Installation guide

sync the cluster configuration file to all of the nodes, as described in Section 5.15, “ Propagating the

Configuration File to the Cluster Nodes” .

5.7.2. Configuring a Single St orage-Based Fence Device for a Node

When using non-power fencing methods (that is, SAN/storage fencing) to fence a node, you must

configure unfencing for the fence device. This ensures that a fenced node is not re-enabled until the

node has been rebooted. When you configure a device that requires unfencing, the cluster must first

be stopped and the full configuration including devices and unfencing must be added before the

cluster is started.

When you configure unfencing for a node, you specify a device that mirrors the corresponding fence

device you have configured for the node with the notable addition of the explicit action of o n or

enabl e.

For more information about unfencing a node, refer to the fence_no d e(8) man page.

Use the following procedure to configure a node with a single storage-based fence device that uses a

fence device named sanswitch1, which uses the fence_sanbox2 fencing agent.

1. Add a fence method for the node, providing a name for the fence method.

ccs -h host --addmethod method node

For example, to configure a fence method named SAN for the node nod e-0 1. exampl e. co m

in the configuration file on the cluster node nod e-0 1. example. co m, execute the following

command:

ccs -h node01.example.com --addmethod SAN node01.example.com

2. Add a fence instance for the method. You must specify the fence device to use for the node,

the node this instance applies to, the name of the method, and any options for this method

that are specific to this node:

ccs -h host --addfenceinst fencedevicename node method [options]

For example, to configure a fence instance in the configuration file on the cluster node nod e-

0 1. example. co m that uses the SAN switch power port 11 on the fence device named

sanswi tch1 to fence cluster node no d e-0 1. exampl e. co m using the method named SAN,

execute the following command:

ccs -h node01.example.com --addfenceinst sanswitch1

node01.example.com SAN port=11

3. To configure unfencing for the storage-based fence device on this node, execute the

following command:

ccs -h host --addunfence fencedevicename node action=on|off

You will need to add a fence method for each node in the cluster. The following commands configure

a fence method for each node with the method name SAN. The device for the fence method specifies

sanswi tch as the device name, which is a device previously configured with the --addfencedev

option, as described in Section 5.5, “ Configuring Fence Devices” . Each node is configured with a

⁠Chapt er 5. Configuring Red Hat Hig h Availabilit y Add- O n Wit h t he ccs Command