Installation guide

Note
It is recommended that you configure multiple fencing mechanisms for each node. A fencing
device can fail due to network split, a power outage, or a problem in the fencing device itself.
Configuring multiple fencing mechanisms can reduce the likelihood that the failure of a
fencing device will have fatal results.
This section documents the following procedures:
Section 5.7.1, “ Configuring a Single Power-Based Fence Device for a Node”
Section 5.7.2, “ Configuring a Single Storage-Based Fence Device for a Node”
Section 5.7.3, “ Configuring a Backup Fence Device”
Section 5.7.4, “ Configuring a Node with Redundant Power”
Section 5.7.6, “ Removing Fence Methods and Fence Instances”
5.7.1. Configuring a Single Power-Based Fence Device for a Node
Use the following procedure to configure a node with a single power-based fence device. The fence
device is named my_apc, which uses the fence_apc fencing agent. In this example, the device
named my_apc was previously configured with the --ad d fencedev option, as described in
Section 5.5, “ Configuring Fence Devices” .
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 AP C for the node no d e-0 1. example. 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 APC 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 power port 1 on the APC switch for the fence device named
my_apc to fence cluster node no d e-0 1. exampl e. co m using the method named AP C ,
execute the following command:
ccs -h node01.example.com --addfenceinst my_apc node01.example.com
APC port=1
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 APC . The device for the fence method specifies
my_apc as the device name, which is a device previously configured with the --ad d fenced ev
⁠Chapt er 5. Configuring Red Hat Hig h Availabilit y Add- O n Wit h t he ccs Command
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