Red Hat GFS 5.2.1 -, Administrator'S Manual

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110 Chapter 10. Using the Fencing System
10.2.5. HP RILOE Card
A GFS node that has an HP RILOE (Remote Insight Lights-Out Edition) card can be fenced with
the
fence_rib
fencing agent. 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
The
fence_rib
fencing agent requires the
Stunnel
software be installed on the system running the
fencing agent. Stunnel is required to connect to the HP RILOE card.
10.2.6. GNBD
Nodes that only use GFS with storage devices via GNBD (Global Network Block Device) servers
can use the
fence_gnbd
agent. The agent requires no special hardware. The
fence_gnbd
fencing
agent instructs all GNBD servers to disallow all I/O from a fenced node. When a fenced node is reset
and re-imports the GNBD devices, the GNBD servers again allow the node access to the devices.
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
If you are using GNBD multipath, you must not specify the GNBD fencing agent (
fence_gnbd
) as a
fencing device for GNBD server nodes (nodes that export GNBDs to GFS nodes).
10.2.7. Fence Notify GNBD
When using GNBD multipath, GNBD server nodes (nodes that export GNBDs to GFS nodes) must be
fenced with a fencing method that physically removes the nodes from the network and notifies GFS
nodes that a GNBD server has been fenced. The fencing method used for GNBD server nodes must
include a fencing device that uses the
fence_notify_gnbd
fencing agent for notifying GFS nodes
that a GNBD server has been fenced. The
fence_notify_gnbd
fencing agent provides GFS nodes
with the IP address or hostname of the GNBD server node that has been fenced. 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.
10.2.8. Manual
In the absence of fencing hardware, a manual fencing method can be used for testing or evaluation
purposes.
Caution
Manual fencing depends on human intervention whenever a node needs recovery. Cluster operation
is halted during the intervention; therefore, manual fencing is not recommended for production use.