Managing Serviceguard Fifteenth Edition, reprinted May 2008

Building an HA Cluster Configuration
Configuring the Cluster
Chapter 5236
IMPORTANT Note that in this example subnet 15.244.65.0, used by NodeA and
NodeB, is not routed to 15.244.56.0, used by NodeC and NodeD.
But subnets 15.13.164.0 and 15.13.165.0, used by NodeA and NodeB,
are routed respectively to subnets 15.13.172.0 and15.13.182.0, used
by NodeC and NodeD. At least one such routing among all the nodes must
exist for cmquerycl to succeed.
For information about configuring the heartbeat in a cross-subnet
configuration, see the HEARTBEAT_IP parameter discussion under
“Cluster Configuration Parameters” starting on page 156.
Identifying Heartbeat Subnets
The cluster configuration file includes entries for IP addresses on the
heartbeat subnet. HP recommends that you use a dedicated heartbeat
subnet, and configure heartbeat on other subnets as well, including the
data subnet.
The heartbeat must be on an IPv4 subnet and must employ IPv4
addresses. An IPv6 heartbeat is not supported.
The heartbeat can comprise multiple subnets joined by a router. In this
case at least two heartbeat paths must be configured for each cluster
node. See also the discussion of HEARTBEAT_IP under “Cluster
Configuration Parameters” starting on page 156, and “Cross-Subnet
Configurations” on page 41.
NOTE If you are using CVM Version 3.5 disk groups, you can configure only a
single heartbeat subnet, which should be a dedicated subnet. Each
system on this subnet must have standby LANs configured, to ensure
that there is a highly available heartbeat path.
Versions 4.1 and later allow multiple heartbeats, and require that you
configure either multiple heartbeats or a single heartbeat with a
standby.