Red Hat GFS 5.2.1 -, Administrator'S Manual

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108 Chapter 10. Using the Fencing System
Fending Method Fencing Agent
APC Network Power Switch
fence_apc
WTI Network Power Switch
fence_wti
Brocade FC Switch
fence_brocade
Vixel FC Switch
fence_vixel
HP RILOE
fence_rib
GNBD
fence_gnbd
Fence Notify GNBD
fence_notify_gnbd
Manual
fence_manual
Table 10-1. Fencing Methods and Agents
When a GFS cluster is operating, the fencing system executes those fencing agents. Specifically, when
using LOCK_GULM, the cluster manager is the master
lock_gulmd
daemon. The daemon uses the
fence_node
command to dispatch a fencing agent.
Note
Contact an authorized Red Hat support representative if there is a device you wish to use for fencing
that is not described in the following sections.
The following sections describe the fencing methods available with GFS.
10.2.1. APC MasterSwitch
APC MasterSwitch power switches are used to power cycle nodes that need to be fenced. The fenc-
ing agent,
fence_apc
, logs into the device and reboots the specific port for the failed node. The
fence_apc
fencing agent supports nodes with dual power supplies plugged into an APC Master-
Switch. Support for nodes with dual power supplies allows powering down both power supplies in a
node, thereby allowing fencing of nodes with dual power supplies. Refer to Section 6.7 Creating the
fence.ccs
File and Section 6.8 Creating the
nodes.ccs
File for information on how to configure
with this type of fencing.
Note
Lengthy Telnet connections to the APC should be avoided during the cluster operation. A fencing
operation trying to use the APC will be blocked until it can log in.
10.2.2. WTI Network Power Switch
WTI network power switches (NPSs) are used to power cycle nodes that need to be fenced. The
fencing agent,
fence_wti
, logs into the device and reboots the specific port for the offline node. The
fence_wti
fencing agent does not support nodes with dual power supplies plugged into a WTI NPS.
Refer to Section 6.7 Creating the
fence.ccs
File and Section 6.8 Creating the
nodes.ccs
File for
information on how to configure with this type of fencing.