Computer system, storage system, management computer, and backup management method

• US 20070112894A1
• Filed: 01/12/2006
• Published: 05/17/2007
• Est. Priority Date: 11/15/2005
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Okada, Wataru, Sato, Masahide
• Application Number:
  US11/330,321
• Publication Number:
  US 20070112894A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

A computer system includes one or a plurality of host computers, a storage system including a disk device having a data volume for reading and writing data by the host computer, and a management computer for connecting the host computer and the storage system. The storage system obtains a snapshot of the data volume at a specific time point, holds the written journal after the specific time point, recovers the snapshot with the snapshot obtained at the time point near a recovery point, as the base, in the recovery, by applying the journal to the snapshot, specifies the journal depending on the snapshot or journal as a releasing target by using an order relationship used for determining the order between the snapshot, serving as the base, in the recovery, and the journal applied to the snapshot upon releasing the snapshot or journal, and releases the specified depending journal together with the snapshot or journal as a releasing target.

Claims

1. A computer system comprising one or a plurality of host computers, a storage system comprising a disk device having a data volume for reading and writing data by said host computer, and a management computer for connecting said host computer and said storage system,

wherein said storage system obtains a snapshot of the data volume at a specific time point, holds the written journal after the specific time point, recovers, the snapshot with the snapshot obtained at the time point near a recovery point, as the base, in the recovery, by applying the journal to the snapshot, specifies the journal depending on the snapshot or journal as a releasing target by using an order relationship used for determining the order between the snapshot, serving as the base, in the recovery, and the journals applied to the snapshot upon releasing the snapshot or journal, and releases the specified depending journal together with the snapshot or journal as a releasing target.

2. A computer system according to claim 1, wherein said storage system determines whether or not the recovery point of the depending journal is maintained.

3. A computer system according to claim 1, wherein said storage system determines that the recovery point of the depending journal is maintained, saves data overwritten upon applying the journal depending on the snapshot as a releasing target to the snapshot as a releasing target, and maintains the recovery point of the journal depending on the snapshot as a releasing target.

4. A computer system according to claim 1, wherein said storage system determines that the recovery point of the depending journal is maintained, saves data overwritten upon applying the journal depending on the snapshot, to which the journal as a releasing target is to be applied, to the snapshot, and maintains the recovery point of the journal depending on the snapshot, to which the journal as a releasing target is to be applied.

5. A computer system according to claim 1, wherein said management computer determines whether or not the amount of used journal is over a predetermined value and, when it is over the predetermined value, sends a request for releasing the oldest journal to said storage system.

6. A computer system according to claim 1, wherein said management computer sends a request for obtaining the snapshot to said storage system and for releasing the oldest snapshot.

7. A storage system comprising a disk device having a data volume for reading and writing data by one or a plurality of host computers, said host computer and a management computer forming a computer system,

wherein said storage system comprises a CPU, a memory, and a connecting interface, and obtains a snapshot of the data volume at a specific time point, holds the written journal after the specific time point, recovers the snapshot with the snapshot obtained at the time point near a recovery point, as the base, in the recovery, by applying the journal to the snapshot, specifies the journal depending on the snapshot or journal as a releasing target by using an order relationship used for determining the order between the snapshot, serving as the base, in the recovery, and the journals applied to the snapshot upon releasing the snapshot or journal, and releases the specified depending journal together with the snapshot or journal as a releasing target.

8. A storage system according to claim 7, wherein said storage system determines whether or not the recovery point of the depending journal is maintained.

9. A storage system according to claim 7, wherein said storage system determines that the recovery point of the depending journal is maintained, saves data overwritten upon applying the journal depending on the snapshot as a releasing target to the snapshot as a releasing target, and maintains the recovery point of the journal depending on the snapshot as a releasing target.

10. A storage system according to claim 7, wherein said storage system determines that the recovery point of the depending journal is maintained, saves data overwritten upon applying the journal depending on the snapshot, to which the journal as a releasing target is to be applied, to the snapshot, and maintains the recovery point of the journal depending on the snapshot, to which the journal as a releasing target is to be applied.

11. A management computer connected to a storage system, said storage system comprising one or a plurality of host computers and a disk device having a data volume for writing and reading data by said host computer, said storage system releasing a snapshot or a journal as a releasing target and a depending journal,

wherein said management system comprises a CPU, a memory, and a connecting interface, determines whether or not the amount of used journal to be held by said storage system is over a predetermined value, when the amount of used journal is over a predetermined value, and sends a request for releasing the oldest journal to said storage system.

12. A management computer according to claim 11, wherein said management computer sends a request for obtaining a snapshot and for releasing the oldest snapshot to said storage system.

13. A backup management method of a computer system, said computer system comprising one or a plurality of host computers, a storage system comprising a disk device having a data volume for writing and reading data by said host computer, and a management computer for connecting said host computer and said storage system,

said backup management method comprising the steps of:

specifying a journal depending on a snapshot or journal as a releasing target by using an order relationship used for determining the order between the snapshot, serving as the base, in the recovery upon releasing the snapshot or journal; and

releasing the specified journal together with the snapshot or journal as a releasing target.

14. A backup management method according to claim 13, further comprising the step of:

determining whether or not the recovery point of the depending journal is maintained.

15. A backup management method according to claim 13, further comprising the steps of:

determining whether or not the recovery point of the depending journal is maintained;

saving data overwritten upon applying the journal depending on the snapshot as a releasing target to the snapshot as a releasing target; and

maintaining the recovery point of the journal depending on the snapshot as a releasing target.

16. A backup management method according to claim 13, further comprising the steps of:

determining whether or not the recovery point of the depending journal is maintained;

saving data overwritten upon applying the journal depending on the snapshot as a releasing target, to which the journal as a releasing target is to be applied; and

maintaining the recovery point of the journal depending on the snapshot as a releasing target, to which the journal as a releasing target is to be applied.

17. A backup management method according to claim 13, further comprising the steps of:

determining whether or not the amount of used journal is over a predetermined value; and

sending a request for releasing the oldest journal to said storage system, upon determining that the amount of used journal is over the predetermined value.

18. A backup management method according to claim 13, further comprising the steps of:

sending a request for obtaining the snapshot and releasing the oldest snapshot to said storage system.