Method of and a system for recovering data in an information processing system

• US 6,658,434 B1
• Filed: 08/15/2000
• Issued: 12/02/2003
• Est. Priority Date: 02/02/2000
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamagami, Kenji, Arai, Kouji, Watanabe, Haruaki
• Primary Examiner(s): Robinson, Greta
• Assistant Examiner(s): Black, Linh
• Application Number:
  US09/639,755
• Time in Patent Office: 1,204 Days
• Field of Search: 707/200-206
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1464 for networked environments
• 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

Abstract

In an information processing system including a central processor for generating commands to process storage data stored and for executing a sequence processing and a storage subsystem including a plurality of storage media for transferring data between the plural storage media according to commands from the central processor, a data recovery method recovers data to a predetermined state upon occurrence of a failure in a sequence of processing executed by the central processor. Before execution of a sequence of processing, the central processor issues to the storage subsystem a saving request to save in the plural storage media a copy of data stored in either one of the storage media used in the sequence of processing. In response to the saving request, the storage subsystem saves a copy of data of the storage media.

Claims

1. In an information processing system including a computer for generating commands to process data stored in a storage medium and a storage system connected to said computer, said storage system including a plurality of volumes and a controller for controlling said storage system according to a command received from said computer, a data recovery method of recovering data to a predetermined state at occurrence of a failure in a sequence of processing executed by said computer, said data recovery method comprising the steps of:

issuing, to said storage system before a sequence of processing is executed by said computer, a saving request to save a copy of data stored in a first volume of said plurality of volumes, said data is used in the sequence of processing, in a second volume of said plurality of volumes;

saving by said storage system, in response to the saving request, a copy of data of said first volume into said second volume;

setting and storing by said storage system, when partial data stored in said first volume are updated, differential information designating one or a plurality of first storage areas in said first volume, in which the updated data are stored, and one or a plurality of second storage areas in said second volume, each of which corresponding to each of said one or a plurality of first storage areas;

issuing, when it is necessary to recover data stored in said first volume to a state of a predetermined point, a data recovery request including location information designating a partial area of said second volume to said storage system; and

storing, by said storage system in response to the data recovery request, the copy of data stored in said partial area of said second volume into one or a plurality of corresponding storage areas in said first volume according to said differential information.

2. A data recovery method according to claim 1, wherein said storage system further includes said a plurality of disks.

3. A data recovery method according to claim 1, wherein said saving request and said data recovery request are issued from a control terminal connected to said storage system.

4. A data recovery method according to claim 1, wherein said step of saving a copy of data includes:

storing data equal to data stored in said first volume in said second volume.

5. A data recovery method according to claim 4, wherein said step of saving a copy of data includes:

assigning one of said plurality of volumes that is not utilized as said second volume; and

copying data from said first volume to said second volume.

6. A data recovery method according to claim 1, wherein said step of storing copy of data is conducted for one or a plurality of storage areas designated by both said differential information and said location information.

7. A storage system coupled to a computer, comprising:

a plurality of volumes;

means for storing a copy of data stored in a first volume of said plurality of volumes into a second volume of said plurality of volumes, in response to a command from said computer, before a sequence of processing is executed by said computer;

means for updating, in response to a data update request from said computer, partial data stored in said first volume;

means for generating differential information for identifying one or a plurality of first storage areas in said first volume in which the updated data is stored, and one or a plurality of second storage areas in said second volume, each of which corresponding to each of said one or a plurality of first storage areas;

means for receiving a data recovery request from said computer, said data recovery request including location information designating a partial area of said second volume; and

means for replacing updated data stored in a partial area of said first volume with data saved in said partial area of said second volume, according to the differential information, in response to said data recovery request.

8. A storage system according to claim 7, wherein said plurality of volumes are included in a plurality of disks.

9. In an information processing system including a host computer and a storage system connected to said host computer, said storage system including a plurality of physical volumes and a controller for controlling said storage system according to a command received from said host computer, a data recovery method of recovering data stored in a logical volume accessed by said host computer upon occurrence of a failure in a sequence of processing executed by said host computer, said data recovery method comprising the steps of:

saving backup data of said logical volume to a storage medium;

after saving backup data, updating data stored in said logical volume according to a command received from said host computer, wherein data of said logical volume physically stored in one or a plurality of first physical volumes corresponding to said logical volume;

controlling, by said host computer, to store said backup data stored in said storage medium into one or plurality of second physical volumes;

relating by said controller, said logical volume to said one or a plurality of second physical volumes in response to a swap request from said host computer; and

after relating said logical volume to said one or a plurality of second physical volumes, accessing by said controller, data in said one or a plurality of second physical volumes said in response to an access request from said host computer to said logical volume.

10. A data recovery method according to claim 9, wherein said storage system includes a plurality of disks.

11. A storage system coupled to a host computer, comprising:

a controller for controlling said storage system according to a command received from said host computer;

a plurality of volumes; and

a host interface coupled to said host computer,

wherein said controller controls copying of data of a first volume and storing the copy of the data into a second volume according to a request received by said host interface,

after storing the copy of the data, said controller controls storing a write data received from said host computer into the first volume updating differential information designating a first storage area in first volume, in which said write data is stored, and a second storage area in the second volume corresponding to said first storage area,

said host interface receives a recovery request, from said host computer, for recovering the data stored in the first volume to a predetermined state, said recovery request includes storage area information designating a partial storage area of said second volume in which data used for recovering is stored, and

said controller controls copying of data stored in said partial area of said second volume to a corresponding storage area in the first volume according to said differential information.

12. An information processing system, comprising:

a host computer sending a command to a storage system to execute a sequential processing unit data stored in said storage system; and

a storage system coupled to said host computer, said storage system including a plurality of volumes and a controller for controlling said storage system according to a command received from said host computer,

wherein said host computer sends a saving request to said storage system to save data stored in one or a plurality of first volumes into one or a plurality of second volumes, before said host computer executes a sequential processing,

said controller controls copying of a data of said one or plurality of first volumes into said one or a plurality of second volumes according to said saving request,

said controller controls storing of a write data received from said host computer into said one or a plurality of first volumes, while said host computer executes said sequential processing,

said controller sets a differential information designating a first storage area in said one or a plurality of first volumes, in which said write data is stored, and a second storage area in said one or a plurality of second volumes corresponding to said first storage area,

said host computer sends a recovery request to said storage system, when a failure in said sequential processing occurs, said recovery request including storage area information designating a partial storage area of said one or a plurality of second volumes in which data used for recovering is stored, and

said controller controls copying of data stored in said partial storage area of said one or a plurality of second volumes designated by said storage area information to a corresponding storage area in said one or a plurality of first volumes according to said differential information.