Apparatus and method for online data migration with remote copy

• US 6,640,291 B2
• Filed: 08/10/2001
• Issued: 10/28/2003
• Est. Priority Date: 08/10/2001
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fujibayashi, Akira, Yamamoto, Akira
• Primary Examiner(s): Sparks, Donald
• Assistant Examiner(s): Song, Jasmine
• Application Number:
  US09/927,167
• Publication Number:
  US 20030033494A1
• Time in Patent Office: 809 Days
• Field of Search: 711/161, 711/162, 711/165, 714/6, 714/7
• US Class Current: 711/162
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

In one embodiment, a new storage system is connected to an old storage system destined for replacement. Prior to starting online data migration, remote copy configuration information from the old storage system is migrated to the new storage system. The aforementioned allows either the new storage system or the old storage system, depending on configuration, to maintain an operational remote copy function with another storage system during the online data migration. The old and new storage systems can be primary storage systems located in a local site. The old and new storage systems can also be secondary storage systems located in a site remotely located from a local site.

Claims

1. A method for performing online data migration comprising:

coupling a first storage system to a second storage system, wherein the first storage system is destined to be replaced with the second storage system;

migrating remote copy configuration information from the first storage system to the second storage system;

coupling the second storage system to a third storage system remotely located from the first storage system; and

migrating data from the first storage system to the second storage system while data are being transferred between the second storage system and the third storage system in accordance with the remote copy configuration information.

2. The method of claim 1 further comprising the following acts to be performed before migrating the remote copy configuration information from the first storage system to the second storage system:

removing a host connection between the first storage system and a host processor; and

coupling the host processor to the second storage system.

3. The method of claim 1 further comprising:

saving remote copy data as pending data in the second storage system to be written to the third storage system prior to a disruption of a remote copy connection between the first and third storage systems.

4. The method of claim 1 wherein the first storage system and the second storage system are primary storage systems, and the third storage system is a secondary storage system designated to mirror a primary storage system.

5. The method of claim 1 wherein the first storage system and the second storage system are secondary storage systems, and the third storage system is a primary storage system that is mirrored by a secondary storage system.

6. The method of claim 1 wherein the first storage system and the second storage system each includes one or more disk units.

7. A system for performing an online data migration comprising:

a first storage system located in a first location;

a second storage system located in the first location and containing remote copy configuration information, the second storage system being designated to be replaced with the first storage system, the second storage system being coupled to the first storage system during an online data migration from the second storage system to the first storage system;

a third storage system located in a second location;

a remote copy connection coupling the third storage system to a storage system in the first location, and wherein during the online data migration the remote copy connection is operable to carry data according to the remote copy configuration information.

8. The system of claim 7 wherein the first storage system and the second storage system are primary storage systems, and the third storage system is a secondary storage system designated to back-up the first storage system over the remote copy connection.

9. The system of claim 7 wherein the first storage system and the second storage system are secondary storage systems, and the third storage system is a primary storage system that is backed-up by the first storage system over the remote copy connection.

10. The system of claim 7 wherein the remote copy connection couples the third storage system to the first storage system.

11. The system of claim 7 wherein the remote copy connection couples the third storage system to the second storage system.

12. The system of claim 7 wherein the first storage system is coupled to a mainframe host processor.

13. The system of claim 7 wherein the first storage system and the second storage system are from the same manufacturer.

14. The system of claim 7 wherein the first storage system and the second storage system are from different manufacturers.

15. A method for performing online data migration comprising:

coupling a first primary storage system to a second primary storage system;

coupling the first primary storage system to a host processor;

migrating remote copy configuration information from the second primary storage system to the first primary storage system; and

migrating data from the second primary storage system to the first primary storage system while data are being transferred between the second primary storage system and a secondary storage system in accordance with the remote copy configuration information.

16. The method of claim 15 wherein the host processor includes a mainframe host processor.

17. The method of claim 15 wherein the first primary storage system, the second primary storage system, and the secondary storage system each includes one or more disk units.

18. The method of claim 15 further comprising:

removing the second primary system; and

coupling the first primary storage system to the secondary storage system after the completion of data migration from the second primary storage system to the first primary storage system.

19. The method of claim 15 further comprising:

saving remote copy data as pending data in the first primary storage system to be written to the secondary storage system when a remote copy connection between the first primary storage system and the secondary storage system becomes available.

20. The method of claim 15 wherein the first primary storage system and the second primary storage system are from the same manufacturer.