Red Hat CLUSTER SUITE FOR ENTERPRISE LINUX 5.2 Overview page 17

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fencing device. The fencing program makes a call to a fencing agent specified in the cluster

configuration file. The fencing agent, in turn, fences the node via a fencing device. When

fencing is complete, the fencing program notifies the cluster manager.

Red Hat Cluster Suite provides a variety of fencing methods:

• Power fencing — A fencing method that uses a power controller to power off an inoperable

node.

• Fibre Channel switch fencing — A fencing method that disables the Fibre Channel port that

connects storage to an inoperable node.

• GNBD fencing — A fencing method that disables an inoperable node's access to a GNBD

server.

• Other fencing — Several other fencing methods that disable I/O or power of an inoperable

node, including IBM Bladecenters, PAP, DRAC/MC, HP ILO, IPMI, IBM RSA II, and others.

Figure 1.3, "Power Fencing Example"

fencing program in node A causes the power controller to power off node D.

Channel Switch Fencing Example"

example, the fencing program in node A causes the Fibre Channel switch to disable the port for

node D, disconnecting node D from storage.

shows an example of power fencing. In the example, the

shows an example of Fibre Channel switch fencing. In the

Fencing

Figure 1.4, "Fibre

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