Using Serviceguard Extension for RAC, 10th Edition, April 2013

Figure 6 Eight-Node Cluster with EVA, XP or EMC Disk Array
FibreChannel switched configurations also are supported using either an arbitrated loop or fabric
login topology. For additional information about supported cluster configurations, refer to the HP
9000 Servers Configuration Guide, available through your HP representative.
Extended Distance Cluster Using Serviceguard Extension for RAC
Basic Serviceguard clusters are usually configured in a single data center, often in a single room,
to provide protection against failures in CPUs, interface cards, and software. Extended Serviceguard
clusters are specialized cluster configurations, which allow a single cluster to extend across two
or three separate data centers for increased disaster tolerance. Depending on the type of links
employed, distances of up to 100 km between data centers can be achieved.
Refer to Chapter 2 of the Understanding and Designing Serviceguard Disaster Tolerant Architectures
user’s guide, which discusses several types of extended distance cluster configurations that use
basic Serviceguard technology with software mirroring (using MirrorDisk/UX or CVM) and Fibre
Channel.
GMS Authorization
SGeRAC includes the Group Membership Service (GMS) authorization feature, which allows only
the listed users to access the GMS. By default, this feature is disabled. To enable this feature,
uncomment the variable GMS_USER[0] and add as many as users as you need.
Use the following steps to enable the GMS authorization (If Oracle RAC is already installed):
1. If Oracle RAC database instance and Oracle Clusterware are running, shut them down on
all nodes.
2. Halt the Serviceguard cluster.
3. Edit /etc/opt/nmapi/nmutils.conf to add all Oracle users on all nodes.
GMS_USER[0]=<oracle1>
GMS_USER[1]=<oracle2>
...
GMS_USER[n-1]=<oraclen>
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