Operating System and File System Independent Incremental Data Backup

• US 20110113012A1
• Filed: 11/06/2009
• Published: 05/12/2011
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: Dropbox, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Smith, Mark Andrew, Gruhl, Daniel, Pieper, Jan H.
• Granted Patent: US 8,595,188 B2
• Time in Patent Office: Days
• US Class Current: 707/646
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 2201/815 Virtual middleware or OS functionality using virtual machines to implement generic software techniques for error detection or fault masking G06F11/1484

Abstract

Embodiments of the invention relate to creating an operating system and file system independent incremental data backup. A first data backup of a source system and second version of the data on the source system is received. A second data backup of the second version of the data is created by determining differences between the first data backup and the second version of the data. Each portion of the second version of the data that is the same as a portion of the first data backup is referenced in the second data backup. Each portion of the second version of the data that is different than all portions of the first data backup is included in the second data backup. The second data backup is appended to the first data backup to create an incremental data backup.

Claims

1. A method for creating an operating system and file system independent incremental data backup, comprising:

receiving a first data backup of a source system;

receiving a second version of data of the source system; and

creating a second data backup of the second version of the data, comprising;

determining differences between the first data backup and the second version of the data,

for a portion at a first position of the second version of the data that is the same as a portion of the first data backup, referencing the portion of the first data backup in the second data backup, and

for a portion at a first position of the second version of the data that is different than all portions of the first data backup, including the portion of the second version of the data in the second data backup.

2. The method of claim 1, further comprising:

creating an incremental data backup, wherein creating an incremental data backup up comprises appending the second data backup to the first data backup.

3. The method of claim 1, wherein determining the differences between the first data backup and the second version of the data comprises comparing a byte stream of the first data backup to a byte stream of the second version of the data.

4. The method of claim 1, wherein determining the differences between the first data backup and the second version of the data comprises comparing a signature for a potion of the second version of data to signatures for a plurality of portions of the first data backup.

5. The method of claim 2, wherein creating the second data backup further comprises creating reconstruction metadata for assembling the incremental data backup into a replication of the second version of the data.

6. The method of claim 4, wherein for each new data backup of the data, a data backup is made for a version of data and appended to the first data backup to create an incremental data backup, further wherein the signatures for comparison are signatures for the current version of the data and signatures for a most recently backed up version of the data.

7. The method of claim 4, wherein:

the signatures for the portions of the first data backup and the second version of the data are hashes,

the hashes for the portions of the first data backup are stored in a first hash table, and

the hashes for the portions of the second version of the data are stored in a hash table selected from the group consisting of the first hash table, and a second hash table.

8. The method of claim 4, further comprising:

creating the first data backup of a first version of the data, wherein creating the first data backup of the first version of the data comprises;

comparing hashes of portions of the first version of the data to hashes of portions of previously stored data,

for portions of the first version of the data that have a same hash as portions of the previously stored data, referencing the portions of the first version of the data in the first data backup, and

for portions of the first version of the data that have a different hash than portions of the previously stored data, storing the portions of the first version of the data in the first data backup.

9. The method of claim 8, wherein the portions of the first version of the data and the portions of the second version of the data are partitioned using a chunking method selected from the group consisting of content-agnostic chunking, content-aware chunking, and fixed-size chunking.

10. A computer program product for creating an operating system and file system independent incremental data backup, comprising:

a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising;

computer readable program code configured to receive a first data backup of a source system,

computer readable program code configured to receive a second version of data of the source system, and

computer readable program code configured to create a second data backup of the second version of the data, comprising;

determine differences between the first data backup and the second version of the data,

for a portion at a first position of the second version of the data that is the same as a portion of the first data backup, reference the portion of the first data backup in the second data backup, and

for a portion at a first position of the second version of the data that is different than all portions of the first data backup, include the portion of the second version of the data in the second data backup.

11. The computer program product of claim 10, further comprising:

computer readable program code configured to create an incremental data backup, wherein creating the incremental data backup comprises appending the second data backup to the first data backup.

12. The computer program product of claim 10, wherein determining the differences between the first data backup and the second version of the data comprises comparing a signature for a potion of the second version of data to signatures for a plurality of portions of the first data backup.

13. The system of claim 11, wherein creating the second data backup further comprises creating reconstruction metadata for assembling the incremental data backup into a replication of the second version of the data.

14. The computer program product of claim 12, wherein:

the signatures for the portions of the first data backup and the second version of the data are hashes,

the hashes for the portions of the first data backup are stored in a first hash table, and

the hashes for the portions of the second version of the data are stored in a hash table selected from the group consisting of the first hash table, and a second hash table.

15. The computer program product of claim 12, further comprising:

computer readable program code configured to create the first data backup of a first version of the data, wherein creating the first data backup of the first version of the data comprises;

comparing hashes of portions of the first version of the data to hashes of portions of previously stored data,

for portions of the first version of the data that have a same hash as portions of the previously stored data, referencing the portions of the first version of the data in the first data backup, and

for portions of the first version of the data that have a different hash than portions of the previously stored data, storing the portions of the first version of the data in the first data backup.

16. A system for creating an operating system and file system independent incremental data backup, comprising:

a storage subsystem coupled to a source system;

a receiving module coupled to the storage subsystem and configured to;

receive a first data backup of a source system, and

receive a second version of data of the source system from the storage subsystem; and

a creation module coupled to the receiving module and configured to create a second data backup of the second version of the data, comprising;

determining differences between the first data backup and the second version of the data,

for a portion at a first position of the second version of the data that is the same as a portion of the first data backup, referencing the portion of the first data backup in the second data backup, and

for a portion at a first position of the second version of the data that is different than all portions of the first data backup, including the portion of the second version of the data in the second data backup.

17. The system of claim 16, further comprising:

creating an incremental data backup, wherein creating an incremental data backup up comprises appending the second data backup to the first data backup.

18. The system of claim 16, wherein determining the differences between the first data backup and the second version of the data comprises comparing a signature for a potion of the second version of data to signatures for a plurality of portions of the first data backup.

19. The system of claim 17, wherein creating the second data backup further comprises creating reconstruction metadata for assembling the incremental data backup into a replication of the second version of the data.

20. The system of claim 18, wherein the creation module is further configured to create the first data backup of the first version of the data, further wherein creating the first data backup of the first version of the data comprises:

comparing hashes of portions of the first version of the data to hashes of portions of previously stored data,

for portions of the first version of the data that have a same hash as portions of the previously stored data, referencing the portions of the first version of the data in the first data backup, and

for portions of the first version of the data that have a different hash than portions of the previously stored data, storing the portions of the first version of the data in the first data backup.