Method and system for transparently replacing nodes of a clustered storage system

• US 9,378,258 B2
• Filed: 08/07/2013
• Issued: 06/28/2016
• Est. Priority Date: 11/25/2009
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Dhavale, Poonam P., Strange, Stephen H.
• Primary Examiner(s): SCHELL, JOSEPH O
• Application Number:
  US13/961,086
• Publication Number:
  US 20150046745A1
• Time in Patent Office: 1,056 Days
• 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

Method and system for replacing a first node and a second of a clustered storage system by a third node and a fourth node are provided. The method includes migrating all storage objects managed by the first node to the second node; replacing the first node by the third node and migrating all the storage objects managed by the first node and the second node to the third node; and replacing the second node by the fourth node and then migrating the storage objects previously managed by the second node but currently managed by the third node to the fourth node. The nodes may also be replaced by operationally connecting the third node and the fourth node to storage managed by the first node and the second node; joining the third node and the fourth node to a same cluster as the first node and the second node.

Claims

1. A method comprising:

non-disruptively migrating, by a storage computing device, storage objects managed by a first node to a second node;

replacing, by the storage computing device, the first node by a third node;

migrating, by the storage computing device, the storage objects from the second node to the third node;

replacing, by the storage computing device, the second node by a fourth node; and

migrating, by the storage computing device, the storage objects from the third node to the fourth node, wherein access to data previously managed by the first node and the second node is available while the first node and the second node are being replaced.

2. The method of claim 1, wherein the first node and the second node are configured as a failover pair, wherein when one of the nodes fails, a remaining operational node in the failover pair takes over storage objects managed by the failed node.

3. The method of claim 2, wherein a failover mode between the first node and the second node is disabled until the third node and the fourth node become operational.

4. The method of claim 1, wherein the first node and the second node are configured to view storage objects that are managed by each other.

5. The method of claim 1, wherein the replacing the first node by the third node comprises upgrading a storage operating system version in the third node.

6. The method of claim 1, wherein the replacing the first node by the third node comprises upgrading hardware.

7. The method of claim 1, wherein the storage objects are part of an aggregate.

8. A non-transitory machine readable medium having stored thereon instructions for performing a method, the medium comprising machine executable code which when executed by at least one machine, causes the machine to:

non-disruptively migrate storage objects managed by a first node to a second node;

replace the first node by a third node;

migrate the storage objects from the second node to the third node;

replace the second node by a fourth node; and

migrate the storage objects to the fourth node, wherein access to data previously managed by the first node and the second node is available while the first node and the second node are being replaced.

9. The medium of claim 8, wherein the first node and the second node are configured as a failover pair, wherein when one of the nodes fails, a remaining operational node in the failover pair takes over storage objects managed by the failed node.

10. The medium of claim 9, wherein a failover mode between the first node and the second node is disabled until the third node and the fourth node become operational.

11. The medium of claim 8, wherein the first node and the second node are configured to view storage objects that are managed by each other.

12. The medium of claim 8, wherein the replacing the first node by the third node comprises upgrading a storage operating system version in the third node.

13. The medium of claim 8, wherein the replacing the first node by the third node comprises upgrading hardware.

14. The medium of claim 8, wherein the storage objects are part of an aggregate.

15. A computing device comprising:

a memory containing a machine readable medium comprising machine executable code having stored thereon instructions for performing a method of controller replacement;

a processor coupled to the memory, the processor configured to execute the machine executable code to cause the processor to;

non-disruptively migrate storage objects managed by a first node to a second node;

replace the first node by a third node;

migrate the storage objects to the third node;

simultaneously storage objects managed by the first node are non-disruptively migrated to the third node and the second node is replaced by a fourth node; and

migrate the storage objects from the third node to the fourth node, wherein access to data previously managed by the first node and the second node is available while the first node and the second node are being replaced.

16. The device of claim 15, wherein the first node and the second node are configured as a failover pair, wherein when one of the nodes fails, a remaining operational node in the failover pair takes over storage objects managed by the failed node.

17. The device of claim 15, wherein the first node and the second node are configured to view storage objects that are managed by each other.

18. The device of claim 15, wherein the replacing the first node by the third node comprises upgrading a storage operating system version or upgrading hardware in the third node.

19. The device of claim 15, wherein a failover mode between the first node and the second node is disabled until the third node and the fourth node become operational.

20. The device of claim 15, wherein replacing the storage objects are part of an aggregate.