Remote copy system

• US 7,606,940 B2
• Filed: 09/28/2006
• Issued: 10/20/2009
• Est. Priority Date: 06/23/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamagami, Kenji
• Primary Examiner(s): NGUYEN, THANH T
• Application Number:
  US11/540,073
• Publication Number:
  US 20070027939A1
• Time in Patent Office: 1,118 Days
• Field of Search: 709/246, 709/204, 709/202, 709/201, 711/161, 711/156, 714/6, 714/16
• US Class Current: 709/246
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2076 Synchronous techniques
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 2201/855 Details of asynchronous mirroring using a journal to transfer not-yet-mirrored changes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• 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: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/59 Providing operational support to end devices by off-loading in the network or by emulation, e.g. when they are unavailable
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• 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 remote copy system includes a first storage system including a first storage controller and a first data volume. The first storage controller is configured to control data access requests to the first data volume. The first storage system is configured to store write data in the first data volume upon receiving a write request from a first host associated with the first storage system and generate a journal including control data and journal data. A second storage system includes a journal volume and configured to receive and store the journal generated by the first storage system in the journal volume. A third storage system includes a second data volume and configured to receive the journal from the second storage system and store the journal data of the journal to the second storage system according to information provided in the control data.

Claims

1. A remote copy system, comprising:

a first storage system coupled to the first storage system and including a first storage controller and a first data volume, the first storage controller being configured to receive a write request from a first host associated with the first storage system and to store write data associated with the write request to the first data volume;

a second storage system including a second storage controller and a second data volume, the second storage controller receiving first data containing the write data to copy the stored data in the first data volume to the second data volume; and

a third storage system coupled to the second storage system and including a third storage controller and a third data volume, the third storage controller receiving second data containing a journal to copy the stored data in the first data volume to the third data volume, wherein the journal comprises the write data and a sequence number indicating write ordering to the first data volume;

wherein the write request from the first host to the first storage system completes after the first data is received by the second storage system, wherein the write request from the first host to the first storage system completes independently of the second data being received by the third storage system,

wherein write data to be stored on the third data volume is generated according to the write order provided by the sequence number of the journal that is contained in the second data,

wherein the second storage system maintains status information indicating whether a corresponding data to the write data received at the second storage system is sent to the third storage system.

2. The remote copy system of claim 1, wherein the status information is updated after the third storage system receives the corresponding data.

3. The remote copy system of claim 1, wherein the status information is maintained by using a pointer associated with a journal volume resided in the second storage system.

4. The remote copy system of claim 1, further comprising:

a second host coupled to the second storage system, wherein the second storage system is configured to function as a primary storage system if the first storage system experiences failure.

5. The remote copy system of claim 1, further comprising a third host coupled to the third storage system, wherein the third storage system is configured to replace the first storage system as a primary storage system if the first storage system experiences failure.

6. The remote copy system of claim 1, wherein the journal further includes a time when the write data are stored in the first data volume based on the write request from the first host.

7. The remote copy system of claim 1, wherein the journal is received at the third data volume after the write data are copied to the second storage system to secure the write data when the first storage system experiences failure.

8. A remote copy system, comprising:

a first storage system coupled to the first storage system and including a first storage controller and a first data volume, the first storage controller being configured to receive a write request from a first host associated with the first storage system and to store write data associated with the write request to the first data volume;

second storage system including a second storage controller and a second data volume, the second storage controller being configured to synchronously receive first data containing the write data to copy the stored data in the first data volume to the second data volume; and

a third storage system coupled to the second storage system and including a third storage controller and a third data volume, the third storage controller being configured to asynchronously receive second data containing a journal to copy the stored data in the first data volume to the third data volume,

wherein the journal comprises the write data and a sequence number indicating write ordering to the first data volume,

wherein write data to be stored on the third data volume is generated according to the write order provided by the sequence number,

wherein the second storage system maintains status information indicating progress of an asynchronous remote copy operation with the third storage system.

9. The remote copy system of claim 8, wherein the status information is updated after the third storage system receives the corresponding data.

10. The remote copy system of claim 8, wherein the status information is maintained by using a pointer associated with a journal volume resided in the second storage system.

11. The remote copy system of claim 8, further comprising:

a second host coupled to the second storage system, wherein the second storage system is configured to function as a primary storage system if the first storage system experiences failure.

12. The remote copy system of claim 8, further comprising a third host coupled to the third storage system, wherein the third storage system is configured to replace the first storage system as a primary storage system if the first storage system experiences failure.

13. The remote copy system of claim 8, wherein the journal further includes a time when the write data are stored in the first data volume based on the write request from the first host.

14. The remote copy system of claim 8, wherein the journal is received at the third data volume after the write data are copied to the second storage system to secure the write data when the first storage system experiences failure.