2.5. Fencing Topology

Fencing is one of the most important features of Red Hat Cluster Suite HA. Fencing is ultimately responsible for guaranteeing the integrity of the cluster and preventing wholesale corruption of an Oracle database.

Red Hat Cluster Suite HA supports a variety of fencing technologies, but we recommend the use of fencing agents that manage the power to the server nodes. This is performed using either the server’s Baseboard Management Controller (BMC), or with external Power Distribution Units (PDUs). Most IPMI-based BMCs, as well as a few popular PDUs are supported.

In this sample cluster, the nodes are HP Proliants, and the IPMI-based BMC is call iLO (Integrated Lights-Out Management).

For the certified Oracle RAC configurations, Oracle Clusterware does not support power-managed fencing and must be configured so as to not interfere with Red Hat Cluster Suite HA fencing agents.