Red Hat GFS 6.0 -, Administrator'S Manual

Page: 130 / 192

116 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
McData FC Switch
fence_mcdata
Vixel FC Switch
fence_vixel
HP RILOE
fence_rib
GNBD
fence_gnbd
xCAT
fence_xcat
Manual
fence_manual
Table 10-1. Fencing Methods and Agents
Warning
Manual fencing should not be used in a production environment. Manual fencing depends on human
intervention whenever a node needs recovery. Cluster operation is halted during the intervention.
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
fencing 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 MasterSwitch. 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 6.6 Creating the
fence.ccs
File and Section 6.7 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.