of claim 16 , where each of the records includes name information of a file system object and a parent thereof.

Assignees

• Boehm Branton Nicolas
• Doshi Apurva Ashwin
• Pang Juan-Lee
• Lyakhovitskiy Grigory Borisovich
• Havewala Sarosh Cyrus
• Microsoft Technology Licensing Llc

Inventors

• Boehm Branton Nicolas
• Doshi Apurva Ashwin
• Pang Juan-Lee
• Lyakhovitskiy Grigory Borisovich
• Havewala Sarosh Cyrus

Classifications

• G06F16/1815

  Journaling file systems · CPC title

• G06F2201/84

  Using snapshots, i.e. a logical point-in-time copy of the data · CPC title

• G06F11/1451

  by selection of backup contents · CPC title

• G06F16/2358

  Change logging, detection, and notification (replication G06F16/27) · CPC title

• G06F16/113

  Details of archiving (lifecycle management in storage systems G06F3/0649; point-in-time backing up or restoration of persistent data G06F11/1446) · CPC title