Managing Serviceguard 13th Edition, February 2007

Building an HA Cluster Configuration
Configuring the Cluster
Chapter 5 225
Identifying Heartbeat Subnets
The cluster ASCII file includes entries for IP addresses on the heartbeat
subnet. It is recommended that you use a dedicated heartbeat subnet,
but it is possible to configure heartbeat on other subnets as well,
including the data subnet.
The heartbeat must be on an IPv4 subnet and must employ IPv4
addresses. IPv6 heartbeat is not supported.
NOTE If you are using Version 3.5 VERITAS CVM 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. (Version 4.1
configurations can have multiple heartbeats.) CVM is not supported on
all systems; see “About VERITAS CFS and CVM” on page 27.
Specifying Maximum Number of Configured Packages
This specifies the most packages that can be configured in the cluster.
The parameter value must be equal to or greater than the number of
packages currently configured in the cluster. The count includes all types
of packages: failover, multi-node, and system multi-node.
For Serviceguard A.11.17, the default is 150, which is the maximum
allowable number of all packages per cluster.
NOTE Remember to tune HP-UX kernel parameters on each node to ensure
that they are set high enough for the largest number of packages that
will ever run concurrently on that node.
Modifying Cluster Timing Parameters
The cmquerycl command supplies default cluster timing parameters for
HEARTBEAT_INTERVAL and NODE_TIMEOUT. Changing these parameters
will directly affect the cluster’s reformation and failover times. It is
useful to modify these parameters if the cluster is reforming occasionally
because of heavy system load or heavy network traffic.