STORAGE DEVICE FAILOVER

• US 20150121134A1
• Filed: 03/31/2014
• Published: 04/30/2015
• Est. Priority Date: 10/31/2013
• Status: Active Grant

• Current Assignee: Jpmorgan Chase Bank NA As The Agent
• Original Assignee: Fusion-IO Incorporated (Western Digital Corporation)
• Inventors: Wipfel, Robert, Van Assche, Bart, Gupta, Ranjan
• Granted Patent: US 9,766,992 B2
• Time in Patent Office: Days
• US Class Current: 714/6.31
• CPC Class Codes: G06F 11/1482 by means of middleware or OS functionality
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence

Abstract

Techniques are disclosed relating to storage device failover. In one embodiment, a plurality of storage devices are represented as cluster resources to a cluster resource manager that manages cluster resources on a plurality of cluster nodes. An indication may be received that a failover operation is requested with respect to one of the plurality of storage devices. In response to the indication, the cluster resource manager may initiate the failover operation. In some embodiments, the failover operation includes changing a first access state of the storage device and a second access state of another storage device. In such an embodiment, the storage device and the other storage device may be associated with a logical unit number. In some embodiments, the storage device is located within a first of the plurality of cluster nodes; the other storage device is located within a second of the plurality of cluster nodes.

Claims

1. A method, comprising:

representing a plurality of storage devices as cluster resources to a cluster resource manager that manages cluster resources on a plurality of cluster nodes;

receiving, at a resource agent, an indication that a failover operation is requested with respect to one of the plurality of storage devices; and

in response to the indication, the resource agent causing the cluster resource manager to initiate the failover operation.

2. The method of claim 1, wherein the failover operation includes changing a first access state of the storage device and a second access state of another storage device, wherein the storage device and the other storage device are associated with a logical unit number.

3. The method of claim 1, further comprising:

prior to an initialization of the cluster resource manager, receiving a request to perform a failover operation; and

denying the request in response to the cluster resource manager not being initialized.

4. The method of claim 1, wherein the resource agent enables the cluster resource manager to execute as a user-level application, and wherein the resource agent communicates with a system-level driver for one or more of the plurality of storage devices and communicates with the cluster resource manager.

5. The method of claim 1, wherein the causing includes adjusting one or more parameters for the cluster resources, wherein the one or more parameters are usable by the cluster resource manager to determine whether to fail over a cluster resource from one cluster node to another cluster node.

6. The method of claim 1, wherein the plurality of cluster nodes includes three or more cluster nodes, wherein the three or more cluster nodes include one or more storage devices within the plurality of storage devices.

7. An apparatus, comprising:

a management module configured to initialize a cluster resource manager configured to make a determination whether to fail over a cluster resource from a first cluster node to a second cluster node, wherein the cluster resource corresponds to a logical disk having a logical unit number;

a communication module configured to;

receive a first request to fail over the cluster resource; and

provide, while the cluster resource manager is being initialized, an indication that the first request cannot be processed.

8. The apparatus of claim 7, wherein the provided indication causes an initiator of the first request to resubmit a second, subsequent request to fail over the cluster resource.

9. The apparatus of claim 7, wherein the communication module is configured to:

determine that a shutdown associated with the cluster resource manager has been initiated; and

prevent processing requests to fail over cluster resources.

10. The apparatus of claim 9, wherein the communication module is configured to prevent processing the requests by closing a port used to receive requests to fail over cluster resources.

11. The apparatus of claim 7, further comprising:

an agent module is configured to communicate an indication of the determination to a small computer system interface (SCSI) core configured to manage one or more storage devices associated with the logical unit number.

12. The apparatus of claim 7, wherein the communication module is configured to:

receive a second request to fail over another cluster resource; and

provide an indication that the second request has been processed before the failover of the other cluster resource has been performed.

13. A non-transitory computer readable medium having program instructions stored thereon, wherein the program instructions are executable by a computing system to cause the computing system to perform operations comprising:

receiving a small computer system interface (SCSI) protocol request associated with a plurality of storage devices;

adjusting, based on the request, one or more parameters associated with a policy of the computing system, wherein the policy is used to determine a distribution of a plurality of resources across a plurality of computer systems; and

sending an indication of the determined distribution to one or more of the plurality of computer systems, wherein the indication is usable to perform a failover corresponding to a logical unit number of one of the plurality of storage devices.

14. The computer readable medium of claim 13, wherein the policy includes one or more rules specifying a relationship between storage devices within a first of the plurality of computer systems and storage devices in a second of the plurality of computer systems, and wherein the adjusting of the one or more parameters causes a change in the distribution according to the one or more rules.

15. The computer readable medium of claim 14, wherein the one or more parameters includes a first score of the first computing device, and wherein the distribution is determined responsive to the first score satisfying a threshold.

16. The computer readable medium of claim 13, wherein the received request is a set target port groups (STPG) command.

17. A non-transitory computer readable medium having program instructions stored thereon, wherein the program instructions are executable by a computing system of a cluster to cause the computing system to perform operations comprising:

receiving, at a kernel-level process, a request to change an access state associated with one or more storage devices; and

in response to the request, making, at a user-level cluster resource manager, a determination to fail over a cluster resource associated with the one or more storage device.

18. The computer readable medium of claim 17, wherein the operations further comprise:

conveying an indication of the determination to the kernel-level process, wherein the conveying is via a resource agent of the user-level cluster resource manager.

19. The computer readable medium of claim 17, wherein the cluster resource corresponds to a logical disk associated with the one or more storage devices.

20. The computer readable medium of claim 17, wherein the operations further comprise:

waiting to process requests to change access states until the kernel-level process and the user-level cluster resource manager are executing.