Data replication among storage systems

• US 8,135,671 B2
• Filed: 03/08/2007
• Issued: 03/13/2012
• Est. Priority Date: 06/27/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hirakawa, Yusuke, Arakawa, Hiroshi, Takeda, Takahiko, Sato, Takao
• Primary Examiner(s): Fleurantin, Jean B
• Assistant Examiner(s): GIRMA, ANTENEH B
• Application Number:
  US11/715,480
• Publication Number:
  US 20070168361A1
• Time in Patent Office: 1,832 Days
• Field of Search: 707/204
• US Class Current: 707/613
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 16/22 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: G06F 2201/855 Details of asynchronous mirroring using a journal to transfer not-yet-mirrored changes
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A first storage system stores information relating to the updating of data stored in that system as a journal. More specifically, the journal is composed of a copy of data that was used for updating and update information such as a write command used during updating. Furthermore, the second storage system acquires the journal via a communication line between the first storage system and the second storage system. The second storage system holds a duplicate of the data held by the first storage system and updates the data corresponding to the data of the first storage system in the data update order of the first storage system by using the journal.

Claims

1. A system comprising:

a first storage system coupled to a host device which sends data to and receives data from said host device; and

a second storage system coupled to said first storage system,

wherein said first storage system comprises;

a plurality of first disk drives associated with a first volume and a second volume, the first volume being an original volume which is accessed by said host device; and

a first cache memory storing data, which are sent from said host device to said first volume, wherein replicated data of said data are generated and stored in said first cache memory and are to be sent to said second storage system,

wherein said second volume is used to store at least a portion of said replicated data if an amount of said replicated data stored in said first cache memory has reached an amount designated by a user; and

wherein said second storage system comprises;

a second cache memory storing said replicated data after being sent from said first storage system;

a plurality of second disk drives associated with a third volume and a fourth volume, said third volume being used to store at least a portion of said replicated data sent from said first storage system if an amount of said replicated data stored in said second cache memory has reached an amount designated by a user, said fourth volume being a secondary volume that is paired with said first volume,

wherein said replicated data stored in said second cache memory or in said third volume is stored into said fourth volume.

2. The system according to claim 1,

wherein said first storage system sends said replicated data stored in said first cache memory or in said second volume to said second storage system via a plurality of connection paths.

3. The system according to claim 1,

wherein a path which couples said host computer to said first storage system and another path which couples said first storage system to said second storage system are different from each other.

4. The system according to claim 1,

wherein the amount designated by the user is designated via a first maintenance terminal coupled to said first storage system, and

wherein the amount designated by the user is designated via a second maintenance terminal coupled to said second storage system.

5. The system according to claim 1,

wherein said second storage system controls to determine time intervals of reading portions of replicated data stored in said first cache memory or in said second volume from said first storage system based on the amount of replicated data stored in said first cache memory or in said second volume.

6. The system according to claim 1,

wherein said second storage system controls to determine time intervals of reading portions of replicated data stored in said first cache memory or in said second volume from said first storage system according to an amount of traffic between said first storage system and said second storage system.

7. The system according to claim 1,

wherein said second storage system controls to determine time intervals of reading portions of replicated data stored in said first cache memory or in said second volume from said first storage system according to a processing load of said second storage system.

8. The system according to claim 1,

wherein said first storage system has information of an amount of replicated data stored in said first storage system, and

wherein said second storage system reads said information from said original storage, and controls to determine time intervals of reading portions of replicated data stored in said first cache memory or in said second volume from said first storage system based on said information.

9. The system according to claim 1,

wherein said second storage system sends, to said first storage system, a command requiring to send replicated data stored in said first storage system and information related to an update sequence of said replicated data, and

wherein said first storage system sends replicated data and said information stored in said first cache memory or in said second logical volume in response to receiving said command.

10. A system comprising a first storage system coupled to a host computer and a second storage system coupled to said first storage system:

wherein said first storage system comprises;

a plurality of first disk drives associated with a plurality of first volumes, as original volumes accessed from said host computer, the plurality of first volumes including a first volume A and a first volume B, and associated with a second volume; and

a first cache memory storing data, which are sent from said host computer to one of said first volumes, wherein replicated data are generated and stored in said first cache memory and are to be sent from said first storage system to said second storage system,

wherein said second volume is used to store at least a portion of said replicated data if an amount of said replicated data stored in said first cache memory has reached an amount designated by a user;

wherein said second storage system comprises;

a second cache memory storing said replicated data after being sent from said first storage system;

a plurality of second disk drives associated with a third volume and a plurality of fourth volumes, said third volume being used to store at least a portion of said replicated data if an amount of said replicated data stored in said second cache memory has reached an amount designated by a user, said plurality of fourth volumes being secondary volumes that are paired with said first volumes, the plurality of fourth volumes including fourth volume A being paired with said first volume A and a fourth volume B being paired with said first volume B,

wherein said second volume is allocated to a first group, which includes at least said first volume A and said first volume B, in order to maintain consistency of said first volume A and said first volume B, and

wherein said third volume is allocated to a second group, which includes at least said fourth volume A and said fourth volume B, in order to maintain consistency of said fourth volume A and said fourth volume B.

11. A system comprising a first storage system and a second storage system;

wherein said first storage system comprises a plurality of first disk drives and a first cache memory,

wherein a storage region provided from said plurality of first disk drives is divided into a plurality of storage areas including a first storage area and a second storage area, said first storage area being associated with a first volume as an original volume accessed from a host computer, said second storage area being associated with a second volume,

wherein said first cache memory stores data, which are sent from said host computer to said first volume, and which are to be transferred from said first storage system to said second storage system,

wherein said second volume is used to store at least a portion of data stored in said first cache memory after an amount of data, which are stored in said first cache memory, and are to be transferred from said first storage system to second storage system has reached an amount designated by a user,

wherein said second storage system comprises a second cache memory and a plurality of second disk drives,

wherein said second cache memory stores data transferred from said first storage system,

wherein a storage region provided from said plurality of second disk drives is divided into a plurality of storage areas including a third storage area and a fourth storage area,

wherein said third storage area is associated with a third volume, which is used to store at least a portion of said data after an amount of said data, which has been transferred from said first storage system and are stored in said second cache memory, has reached an amount designated by a user, and

wherein said fourth storage area is associated with a fourth volume as a secondary volume being paired with said first volume and storing data read from said second cache memory or from said third volume.

12. A system comprising:

a first storage system being coupled to a host computer and comprising a first controller, a plurality of disk drives and a first cache memory; and

a second storage system being coupled to said first storage system and comprising a second controller, a plurality of disk drives and a second cache memory;

wherein a storage region provided from said plurality of first disk drives is divided into a plurality of storage areas including a first storage area and a second storage area, said first storage area being associated with a first volume as an original volume accessed from said host computer, said second storage area being associated with a second volume,

wherein a storage region provided from said plurality of second disk drives is divided into a plurality of storage areas including a third storage area and a fourth storage area, said third storage area being associated with a third volume, said fourth storage area being associated with a fourth volume as a secondary volume having a pair relationship with said original volume;

wherein said first controller;

receives write data sent from said host computer to said first volume;

stores said write data into said first cache memory;

begins to use said second volume to store at least a portion of said write data received from said host computer if an amount of said data of said first cache memory reaches an amount designated by a user; and

sends said data stored in said first cache memory or in said second volume to second storage system; and

wherein said second controller;

receives said data sent by said first controller;

stores said write data that is received into said second cache memory;

begins to use said third volume to store at least a portion of said data sent by said first controller if an amount of said data sent by said first controller to said second cache memory reaches an amount designated by a user; and

stores said data stored in said second cache memory or in said third volume into said fourth volume.

13. The system according to claim 12,

wherein said first controller includes a first host adaptor and a first disk adaptor;

and

wherein said second controller includes a second host adaptor and a second disk adaptor.