Managing HP Serviceguard for Linux, Seventh Edition, July 2007

Cluster and Package Maintenance
Reconfiguring a Cluster
Chapter 7256
Changing the Cluster Networking Configuration
while the Cluster Is Running
What You Can Do
Online operations you can perform include:
• Add a network interface and its HEARTBEAT_IP or STATIONARY_IP.
• Delete a network interface and its HEARTBEAT_IP or STATIONARY_IP.
• Change the designation of an existing interface from HEARTBEAT_IP
to STATIONARY_IP, or vice versa.
• Change the NETWORK_POLLING_INTERVAL.
• A combination of any of these in one transaction (cmapplyconf),
given the restrictions below.
What You Must Keep in Mind
The following restrictions apply:
• You must not change the configuration of all heartbeats at one time,
or change or delete the only configured heartbeat.
At least one working heartbeat must remain unchanged.
• You cannot add interfaces or modify their characteristics unless
those interfaces, and all other interfaces in the cluster configuration,
are healthy.
There must be no bad NICs or non-functional or locally switched
subnets in the configuration, unless you are deleting those
components in the same operation.
• You cannot change the designation of an existing interface from
HEARTBEAT_IP to STATIONARY_IP, or vice versa, without also making
the same change to all peer network interfaces on the same subnet
on all other nodes in the cluster.
• You cannot change the designation of an interface from
STATIONARY_IP to HEARTBEAT_IP unless the subnet is common to all
nodes.
Remember that the HEARTBEAT_IP must be on the same subnet on all
nodes, and must be an IPv4 address.