Method and apparatus for backup and recovery using storage based journaling

• US 7,243,197 B2
• Filed: 04/20/2006
• Issued: 07/10/2007
• Est. Priority Date: 06/26/2003
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamagami, Kenji
• Primary Examiner(s): Bataille; Pierre
• Assistant Examiner(s): PATEL, HETUL B
• Application Number:
  US11/408,831
• Publication Number:
  US 20060190692A1
• Time in Patent Office: 446 Days
• Field of Search: 711/159, 711/161, 711/162, 707/200, 707/201, 707/202, 707/203, 707/204, 707/205, 714/6, 714/7
• US Class Current: 711/161
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 11/3485 for I/O devices
• CPC Class Codes: G06F 2201/81 Threshold
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A storage system maintains a journal of journal entries and at lease one snapshot of one or more data volumes. By assigning a unique sequence number to journal and snapshot, it is easy to find a journal which can be applied to the snapshot. A technique is described for detecting an overflow condition of running out of journal space and recovering the journal space.

Claims

1. A storage system comprising:

a first data volume storing data of a first journal group;

a second data volume storing data of a second journal group;

snapshot storing areas storing at least one snapshot of at least a portion of each of the first and second data volumes;

a first journal storing area storing journal entries associated with the first journal group; and

a second journal storing area storing journal entries associated with the second journal group;

wherein the first journal storing area is configured to permit data recovery within a first determined range by using said at least one snapshot of at least a portion of the first data volume and a portion of the journal entries stored in the first journal storing area,

wherein the second journal storing area is configured to permit data recovery within a second determined range by using said at least one snapshot of at least a portion of the second data volume and a portion of the journal entries stored in the second journal storing area,

wherein the storage system releases at least one of the stored journal entries from the first or second journal storing areas while permitting data recovery within the first and second determined ranges; and

wherein in order to recover data of a portion of the first or second data volume at a specific point in time within the first or second determined range, the storage system recovers the data of the portion of the first or second data volumes at the specific point in time by using said at least one snapshot and a portion of the stored journal entries.

2. The storage system of claim 1, wherein the storage system releases at least one of the stored journal entries from the first or second journal storing areas based on the configuration of the first and second journal storing areas.

3. The storage system of claim 2, wherein the at least one of the stored journal entries is released from the first or second journal storing area after a snapshot of at least a portion of the first or second data volume is taken.

4. The storage system of claim 1, wherein the first and second determined ranges are determined by an administrator.

5. The storage system of claim 1, wherein the first and second journal storing areas are configured with at least one storage volume.

6. The storage system of claim 1, wherein the snapshot storing areas and the first and second journal storing areas are configured with at least one storage volume.

7. The storage system of claim 1, wherein the first journal storing area is configured by setting a first threshold in a first journal volume, the second journal storing area is configured by setting a second threshold in a second journal volume, and the first and second thresholds specify a capacity of the first and second journal storing areas, respectively.

8. The storage system of claim 1, wherein the first determined range is different from the second determined range.

9. The storage system of claim 1, wherein the first and second journal storing areas have capacities that are variable.

10. The storage system of claim 1, wherein the specific point in time is specified by an administrator.

11. A storage system comprising:

a first data volume storing data of a first journal group;

a second data volume storing data of a second journal group;

snapshot storing areas storing at least one snapshot of at least a portion of each of the first and second data volumes;

a first journal storing area storing journal entries associated with the first journal group; and

a second journal storing area storing journal entries associated with the second journal group;

wherein the first journal storing area is configured to permit data recovery within a first determined range by using said at least one snapshot of at least a portion of the first data volume and a portion of the journal entries stored in the first journal storing area,

wherein the second journal storing area is configured to permit data recovery within a second determined range by using said at least one snapshot of at least a portion of the second data volume and a portion of the journal entries stored in the second journal storing area,

wherein the storage system releases at least one of the stored journal entries from the first or second journal storing areas while permitting data recovery within the first and second determined ranges; and

wherein, in response to a request, specifying a specific point in time within the first or second determined range, to recover data of a portion of the first or second data volume, the storage system recovers the data of the portion of the first or second data volume at the specific point in time by using said at least one snapshot and a portion of the stored journal entries.

12. The storage system of claim 11, wherein the storage system releases at least one of the stored journal entries from the first or second journal storing area based on the configuration of the first and second journal storing areas.

13. The storage system of claim 12, wherein the at least one of the stored journal entries is released from the first or second journal storing area after a snapshot of at least a portion of the first or second data volume is taken.

14. The storage system of claim 12, wherein the request, specifying the specific point in time within the first or second determined range, is issued by an administrator.

15. The storage system of claim 11, wherein the first and second determined ranges are determined by an administrator.

16. The storage system of claim 11, wherein the first and second journal storing areas are configured with at least one storage volume.

17. The storage system of claim 11, wherein the snapshot storing areas and the first and second journal storing areas are configured with at least one storage volume.

18. The storage system of claim 11, wherein the first journal storing area is configured by setting a first threshold in a first journal volume, the second journal storing area is configured by setting a second threshold in a second journal volume, and the first and second thresholds specify a capacity of the first and second journal storing areas, respectively.

19. The storage system of claim 11, wherein the first determined range is different from the second determined range.

20. The storage system of claim 11, wherein the first and second journal storing areas have capacities that are variable.