Method and apparatus for backup and recovery using storage based journaling

• US 7,783,848 B2
• Filed: 05/22/2007
• Issued: 08/24/2010
• Est. Priority Date: 06/26/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamagami, Kenji
• Primary Examiner(s): PATEL, HETUL B
• Application Number:
  US11/802,278
• Publication Number:
  US 20070220221A1
• Time in Patent Office: 1,190 Days
• Field of Search: 711/159, 711/161, 711/162
• 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 being adapted to be coupled to a first host computer and a second host computer via a network comprising:

a first data volume storing write data from the first host computer, the first data volume being associated with a first journal group to which an order of write operations from the first host computer is guaranteed;

a second data volume storing write data from the second host computer, the second data volume being associated with a second journal group to which an order of write operations from the second host computer is guaranteed;

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 write data to the first journal group; and

a second journal storing area storing journal entries associated with write data to 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 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 volume at the specific point in time, and

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 while permitting data recovery within the first and second determined ranges.

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

3. 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.

4. 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.

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

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

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

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

9. A storage system coupled to plurality of host computers via a network comprising:

a first data volume storing write data from a first application on one of the plurality of host computers, the first data volume being associated with a first journal group to which an order of write operations from the first application is guaranteed;

a second data volume storing write data from a second application on one of the plurality of host computers, the second data volume being associated with a second journal group to which an order of write operations from the second application is guaranteed;

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 write data to the first journal group; and

a second journal storing area storing journal entries associated with write data to 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 is capable of recovering data of a portion of the first or second data volume at a specific point in time within the first or second determined ranges, and

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 while permitting data recovery within the first and second determined ranges.

10. The storage system of claim 9, wherein the first and second journal storing areas are configured with at least one storage volume.

11. The storage system of claim 9, wherein the snapshot storing areas and the first and second journal storing areas are configured with at least one storage volume.

12. The storage system of claim 9, 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.

13. The storage system of claim 9, wherein the first determined range is different from the second determined range.

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

15. The storage system of claim 9, the first and second determined ranges are determined by an administrator.

16. The storage system of claim 9, wherein the specific point in time is specified by an administrator.