Transparently migrating a storage object between nodes in a clustered storage system

• US 9,141,492 B2
• Filed: 05/15/2014
• Issued: 09/22/2015
• Est. Priority Date: 11/25/2009
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Dhavale, Poonam, Coatney, Susan M., Watanabe, Steven S.
• Primary Examiner(s): LU, KUEN S
• Application Number:
  US14/278,314
• Publication Number:
  US 20140317159A1
• Time in Patent Office: 495 Days
• Field of Search: 707/620
• US Class Current: 1/1
• CPC Class Codes: G06F 11/2005 using redundant communication controllers
• CPC Class Codes: G06F 11/2033 switching over of hardware resources
• CPC Class Codes: G06F 11/2046 where the redundant components share persistent storage G06F11/2043 takes precedence
• CPC Class Codes: G06F 11/2092 Techniques of failing over between control units
• CPC Class Codes: G06F 16/00 Information retrieval; Database structures therefor; File system structures therefor
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/119 Details of migration of file systems migration mechanisms in storage systems G06F3/0647
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: G06F 16/183 Provision of network file services by network file servers, e.g. by using NFS, CIFS network file access protocols H04L67/1097
• CPC Class Codes: G06F 16/185 Hierarchical storage management [HSM] systems, e.g. file migration or policies thereof details of archiving G06F16/11
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0647 Migration 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 7/00 Methods or arrangements for processing data by operating upon the order or content of the data handled logic circuits H03K19/00

Abstract

A storage object is migrated between nodes by a source node automatically verifying that another node is configured to service the storage object and changing ownership of the storage object based on the verifying. A cluster manager for the clustered storage system receives a request and provides the request to the source which owns the storage object. The source verifies that the destination is configured according to a predetermined configuration for servicing the storage object. Based on the verifying, the source offlines the storage object and updates ownership information of the storage object, thereafter allowing the destination to online the storage object. The cluster manager further provides the updated ownership information to all the nodes in the cluster, so an access request intended for the storage object may be received by any node and forwarded to the destination using the updated ownership information to effect a transparent migration.

Claims

1. A method comprising:

in response to receipt of a request to change request servicing for a logical organization of a plurality of storage objects from a first node to a second node,

determining that the second node can service requests that target the logical organization based, at least in part, on configuration data of the second node,

wherein determining that the second node can service requests that target the logical organization comprises determining a software version indicated in the configuration data of the second node;

halting servicing by the first node of client requests that target the logical organization after said determining that the second node can service requests that target the logical organization;

changing data about the logical organization from indicating the first node to indicating the second node; and

communicating to a clustered storage system that the second node services client requests that target the logical organization,

wherein the clustered storage system includes the first node and the second node.

2. The method of claim 1 further comprising receiving, from a managing node of the clustered storage system, the request to change request servicing for the logical organization from the first node to the second node.

3. The method of claim 1 further comprising:

determining that specified operations are not being performed on the logical organization, wherein said halting servicing by the first node of client requests that target the logical organization occurs after said determining that the specified operations are not being performed on the logical organization.

4. The method of claim 3, wherein the specified operations include at least one of a fault tolerance operation, a maintenance operation, or an access request servicing operation.

5. The method of claim 1, wherein said determining that the second node can service requests that target the logical organization based, at least in part, on configuration data of the second node comprises the first node querying the second node as to the configuration data and determining whether the configuration data of the second node satisfies one or more configuration criteria.

6. The method of claim 1, wherein said determining that the second node can service requests that target the logical organization further comprises at least one of determining whether the configuration data of the second node indicates that the second node is configured to service storage requests, determining whether the configuration data of the second node indicates an operating mode that allows the second node to service storage requests, and determining a storage limit indicated in the configuration data of the second node.

7. The method of claim 1, wherein said communicating to the clustered storage system that the second node services client requests that target the logical organization comprises:

the second node communicating to a managing node that request servicing for the logical organization has changed to the second node; and

the managing node communicating to nodes of the clustered storage system that request servicing for the logical organization has changed to the second node.

8. One or more computer readable storage media having machine executable program instructions stored thereon, the machine executable program instructions comprising program instructions to:

in response to receipt of a request to change request servicing for a logical organization of a plurality of storage objects from a first node to a second node,

determine whether the second node can service requests that target the logical organization based, at least in part, on configuration data of the second node,

wherein the program instructions to determine whether the second node can service requests that target the logical organization comprises program instructions to determine a software version indicated in the configuration data of the second node;

halt servicing by the first node of client requests that target the logical organization after a determination that the second node can service requests that target the logical organization;

change data about the logical organization from indicating the first node to indicating the second node; and

communicate to a clustered storage system that the second node services client requests that target the logical organization, wherein the clustered storage system includes the first node and the second node.

9. The one or more computer readable storage media of claim 8, wherein the program instructions to halt servicing by the first node of client requests that target the logical organization comprise program instructions to store, by the first node, client requests targeting the logical organization until after the data about the logical organization is changed to indicate the second node instead of the first node.

10. The one or more computer readable storage media of claim 9, wherein the program instructions further comprise program instructions to communicate to the second node client requests stored while servicing, by the first node, of client requests that target the logical organization were halted.

11. The one or more computer readable storage media of claim 10, wherein the program instructions to communicate to the second node the client requests stored while servicing, by the first node, of client requests that target the logical organization were halted comprise program instructions to communicate the stored client requests to the second node in response to an update to locally stored information, wherein the update indicates that the second node services client requests targeting the logical organization.

12. The one or more computer readable storage media of claim 8, wherein the wherein the program instructions to halt servicing by the first node of client requests that target the logical organization comprise program instructions to respond to client requests that target the logical organization with an indication of an error.

13. The one or more computer readable storage media of claim 8, wherein the program instructions further comprise program instructions to:

determine that specified operations are not being performed on the logical organization, wherein halting servicing by the first node of client requests that target the logical organization occurs after a determination that the specified operations are not being performed on the logical organization.

14. The one or more computer readable storage media of claim 13, wherein the specified operations include at least one of a fault tolerance operation, a maintenance operation, or an access request servicing operation.

15. The one or more computer readable storage media of claim 8, wherein the program instructions to determine that the second node can service requests that target the logical organization based, at least in part, on configuration data of the second node comprises program instructions to query the second node as to the configuration data and determine whether the configuration data of the second node satisfies one or more configuration criteria.

16. The one or more computer readable storage media of claim 8, wherein the program instructions to determine whether the second node can service requests that target the logical organization further comprise program instructions to, at least one of, determine whether the configuration data of the second node indicates that the second node is configured to service storage requests, determine whether the configuration data of the second node indicates an operating mode that allows the second node to service storage requests, and determine a storage limit indicated in the configuration data of the second node.

17. An apparatus comprising:

a processor;

a network interface; and

a machine readable storage medium having program instructions stored therein, the program instructions executable by the processor to cause the apparatus to,

in response to receipt of a request to change request servicing for a logical organization of a plurality of storage objects from the apparatus to a different apparatus,

determine whether the different apparatus can service requests that target the logical organization based, at least in part, on configuration data of the different apparatus,

wherein the program instructions to determine whether the different apparatus can service requests that target the logical organization comprises program instructions to determine a software version indicated in the configuration data of the different apparatus;

halt servicing by the apparatus of client requests that target the logical organization after a determination that the different apparatus can service requests that target the logical organization;

change data about the logical organization from indicating the apparatus to indicating the different apparatus; and

communicate to a clustered storage system that the different apparatus services client requests that target the logical organization, wherein the clustered storage system includes the apparatus and the different apparatus.

18. The apparatus of claim 17, wherein the program instructions executable by the processor to cause the apparatus to halt servicing by the apparatus of client requests that target the logical organization comprise program instructions to store client requests targeting the logical organization until after the data about the logical organization is changed to indicate the different apparatus instead of the apparatus.

19. The apparatus of claim 18, wherein the program instructions further comprise program instructions executable by the processor to cause the apparatus to communicate to the different apparatus client requests stored while servicing, by the apparatus, of client requests that target the logical organization were halted.

20. The apparatus of claim 19, wherein the program instructions executable by the processor to cause the apparatus to communicate to the different apparatus the client requests stored while servicing, by the first apparatus, of client requests that target the logical organization were halted comprise program instructions executable by the processor to cause the apparatus to communicate the stored client requests to the different apparatus in response to an update to locally stored information, wherein the update indicates that the different apparatus services client requests targeting the logical organization.