Method and system for maintaining disk location via homeness

• US 8,041,736 B1
• Filed: 03/03/2010
• Issued: 10/18/2011
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Coatney, Susan M., Watanabe, Steven S., Strange, Stephen H.
• Primary Examiner(s): MIZRAHI, DIANE D
• Application Number:
  US12/716,770
• Time in Patent Office: 594 Days
• Field of Search: 707/803, 707/783, 707/784, 707/785, 707/786, 370/216, 370/230, 370/240, 709/216, 709/217, 709/223, 709/226, 714/5
• US Class Current: 707/783
• CPC Class Codes: G06F 16/122 using management policies backup systems G06F11/1446; file migration policies for HSM systems G06F16/185
• CPC Class Codes: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067

Abstract

A method and system manages ownership information about disks in a storage network without the need for an emulated, partner mode system. The method and system provides for ownership information, including a current owner and a home owner for resources, such as disks, to be stored on each disk in a storage system, as well as to be stored in memory on each storage system node in the network. A further aspect of the invention is a disk homeness application program interface (API), which provides commands that can be utilized by an administrator at a host computer to set, modify and disco play ownership information about each disk in the cluster. Upon a takeover, any node in the network can takeover one or more disks by reading the ownership information stored on the disks or in the tables.

Claims

1. A method for maintaining resource location information, comprising:

organizing a plurality of nodes as a cluster, wherein each node comprises a processor and a memory and each node is coupled to one or more resources;

maintaining, on each resource of the cluster, ownership information comprising a current owner identifying a node that currently serves data access requests directed to the resource and a home owner identifying an originally assigned node that serves the data access requests directed to the resource when the originally assigned node is operational; and

utilizing, by a takeover node, the ownership information to identify an identified resource, of the one or more resources, served by a failed node, the takeover node using the ownership information to perform a takeover of the identified resource, wherein the ownership information is updated with information from the takeover node.

2. The method of claim 1, further comprising storing the ownership information for each resource in a table at each node of the cluster.

3. The method of claim 1, further comprising in response to a failure of the failed node, generating a message to one or more nodes instructing the one or more nodes to read the ownership information of the identified resource when performing the takeover.

4. The method of claim 1, further comprising issuing commands at a remote management station to perform at least one of setting, modifying and displaying the ownership information.

5. The method of claim 1, wherein the home owner is the failed node and once the failed node is brought back into service, reassigning the home owner to service the data access requests for the identified resource.

6. The method of claim 1, wherein the ownership information is updated with information from the takeover node further comprising assigning the takeover node as the current owner.

7. A method for maintaining resource location information, comprising:

organizing a plurality of nodes as a cluster, wherein each node comprises a processor and a memory and each node is coupled to one or more resources;

maintaining, on each resource of the cluster, ownership information comprising a current owner identifying a node that currently serves data access requests directed to the resource and a home owner identifying an originally assigned node that serves the data access requests directed to the resource when the originally assigned node is operational; and

utilizing, by a takeover node, the ownership information to identify an identified resource, of the one or more resources, served by a failed node, wherein the takeover node uses the ownership information to perform a takeover of the identified resource.

8. The method of claim 7, further comprising storing the ownership information for each resource in a table at each node of the cluster.

9. The method of claim 7, further comprising in response to a failure of the failed node, generating a message to one or more nodes instructing the one or more nodes to read the ownership information of the identified resource when performing the takeover.

10. The method of claim 7, further comprising issuing commands at a remote management station to perform at least one of setting, modifying and displaying the ownership information.

11. The method of claim 7, wherein the home owner is the failed node and once the failed node is brought back into service, reassigning the home owner to service the data access requests for the identified resource.

12. The method of claim 7, further comprising updating, in response to the takeover, the ownership information for the identified resource to reflect the takeover node as being the current owner.

13. A storage network, comprising:

a plurality of storage system nodes organized as a cluster, wherein each node comprises a processor and a memory;

one or more resources coupled to each node wherein each of the one or more resources maintains ownership information comprising a current owner identifying a node that currently serves data access requests directed to the resource and a home owner identifying an originally assigned node that serves the data access requests directed to the resource when the originally assigned node is operational; and

a takeover node configured to read the ownership information to identify an identified resource, of the one or more resources, served by a failed node, the takeover node further configured to perform a takeover of the identified resource using the read ownership information.

14. The storage network of claim 13, further comprising a table at each node of the cluster to store the ownership information.

15. The storage network of claim 13, further comprising in response to a failure of the failed node, the failed node no longer sending a message to other nodes of the cluster.

16. The storage network of claim 13, further comprising a remote management station configured to issue commands to perform at least one of setting, modifying and displaying the ownership information.

17. The storage network of claim 13, wherein the home owner is the failed node and once the failed node is brought back into service, the home owner reassigned to service the data access requests for the identified resource.

18. The storage network of claim 13, wherein the ownership information for the identified resource is updated to reflect the takeover node as the current owner.