Managing HP Serviceguard A.11.20.00 for Linux, June 2012

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 a HEARTBEAT_IP or STATIONARY_IP interface from IPv4 to IPv6, or vice versa.
• Change the designation of an existing interface from HEARTBEAT_IP to STATIONARY_IP,
or vice versa.
• Change the NETWORK_POLLING_INTERVAL.
• Change IP Monitor parameters: SUBNET, IP_MONITOR, POLLING TARGET; see the entries
for these parameters under“Cluster Configuration Parameters ” (page 80) for more information.
• 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.
Similarly, you cannot change an interface from IPv4 to IPv6 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 an IPv4 address, and must be on the same subnet
on all nodes, except in cross-subnet configurations; see “Cross-Subnet Configurations”
(page 23)).
• You cannot delete a subnet or IP address from a node while a package that uses it (as a
monitored_subnet, ip_subnet, or ip_address) is configured to run on that node.
Information about these parameters begins at monitored_subnet (page 164).
• You cannot change the IP configuration of an interface (NIC) used by the cluster in a single
transaction (cmapplyconf).
You must first delete the NIC from the cluster configuration, then reconfigure the NIC (using
ifconfig, for example), then add the NIC back into the cluster.
Reconfiguring a Cluster 207