Install guide

<?xml version="1.0"?>

<fence_daemon post_fail_delay="0" post_join_delay="3"/>

<quorumd interval="7" device="/dev/m apper/qdisk" tko="9" votes="3"

log_level="5"/>

Tip

You may need to change the maximum journal size for a partition. T he following procedure

provides an example of changing the maximum journal size of an existing partition to 400MB.

tune2fs -l /dev/mapper/vg1-oracle |grep -i "journal inode"

debugfs -R "stat <8>" /dev/mapper/vg1-oracle 2>&1 | awk '/Size: /{print $6}

tune2fs -O ^has_journal /dev/mapper/vg1-oracle

tune2fs -J size=400 /dev/mapper/vg1-oracle

Warning

Fencing in two-node clusters is more prone to fence and quorum race conditions than fencing in

clusters with three or more nodes. If node 1 can no longer communicate with node 2, then which

node is actually the odd man out? Most of these races are resolved by the quorum disk, which is

why it is important for the HA case, and mandatory for RAC/GFS.

RAC/GFS Requirement

Red Hat Cluster Suite must be implemented with qdisk, or the configuration is unsupported. Red

Hat Cluster Suite has to retain quorum to support a single, surviving RAC node. T his single-node

operation is required for certified combinations of RAC/GFS.

3.3. Network Topology

A cluster’s network is either complicated, or really complicated. T he basic cluster involves several sets

of logical network pathways. Some of these share physical interfaces, and some require dedicated

physical interfaces and VLANs, depending on the degree of robustness required. T his example is based

on a topology that Red Hat uses to certify Oracle RAC/GFS, but is also suitable for the HA configuration.

Tip

Cluster networks require several VLANs and multiple address assignments across those VLANs.

If bonds are going to span VLANs or switches, then it might be required to use ARP to ensure the

correct behavior in the event of a link failure.

3.3.1. Public Network

Chapter 3. Software Installation and Configuration