Method and apparatus for storage backup

• US 20070027937A1
• Filed: 01/13/2006
• Published: 02/01/2007
• Est. Priority Date: 05/21/2004
• Status: Active Grant

• Current Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Original Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Inventors: Ball, Stephen, Yang, Frank, Rivet, Jean-Francois, Kuo, Chin, McGrattan, Emma, Moucaddem, Sami
• Granted Patent: US 7,814,056 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 2201/80 Database-specific techniques
• CPC Class Codes: G06F 2201/83 the solution involving signatures
• CPC Class Codes: G06F 2201/835 Timestamp

Abstract

Methods and apparatuses for backing up data to a database are provided. A specified data set to be backed up is broken down into a plurality of data blocks, each data block is associated with a data block digest, and the data blocks and associated data block digests are stored in the database. When one or more data blocks are subsequently changed, an update to the backup may be performed by adding to the backup data only the data blocks that have changed since the initial backup. Methods and apparatuses for restoring backup data from a database are also provided. Timestamp information associated with the data blocks in the database is used to select the data blocks to be restored.

Claims

1. A method for backing up data, comprising:

breaking down a specified data set to be backed up into a plurality of data blocks;

generating for each data block a corresponding data block digest and associating the data block digest with the data block; and

storing the data block and the associated generated data block digest in a database.

2. The method of claim 1, further comprising refreshing backup of the specified data set after the data set has been backed up.

3. The method of claim 2, wherein the refreshing backup of the specified data set includes determining a new data block digest of a selected data block in the specified data set to be refreshed, comparing the new data block digest of the selected data block to the stored data block digest of the associated data block in the database which corresponds to the selected data block, and backing up the selected data block and new data block digest in the database if the new data block digest of the selected data block does not equal the stored data block digest of the associated data block in the database.

4. The method of claim 3, wherein if the selected data block in the specified data set is backed up in the database, the selected data block replaces the associated data block in the database as a current version of the data block.

5. The method of claim 1, wherein the data blocks have a fixed size per object set.

6. The method of claim 1, wherein each data block stored in the database is stored with associated timestamp information.

7. The method of claim 1, wherein the data to be backed up is pre-selected by a user and arranged into an object set.

8. The method of claim 7, wherein the object set is referenced by a set identifier.

9. The method of claim 7, wherein the object set comprises a plurality of data objects.

10. The method of claim 9, wherein each data object has an associated object identifier and object name.

11. The method of claim 9, wherein an object instance of a data object includes an object identifier, timestamp and attribute information.

12. The method of claim 11, wherein the attribute information of the object instance is stored in the database.

13. The method of claim 11, wherein the object identifier and the timestamp information of the object instance are stored as metadata in a database catalog.

14. The method of claim 9, wherein an object map is generated for a data object, and the object map includes object identifier, timestamp, data block number, block identifier and data block digest information.

15. The method of claim 14, wherein the data block digest information and the data block number information are stored in the database.

16. The method of claim 14, wherein the object identifier information, timestamp information and block identifier information are stored as metadata in a database catalog.

17. A computer system comprising:

a processor; and

a program storage device readable by the computer system and tangibly embodying a program of instructions executable by the processor to perform the method claimed in claim 1.

18. A program storage device readable by a machine and tangibly embodying a program of instructions executable by the machine to perform the method claimed in claim 1.

19. A computer data signal transmitted in one or more segments in a transmission medium which embodies instructions executable by a computer to perform the method claimed in claim 1.

20. The method of claim 1, further comprising:

comparing the generated data block digest for a selected data block in the specified data set to be backed up on the one hand, and on the other hand, data block digests associated of backed up data blocks stored in the database to determine whether the selected data block is already backed up, wherein the selected data block and the generated data block digest are stored in the database if the generated data block digest is not equal to any of the data block digests of the backed up data blocks stored in the database.

21. The method of claim 14, further comprising deleting a data object when requested, wherein the data object is flagged as deleted in a database catalog, and data blocks and the object map corresponding to the data object remain in the database until requested to be permanently deleted.

22. The method of claim 1, further comprising updating a backup of the specified data set after the data set has been backed up.

23. A method for restoring backup data from a database, said backup data being stored in the database as a plurality of data blocks, the method comprising:

receiving specification of a time to which data restoration is desired;

comparing the specified time to timestamp information stored for each data block of the backup data in the database; and

retrieving a selected data block of the backup data, if the selected data block has an associated timestamp at or earlier than the specified time and no other data blocks of the backup data which correspond to the selected data block have more contemporaneous timestamps between the specified time and the associated timestamp of the selected data block.

25. The method of claim 23, wherein the backup data is retrieved from the database.

26. The method of claim 23, further comprising backing up the restored backup data to a secondary backup medium.

27. A computer system comprising:

a processor; and

a program storage device readable by the computer system and tangibly embodying a program of instructions executable by the processor to perform the method claims in claim 23.

28. A program storage device readable by a machine and tangibly embodying a program of instructions executable by the machine to perform the method claimed in claim 23.

29. A computer data signal transmitted in one or more segments in a transmission medium which embodies instructions executable by a computer to perform the method claimed in claim 23.

24. The method of 23, wherein the timestamp information is retrieved from a database catalog.

30. A method for restoring backup data from a database, comprising:

retrieving timestamp information for a group of corresponding data blocks in the backup data from a database catalog;

comparing the timestamp information for the data blocks in the group;

selecting a data block in the group having the most recent timestamp as compared to the other corresponding data blocks in the group; and

restoring the data block having the most recent timestamp.

31. The method of claim 30, further comprising, grouping each of the data blocks with the most recent timestamp by object set, and ordering each data block within each object set by block number.

32. A computer system comprising:

a processor; and

a program storage device readable by the computer system and tangibly embodying a program of instructions executable by the processor to perform the method claims in claim 30.

33. A program storage device readable by a machine and tangibly embodying a program of instructions executable by the machine to perform the method claimed in claim 30.

34. A computer data signal transmitted in one or more segments in a transmission medium which embodies instructions executable by a computer to perform the method claimed in claim 30.

35. An apparatus for backing up data to a database comprising:

means for breaking down a specified data set to be backed up into a plurality of data blocks;

means for generating for each data block a corresponding data block digest and associating the data block digest with the data block; and

means for storing the data block and the associated generated data block digest in a database.

36. The apparatus of claim 35, further comprising:

an object system for storing data to be backed up;

an object system agent for generating and assigning data block identifiers;

a software interface for managing operations related to the backup and retrieval of the data;

a database catalog for storing metadata relating to the data to be backed up;

a database server for providing an interface to the database catalog;

a database for storing the data to be backed up; and

a media server for implementing attached storage devices/media.

37. An apparatus for restoring backup data from a database, said backup data being stored in the database as a plurality of data blocks, the system comprising:

means for receiving specification of a time to which data restoration is desired;

means for comparing the specified time to timestamp information stored for each data block of the backup data in the database; and

means for retrieving a selected data block of the backup data, if the selected data block has an associated timestamp at or earlier than the specified time and no other data blocks of the backup data which correspond to the selected data block have more contemporaneous timestamps between the specified time and the associated timestamp of the selected data block.

38. An apparatus for restoring backup data from a database, the system comprising:

means for retrieving timestamp information for a group of corresponding data blocks in the backup data from a database catalog;

means for comparing the timestamp information for the data blocks in the group;

means for selecting a data block in the group having the most recent timestamp as compared to the other corresponding data blocks in the group; and

means for restoring the data block having the most recent timestamp.