Red Hat Enterprise Linux 5 Cluster Suite Overview page 15

Fencing
Figure 1.4. Fibre Channel Switch Fencing Example
Specifying a fencing method consists of editing a cluster configuration file to assign a fencing-method
name, the fencing agent, and the fencing device for each node in the cluster.
The way in which a fencing method is specified depends on if a node has either dual power supplies
or multiple paths to storage. If a node has dual power supplies, then the fencing method for the
node must specify at least two fencing devices — one fencing device for each power supply (refer
Figure 1.5, "Fencing a Node with Dual Power Supplies"). Similarly, if a node has multiple paths to
to
Fibre Channel storage, then the fencing method for the node must specify one fencing device for each
path to Fibre Channel storage. For example, if a node has two paths to Fibre Channel storage, the
fencing method should specify two fencing devices — one for each path to Fibre Channel storage
Figure 1.6, "Fencing a Node with Dual Fibre Channel Connections").
(refer to
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