Data replication among storage systems

• US 8,566,284 B2
• Filed: 07/20/2012
• Issued: 10/22/2013
• Est. Priority Date: 06/27/2003
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hirakawa, Yusuke, Arakawa, Hiroshi, Takeda, Takahiko, Sato, Takao
• Primary Examiner(s): GIRMA, ANTENEH B
• Application Number:
  US13/554,163
• Publication Number:
  US 20120311252A1
• Time in Patent Office: 459 Days
• Field of Search: None
• US Class Current: 707/640
• 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 remote copy system comprising:

a first storage system coupled to a host computer and having an original volume configured by a plurality of storage devices in the first storage system;

a second storage system coupled to the first storage system and having a first logical volume and a first journal volume configured by a plurality of storage devices in the second storage system; and

a third storage system coupled to the second storage system and having a second logical volume configured by a plurality of storage devices in the third storage system,

wherein, when the original volume is updated with a write data, the first logical volume is updated with the write data and journal data including the write data and update information corresponding to the write data is written to the first journal volume,

wherein, in response to a request for a transmission of the journal data received from the third storage system, the second storage system sends the journal data to the third storage system and the third storage system updates the second logical volume with the write data based on the journal data.

2. A remote copy system according to claim 1,

wherein the first logical volume and the second logical volume configure a copy pair where the first logical volume is managed as a primary volume and the second logical volume is managed as a secondary volume.

3. A remote copy system according to claim 1,

wherein the update information includes the write order of the write data and the write address of the write data.

4. A remote copy system according to claim 1,

wherein the first journal volume temporarily stores the journal data and the journal data is deleted after the write data in the journal data is written to the second logical volume.

5. A remote copy system according to claim 1,

wherein the third storage system has a second journal volume, and

wherein when the third storage system receives the journal data from the second storage system, the third storage system stores the journal data in the second journal volume and uses the journal data in the second journal volume for updating the second logical volume with the write data based on the journal data.

6. A remote copy system according to claim 5,

wherein the third storage system sends the request for a transmission of the journal data to the second storage system repeatedly and decides a timing of the request for a transmission of the journal data according to a storage capacity of the second journal volume.

7. A remote copy method in a system having a first storage system coupled to a host computer and having an original volume configured by a plurality of storage devices in the first storage system;

a second storage system coupled to the first storage system and having a first logical volume and a first journal volume configured by a plurality of storage devices in the second storage system; and

a third storage system coupled to the second storage system and having a second logical volume configured by a plurality of storage devices in the third storage system, the method comprising the steps of;

when the original volume in the first storage system is updated with a write data, updating the first logical volume in the second storage system with the write data;

writing journal data including the write data and update information corresponding to the write data to the first journal volume in the second storage system;

receiving, by the second storage system, a request for a transmission of the journal data from the third storage system;

sending, by the second storage system, the journal data to the third storage system; and

updating, by the third storage system, the second logical volume in the third storage system with the write data based on the journal data.

8. A remote copy method according to claim 7, further comprising the step of:

configuring a copy pair with the first logical volume and the second logical volume, where the first logical volume is managed as a primary volume and the second logical volume is managed as a secondary volume.

9. A remote copy method according to claim 7,

wherein the update information includes the write order of the write data and the write address of the write data.

10. A remote copy method according to claim 7,

wherein the first journal volume temporarily stores the journal data and the journal data is deleted after the write data in the journal data is written to the second logical volume.

11. A remote copy method according to claim 7,

wherein the third storage system has a second journal volume, and

wherein when the third storage system receives the journal data from the second storage system, the third storage system stores the journal data in the second journal volume and uses the journal data in the second journal volume for updating the second logical volume with the write data based on the journal data.

12. A remote copy method according to claim 11,

wherein the third storage system sends the request for a transmission of the journal data to the second storage system repeatedly and decides a timing of the request for a transmission of the journal data according to a storage capacity of the second journal volume.