Installation guide

<clusternode name="node-03.example.com" nodeid="3">
<fence>
<method name="APC-dual">
<device name="apc1" port="3"action="off"/>
<device name="apc2" port="3"action="off"/>
<device name="apc1" port="3"action="on"/>
<device name="apc2" port="3"action="on"/>
</method>
</fence>
</clusternode>
</clusternodes>
<fencedevices>
<fencedevice agent="fence_apc" ipaddr="apc_ip_example"
login="login_example" name="apc1" passwd="password_example"/>
<fencedevice agent="fence_apc" ipaddr="apc_ip_example"
login="login_example" name="apc2" passwd="password_example"/>
</fencedevices>
<rm>
</rm>
</cluster>
When using power switches to fence nodes with dual power supplies, the agents must be told to
turn off both power ports before restoring power to either port. The default off-on behavior of the
agent could result in the power never being fully disabled to the node.
7.4 . Configuring Failover Domains
A failover domain is a named subset of cluster nodes that are eligible to run a cluster service in the
event of a node failure. A failover domain can have the following characteristics:
Unrestricted — Allows you to specify that a subset of members are preferred, but that a cluster
service assigned to this domain can run on any available member.
Restricted — Allows you to restrict the members that can run a particular cluster service. If none of
the members in a restricted failover domain are available, the cluster service cannot be started
(either manually or by the cluster software).
Unordered — When a cluster service is assigned to an unordered failover domain, the member on
which the cluster service runs is chosen from the available failover domain members with no
priority ordering.
Ordered — Allows you to specify a preference order among the members of a failover domain.
Ordered failover domains select the node with the lowest priority number first. That is, the node in
a failover domain with a priority number of "1" specifies the highest priority, and therefore is the
most preferred node in a failover domain. After that node, the next preferred node would be the
node with the next highest priority number, and so on.
Failback — Allows you to specify whether a service in the failover domain should fail back to the
node that it was originally running on before that node failed. Configuring this characteristic is
useful in circumstances where a node repeatedly fails and is part of an ordered failover domain.
In that circumstance, if a node is the preferred node in a failover domain, it is possible for a
service to fail over and fail back repeatedly between the preferred node and another node,
causing severe impact on performance.
Fencin g Configurat ion Examples
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