Managing Serviceguard Seventeenth Edition, First Reprint December 2009

• Two heartbeat subnets; or
• One heartbeat subnet with a standby; or
• One heartbeat subnet using APA with two
physical ports in hot standby mode or LAN
monitor mode.
You cannot configure more than one heartbeat
IP address on an interface; only one
HEARTBEAT_IP is allowed for each
NETWORK_INTERFACE.
NOTE: The Serviceguard cmapplyconf,
cmcheckconf, and cmquerycl commands
check that these minimum requirements are met,
and produce a warning if they are not met at the
immediate network level. If you see this warning,
you need to check that the requirements are met
in your overall network configuration.
If you are using virtual machine guests as nodes,
you have a valid configuration (and can ignore
the warning) if there is one heartbeat network
on the guest, backed by a network on the host
using APA with two trunk members (HPVM),
or using NIC bonding in high availability mode
(or mode 1) with two slaves (VMware ESX
Server).
For information about changing the configuration
online, see “Changing the Cluster Networking
Configuration while the Cluster Is Running”
(page 332).
Considerations for cross-subnet:
IP addresses for a given heartbeat path are
usually on the same subnet on each node, but it
is possible to configure the heartbeat on multiple
subnets such that the heartbeat is carried on one
subnet for one set of nodes and another subnet
for others, with the subnets joined by a router.
This is called a cross-subnet configuration, and
in this case at least two heartbeat paths must be
configured for each cluster node. In addition,
each heartbeat subnet on each node must be
physically routed separately to the heartbeat
Cluster Configuration Planning 149