Host-independent incremental backup method, apparatus, and system

• US 20040243775A1
• Filed: 06/02/2003
• Published: 12/02/2004
• Est. Priority Date: 06/02/2003
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: McKean, Brian Dennis, Coulter, Robert Clyde
• Granted Patent: US 7,069,402 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

Block-level operations are tracked within a storage subsystem. Metadata corresponding to the block-level operations are collected within the storage subsystem between snapshot (i.e., backup) instances. The collected metadata are referenced to ensure that only overwritten data blocks are copied to the backup device. The present invention leverages the capabilities of flashcopy operations, frees the host from costly housekeeping tasks, and facilitates efficient backup operations independent of a host or filesystem.

Claims

1. A storage controller for controlling storage devices and conducting block-level incremental backups within a storage subsystem in a host-independent manner, the storage controller configured to:

track block-level operations;

receive a first snapshot command at a first time instance;

receive a second snapshot command at a second time instance; and

transfer data corresponding to blocks overwritten between the first time instance and one second time instance to a backup device.

2. The storage controller of claim 1, further configured to collect metadata describing the block-level operations.

3. The storage controller of claim 2, wherein the metadata is stored within the storage subsystem.

4. The storage controller of claim 1, further configured to store the metadata on the backup device.

5. The storage controller of claim 1, further configured to track block-level operations by initiating a flashcopy command.

6. The storage controller of claim 1, wherein the first snapshot command corresponds to a baseline backup.

7. The storage controller of claim 1, wherein the second snapshot command corresponds to an incremental backup.

8. The storage controller of claim 1, wherein the first and second snapshot commands are received from a host.

9. The storage controller of claim 1, wherein the first and second snapshot commands are scheduled events.

10. The storage controller of claim 1, wherein the backup device is selected from a tape device, a magnetic device, an optical device, a solid state device, a tape library, and a second storage subsystem.

11. A storage subsystem for storing data and conducting block-level incremental backups in a host-independent manner, the storage subsystem comprising:

a plurality of storage devices; and

at least one controller configured to track block-level operations, receive a first snapshot command at a first time instance, receive a second snapshot command at a second time instance, and transfer data corresponding to blocks overwritten between the first time instance and the second time instance to a backup device.

12. A system for archiving data in a host-independent manner, the system comprising:

at least one host configured to process data and request storage services;

a plurality of storage devices; and

at least one controller configured to track block-level operations, receive a first snapshot command at a first time instance, receive a second snapshot command at a second time instance, and transfer data corresponding to blocks overwritten between the first time instance and the second time instance to a backup device.

13. A storage area network for storing data, the storage area network comprising:

a plurality of storage subsystems;

a network configured to interconnect the plurality of storage subsystems; and

at least one storage subsystem of the plurality of storage subsystems comprising at least one controller configured to track block-level operations, receive a first snapshot command at a first time instance, receive a second snapshot command at a second time instance, and transfer data corresponding to blocks overwritten between the first time instance and the second time instance to a backup device.

14. A computer readable storage medium comprising computer readable program code for conducting incremental snapshots within a storage subsystem in a host-independent manner, the program code configured to:

track block-level operations;

receive a first snapshot command at a first time instance;

receive a second snapshot command at a second time instance; and

transfer data corresponding to blocks overwritten between the first time instance and the second time instance to a backup device.

15. The computer readable storage medium of claim 14, wherein the program code is further configured to collect metadata describing the block-level operations.

16. An apparatus for conducting block-level incremental backups in a host-independent manner within a storage subsystem, the method comprising:

means for tracking block-level operations within the storage subsystem;

means for receiving a first snapshot command at a first time instance;

means for receiving a second snapshot command at a second time instance; and

means for transferring data corresponding to blocks overwritten between the first and second time instance to a backup device.

17. A method for conducting block-level incremental backups in a host-independent manner within a storage subsystem, the method comprising:

tracking block-level operations within the storage subsystem;

receiving a first snapshot command at a first time instance;

receiving a second snapshot command at a second time instance; and

transferring data corresponding to blocks overwritten between the first and second time instance to a backup device.

18. The method of claim 17, further comprising collecting metadata describing the block-level operations.

19. The method of claim 18, wherein the metadata is stored within the storage subsystem.

20. The method of claim 17, wherein tracking block-level operations is initiated with a flashcopy command.

21. The method of claim 17, wherein the first snapshot command corresponds to a baseline backup.

22. The method of claim 17, wherein the second snapshot command corresponds to an incremental backup.

23. The method of claim 17, wherein the first and second snapshot commands are received from a host.

24. The method of claim 17, wherein the first and second snapshot commands are scheduled events conducted within the storage subsystem.

25. The method of claim 17, wherein the backup device is selected from a tape device, a magnetic device, an optical device, a solid state device, a tape library, and a second storage subsystem.