Install guide

zones to regulate the use of the array. It is recommended that the all the FCP ports from the servers be

isolated into a zone with the access ports (or HCAs) on the storage array. Although many customers

use large storage arrays and then sub-divide their use amongst many consumers in the datacenter, we

would not recommend this for Oracle clusters. Production Oracle databases tend to place great

demands on storage arrays, and sharing them will only complicate the deployment. And complication

always means a reduction in reliability.

In the iSCSI case, bonded NICs can be used in lieu of DM-multipath, but should be a separate set of

NICs that will be used for the Red Hat Cluster Suite heartbeat service, or Oracle RAC Clusterware

services.

1.5. 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. T his 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.

1.6. Network Topology Overview

Up to three sets of network pathways are needed for an Oracle HA cluster to operate properly:

The application tier, on behalf of users, must have access to the database nodes.

The Red Hat Cluster Suite node monitoring services need access to all nodes to determine the state

of the cluster.

In the RAC case, Oracle Clusterware needs a high-speed pathway to implement Oracle Cache

Fusion (or Global Cache Services – GCS).

Oracle RAC was certified with GCS running over bonded pairs of Ethernet interfaces, as was the Red

Hat Cluster Suite heartbeat service to ensure coordinated cluster activity. It is optional to use bonded

links for the Red Hat Cluster Suite heartbeat (or Oracle Clusterware GCS), but is highly recommended.

Chapter 1. Overview