Integrated remote replication in hierarchical storage systems

• US 20090300079A1
• Filed: 05/30/2008
• Published: 12/03/2009
• Est. Priority Date: 05/30/2008
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shitomi, Hidehisa
• Granted Patent: US 8,170,990 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems
• CPC Class Codes: G06F 16/1824 implemented using Network-attached Storage [NAS] architecture distributed or networked storage systems G06F3/067; protocols for distributed storage of data in a network H04L67/1097
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0649 Lifecycle management
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• 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]

Abstract

Remote replication is implemented with hierarchical storage. In exemplary embodiments, a first storage site has a first storage system providing an upper tier of storage and a second storage system providing a lower tier of storage. A remote second storage site has third and fourth storage systems configured to receive remote replication from the first and second storage systems, respectively. When a file is migrated from the upper tier to the lower tier, a stub file is stored in place of the migrated file indicating a storage location of the migrated file on the second storage system. When copies of the migrated file and the stub file are replicated to the fourth and third storage systems, respectively, information is transmitted to the second storage site for linking the copy of the stub file at the third storage system to the copy of the migrated file at the fourth storage system.

Claims

1. An information system comprising:

a first storage site having a first storage system in communication with a second storage system, the first storage system providing an upper tier of storage having first storage characteristics and the second storage system providing a lower tier of storage having second storage characteristics; and

a second storage site remote from the first storage site having a third storage system configured to receive remote replication from the first storage system and having a fourth storage system configured to receive remote replication from the second storage system,

wherein, when a first file on the first storage system is migrated to the second storage system, a second file is created on the first storage system and stored in place of the first file indicating a storage location of the first file on the second storage system, and

wherein, when a copy of the second file is replicated to the third storage system and a copy of the first file is replicated to the fourth storage system via remote replication, information is transmitted to the second storage site for linking the copy of the second file at the third storage system to the copy of the first file at the fourth storage system.

2. The information system according to claim 1,

wherein the first storage system and the third storage system are network attached storage (NAS) systems implementing a file-based protocol for sending and receiving communications,

wherein the second storage system and the fourth storage system are contents addressable storage (CAS) systems, and

wherein the first storage system is configured to migrate the first file automatically to the second storage system when a condition established in a predetermined migration policy is met.

3. The information system according to claim 1,

wherein the first storage system, the second storage system, the third storage system and the fourth storage system are network attached storage (NAS) systems implementing a file-based protocol for sending and receiving communications.

4. The information system according to claim 1, further comprising:

a first management computer in communication with the first storage system,

wherein, when the copy of the second file is replicated to the third storage system, the first management computer is configured to determine a location of the copy of the first file on the fourth storage system from management data and transmit this location of the copy of the first file with the information for linking the copy of the second file with the copy of the first file.

5. The information system according to claim 4, further comprising:

a second management computer at the second site, the second management computer configured to receive the information transmitted from the first management computer and instruct linking of the copy of the second file with the copy of the first file in accordance with the information received.

6. The information system according to claim 1, further comprising:

a hierarchical management module containing hierarchical management data including predetermined conditions for file migration,

wherein, the first file is migrated to the second storage system as a result of a corresponding predetermined condition being met, the hierarchical management server being configured to issue an instruction for migrating the first file from the first storage system to the second storage system when the corresponding predetermined condition is met.

7. The information system according to claim 6, further comprising:

a migration module, the migration module being configured to receive the instruction for migrating the first file and to carry out migration of the first file from the first storage system to the second storage system.

8. The information system according to claim 7,

wherein the migration module and hierarchical management module are located on the first storage system.

9. The information system according to claim 1,

wherein the migration module and hierarchical management module are located on a server computer in communication with the first storage system and the second storage system.

10. The information system according to claim 1, further comprising:

a first remote copy module located on the first storage system for carrying out the remote replication from the first storage system to the third storage system; and

a second remote copy module located on the second storage system for carrying out the remote replication from the second storage system to the fourth storage system independently of the remote replication from the first storage system to the third storage system.

11. The information system according to claim 1,

wherein, following completion of the replication of the copy of the second file to the third storage system, when the replication of the copy of the first file to the fourth storage system is not complete, linking of the copy of the second file to the copy of the first file is delayed until replication of the copy of the first file to the fourth storage system is completed.

12. A method for carrying out remote replication in a hierarchical storage arrangement, the method comprising:

providing a first storage system in communication with a second storage system at a first storage site, the first storage system providing an upper tier of storage having first storage characteristics and the second storage system providing a lower tier of storage having second storage characteristics;

configuring a third storage system at a second storage site remote from the first storage site to receive remote replication from the first storage system;

configuring a fourth storage system to receive remote replication from the second storage system at the second storage site;

migrating a first file on the first storage system to the second storage system;

creating a second file on the first storage system as a result of the migration, the second file being stored in place of the first file indicating a storage location of the first file on the second storage system;

replicating a copy of the first file to the third storage system and a copy of the second file to the fourth storage system via remote replication; and

transmitting information to the second storage site for linking the copy of the second file at the third storage system to the copy of the first file at the fourth storage system.

13. The method according to claim 12, further including a step of

following failure at the first storage site, continuing operations associated with the first file by accessing the copy of the first file stored at the fourth storage system via the copy of the second file stored in the third storage system.

14. The method according to claim 12, further including a step of

providing a management computer at the first storage site, the management computer obtaining the information for linking the copy of the second file at the third storage system to the copy of the first file at the fourth storage system from a hierarchical storage management module at the first storage site and transmitting the information to the second storage site.

15. The method according to claim 12, further including steps of

determining, following completion of replication of the copy of the second file to the third storage system, whether replication of the copy of the first file to the fourth storage system is complete;

and

when the replication of the copy of the first file to the fourth storage system is not complete, delaying linking of the copy of the second file to the copy of the first file is until replication of the copy of the first file to the fourth storage system is completed.

16. A method for carrying out remote replication in a hierarchical storage arrangement, the method comprising:

providing a first storage system in communication with a second storage system at a first storage site, the first storage system providing an upper tier of storage having first storage characteristics and the second storage system providing a lower tier of storage having second storage characteristics;

configuring a third storage system at a second storage site remote from the first storage site to receive remote replication from the first storage system;

migrating a first file on the first storage system to the second storage system;

creating a second file on the first storage system as a result of the migration, the second file being stored in place of the first file indicating a storage location of the first file on the second storage system;

providing a management computer at the first storage site, the management computer having a remote copy module located thereon for carrying out the remote replication from the first storage site to the second storage site; and

replicating a copy of the first file to the third storage system via the remote copy module.

17. The method according to claim 16, further including steps of

providing network attached storage (NAS) systems implementing a file-based protocol for sending and receiving communications as the first and third storage systems;

and

providing a NAS system or a contents addressable storage (CAS) system as the second storage system.

18. The method according to claim 16, further including a step of

migrating the first file automatically to the second storage system when a condition established in a predetermined migration policy is met.

19. The method according to claim 16, further including steps of

configuring a fourth storage system to receive remote replication from the second storage system at the second storage site;

and

transmitting information to the second storage site for migrating the copy of first file to the fourth storage system and creating a third file on the third storage system as a result of the migration, the third file being stored in place of the copy first file indicating a storage location of the copy of the first file on the fourth storage system.

20. The method according to claim 19, further including steps of

providing network attached storage (NAS) systems implementing a file-based protocol for sending and receiving communications as the first and third storage systems;

providing contents addressable storage (CAS) systems as the second and fourth storage systems.