Managing HP Serviceguard for Linux Ninth Edition, April 2009

• Change IP Monitor parameters: SUBNET, IP_MONITOR, POLLING TARGET; see
the entries for these parameters under“Cluster Configuration Parameters ”
(page 100) 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 32)).
• 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 204).
• 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.
248 Cluster and Package Maintenance