Data replication with virtualized volumes

• US 20030188114A1
• Filed: 03/26/2002
• Published: 10/02/2003
• Est. Priority Date: 03/26/2002
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Hess, Randy, Lubbers, Clark, Leveille, Jason, Korgaonkar, Anuja, Elkington, Susan, McCarty, James, Sicola, Stephen J.
• Granted Patent: US 6,880,052 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2079 Bidirectional techniques

Abstract

A system and method for replicating data between sites in a storage area network in which storage controllers at each site implement storage virtualization. A storage cell is implemented at each site comprising at least one storage controller and a pool of physical storage coupled to the controller. A communication network couples the storage cells. A copy set comprising a logical unit (LUN) of storage, referred to as a member, in each of the storage cells is defined. As operational data transactions are performed against one of the members of a copy set, they are replicated, immediately or after a delay, in each other member of the copy set. As changes are made to dependent attributes of one member of the copy set, the change is replicated in each other member of the copy set automatically. Changes can be made in the independent attributes of each member of the copy set independently of other members of the copy set.

Claims

1. A method for replicating data in a storage area network comprising a plurality of storage cells and a communication network coupled to the storage cells, the method comprising:

implementing a virtualized logical unit (LUN) of storage in a first storage cell;

designating the LUN in a first storage cell as a source LUN;

designating at least one other storage cell as a destination;

creating a destination LUN in the at least one other storage cell such that the destination LUN is suitable to replicate the source LUN;

quiescing operational data transactions with the source LUN; and

creating an association between the source LUN and the destination LUN to form a copy set; and

resuming operational data transactions with the source virtual disk upon creation of the association.

2. The method of claim 1 further comprising communicating from the first storage cell to the at least one designated storage cell attributes that will make the destination LUN suitable to replicate the designated source LUN.

3. The method of claim 1 further comprising communicating from the destination storage cell to the first storage cell identification information allowing the first storage cell to identify logical structures of the destination LUN.

4. The method of claim 1 further comprising registering each storage cell with a name service in the communication network.

5. The method of claim 4 further comprising causing the first storage cell to use the name service to identify at least one other storage cell that is compatible with the first storage cell data replication management processes.

6. The method of claim 1 wherein the act of resuming operational data transactions occurs before all data has been copied from the source LUN to the destination LUN.

7. The method of claim 1 wherein the act of resuming operational data transactions occurs before a destination LUN has been completely allocated in the destination storage cell.

8. The method of claim 1 further comprising copying data from the source LUN to the destination LUN in a background process while operational data transactions continue to the source LUN.

9. A data replication controller for managing replication of in a storage area network, the data replication controller comprising:

a data processor system configured to implement software processes;

a pool of virtualized storage accessible through the data processor system;

processes executing in the processor to enable the data replication controller to couple to an external communication network;

processes executing in the processor for designating a virtual disk as a source virtual disk; and

processes executing in the processor to enable the data replication controller to cause a second data replication controller to create a destination virtual disk.

10. The data replication controller of claim 9 wherein the destination virtual disk has the same capacity as the source virtual disk.

11. The data replication controller of claim 9 wherein the destination virtual disk is created without user intervention.

12. The data replication controller of claim 9 wherein normal data transactions to the source virtual disk are resumed before physical storage capacity is fully allocated to the destination virtual disk.

13. The storage controller of claim 9 wherein normal data transactions to the source virtual disk are resumed before data is copied from the source virtual disk to the destination virtual disk.

14. The storage controller of claim 9 further comprising:

processes executing in the second data replication controller that implement a background copy operation to copy data from the source virtual disk to the destination virtual disk.

15. The data replication controller of claim 9 further comprising processes within the data replication controller for discovering external storage controllers coupled to the external communications network using the UUID registration information in the name server.

16. The data replication controller of claim 9 wherein the at least one port comprises a fibre channel port.

17. A storage area network (SAN) comprising:

a source disk at a first site;

a virtualized storage pool at a second site; and

a controller at the second site executing processes that implement a virtualized destination disk from the storage pool at the second site.

18. The SAN of claim 17 wherein the virtualized destination disk comprises a capacity of logical block storage that is identical to a logical block capacity of the source disk.

19. The SAN of claim 17 wherein the virtualized destination disk comprises a data protection attribute that is different from a data protection attribute of the source disk.

20. The SAN of claim 17 wherein the source disk comprises a virtualized disk implemented from a storage pool at the first site.

21. The SAN of claim 17 further comprising a process executing in the controller that responds to changes in a source disk attribute to automatically implement a corresponding change in a corresponding destination disk attribute.