Storage system

• US 6,681,303 B1
• Filed: 08/19/1999
• Issued: 01/20/2004
• Est. Priority Date: 08/20/1998
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamamoto, Akira, Oeda, Takashi, Yamagami, Kenji, Arai, Kouji, Watanabe, Haruaki, Nakamura, Katsunori
• Primary Examiner(s): Ellis, Kevin L.
• Application Number:
  US09/376,991
• Time in Patent Office: 1,615 Days
• Field of Search: 711/112, 711/161, 711/162, 707/204, 714/6
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2082 Data synchronisation

Abstract

In a storage system, a logical volume is divided into a plurality of small areas called logical storage devices and only such an area designated by a user is made an object of remote copying or migratory copying. Also, there is provided a unit for forming a logical volume from any logical storage device of any RAID group. Thereby, the reduction of the deterioration in performance at the time of remote copying, the reduction of a storage area to be assigned to a secondary site as a copy destination, the shortening of a time required for migratory copying and the assignment of any area of a logical volume on any RAID group are enabled.

Claims

1. A method of performing a remote copying between two storage systems used as external memories of a CPU which issues a request for access to a logical volume, wherein in one of the two storage systems serving as a copy source, a partial area of a logical volume on the copy source storage system is designated and data of the designated partial area of the logical volume is transferred to a logical volume on the other of the two storage systems as a copy destination without the intervention of said CPU, whereas in the copy destination storage system, the data of the partial area transferred from the copy source storage system is written into the logical volume on the copy destination storage system.

2. A method of performing a migratory copying with which data migrates between two storage systems used as external memories of a CPU which issues a request for access to a logical volume, wherein in one of the two storage systems serving as a copy destination, a partial area of a logical volume on the other of the two storage systems serving as a copy source is designated, data of the designated partial area of the logical volume on the copy source storage system is read from the logical volume on the copy source storage system without the intervention of said CPU, and the read data is written into a logical volume on the copy destination storage system.

3. A method of copying data between storage systems used as a recording medium of a CPU, said method comprising the steps of:

receiving a user instruction which designates a partial area of a logical volume in a first storage system;

sending data and management information regarding said data to be copied into a second storage system stored in said partial area of the logical volume to said second storage system;

writing said data and said management information to a logical volume in the second storage system; and

processing said management information of said logical volume in the second storage system so that said CPU can access said data stored in the logical volume in the second storage system.

4. A method according to claim 3, wherein said sending step comprises the steps of:

setting an indicator which shows said partial area for a logical volume in the first storage system; and

sending said data from said first storage system to said second storage system according to said indicator.

5. A method according to claim 4, wherein said sending step comprises the steps of:

receiving an instruction to write data to a logical volume in the first storage system;

determining whether said instruction is a write request to said partial area of a logical volume in the first storage system in response to said indicator; and

transmitting said data to the second storage system if said instruction is a write request to said partial area of a logical volume in the first storage system.

6. A method according to claim 3, wherein said management information includes an address size for said data being stored and said processing step comprises the step of:

changing said management information so that capacity of said logical volume in the second storage system is same as capacity of said logical volume in the first storage system.

7. A method according to claim 3, wherein said processing step comprises the step of:

deleting information regarding data not written in said logical volume in the second storage system from said management information in said logical volume in the second storage system.

8. A method according to claim 3, wherein said second storage system is a backup of said first storage system.

9. A method according to claim 3, wherein said user instruction includes a logical volume number of said logical volume in said first storage system.

10. A method according to claim 3, wherein said user instruction includes address information designating said partial area of a logical volume in the first storage system.

11. A storage system coupled to another storage system, comprising:

a storage device; and

a controller controlling said storage device,

wherein said controller has an indicator designating a partial area of a logical volume in said storage device and when said controller receives an instruction to write data to a storage area in said storage device, said controller transfers said data to said another storage system if said storage area in said storage device is designated by said indicator.

12. A storage system according to claim 11, wherein said another storage system is a backup of the storage system, and information regarding a storage area in said another storage system for storing said data is processed so that a CPU can access to said data transferred to said storage area in said another storage system.

13. A storage system according to claim 12, wherein said indicator is set in accordance with a user instruction received by said controller.

14. A storage system according to claim 12, wherein said controller has a memory where said indicator is stored.

15. A method according to claim 13, wherein said user instruction includes a logical volume number of said logical volume in said first storage system.

16. A method according to claim 13, wherein said user instruction includes address information designating said partial area of a logical volume in the first storage system.

17. A storage system coupled to another storage system, comprising:

a storage device; and

a controller controlling said storage device,

wherein said controller receives data stored in a partial area of a logical volume of said another storage system, writes said data to a logical volume of the storage system, and processes management information of said logical volume of said storage system, so that data stored in said logical volume of said storage system can be accessed from a CPU coupled to the storage system.

18. A storage system according to claim 17, wherein said controller deletes file management information regarding data not written in said logical volume in the second storage system from said management information in said logical volume in the second storage system.

19. A storage system according to claim 17, wherein said controller changes said management information so that capacity of said logical volume of the second storage system is same as capacity of said logical volume of said another storage system.

20. An information system coupled to a CPU, comprising:

a first and a second storage system each of which comprises a controller and a storage device controlled by said controller; and

an inter controller path via which said first storage system and said second storage system are coupled,

wherein said first storage system receives a user instruction which designates a partial area of a logical volume in the first storage system and sends data stored in said partial area of the logical volume to said second storage system via said inter controller path, and

wherein said second storage system writes said data to a logical volume in said second storage system and processes management information of said logical volume in the second storage system, so that said CPU can access said data stored in said logical volume in the second storage system.

21. An information system according to claim 20, wherein said first storage system sets an indicator which shows said partial area of a logical volume and sends data to the second storage system according to said indicator.

22. An information system according to claim 20, wherein said controller of said second storage system changes said management information of said logical volume in the second storage system so that capacity of said logical volume in the second storage system is same as capacity of said logical volume in the first storage system.

23. An information system according to claim 20, wherein said controller of said second storage system deletes information regarding data not copied to said logical volume in the second storage system from file management information copied to said logical volume in the second storage system.

24. An information system according to claim 20, wherein said first storage system receives an instruction to write data to a logical volume in the first storage system, determines whether said instruction is a write request to a storage area indicated by said indicator, and transmits data to the second storage system if said instruction is a write request to the second storage system.

25. An information system according to claim 20, wherein said second storage system is a backup of said first storage system.

26. A method according to claim 20, wherein said user instruction includes a logical volume number of said logical volume in said first storage system.

27. A method according to claim 20, wherein said user instruction includes address information designating said partial area of a logical volume in the first storage system.

28. A method of copying data between storage systems, each of which has a controller and a disk device and is used as a recording medium of a CPU, said method comprising the steps of:

a receiving step for receiving a user instruction which designates a partial area of a first logical volume in a first storage system;

a request sending step for sending a copy request from said first storage system to a second storage system;

an assigning step for assigning a second logical volume in said second storage system if said second logical volume can be assigned according to said copy request;

a reporting step for reporting said first storage system that it is impossible to generate a copy from said second storage system, if said second logical volume cannot be assigned according to said copy request;

a data sending step for sending data stored in said partial area of said first logical volume from said first storage system to said second storage system if said second logical volume is assigned in said second storage system; and

a data writing step for writing said data received from said first storage system into said second logical volume.

29. A method of copying data according to claim 28, wherein said second storage system reports impossibility of copying to said first storage system if enough capacity corresponding to a requested storage capacity included in said copy request does not exist in said second storage system.

30. A method of copying data according to claim 28, wherein said second storage system reports impossibility of copying to said first storage system if an emulation type requested in said copy request has not been defined in said second storage system.

31. A storage system coupled to another storage system, comprising:

a storage device; and

a controller controlling said storage device,

wherein said controller receives a copy request including a parameter designating a partial area of a first volume in said another storage system from said another storage system,

assigns a second volume in said storage system if said second volume can be assigned according to said parameter;

reports to said another storage system that it is impossible to generate a copy, if said second volume cannot be assigned according to said parameter;

receives data stored in said partial area of the first volume from said another storage system, if said second volume can be assigned; and

writes said data received from said another storage system into said second volume of the storage system.

32. A storage system according to claim 31, wherein said storage system reports impossibility of copying to said another storage system if enough storage capacity corresponding to said parameter does not exist in said storage system.

33. A storage system according to claim 31, wherein said storage system reports impossibility of copying to said another storage system if emulation type requested in said copy request has not been defined in said storage system.