HP Serviceguard manual What You Must Keep in Mind

•Change IP Monitor parameters: SUBNET, IP_MONITOR, POLLING TARGET; see the entries for these parameters under “Cluster Configuration Parameters ” (page 109) 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, preferably with a standby, must remain unchanged.

•In a CVM configuration, you can add and delete only data LANs and IP addresses. You cannot change the heartbeat configuration while a cluster that uses CVM is running.

•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 on the same subnet on all nodes, except in cross-subnet configurations; see “Cross-Subnet Configurations” (page 30).

•You cannot delete a primary interface without also deleting any standby interfaces, unless the standby is being used by another primary interface that is not being deleted.

•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.

See the package networking parameter descriptions (page 241) for more information.

•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 (1m), for example), then add the NIC back into the cluster.

Examples of when you must do this include:

◦moving a NIC from one subnet to another

◦adding an IP address to a NIC

◦removing an IP address from a NIC

CAUTION: Do not add IP addresses to network interfaces that are configured into the Serviceguard cluster, unless those IP addresses themselves will be immediately configured into the cluster as stationary IP addresses. If you configure any address other than a stationary IP address on a Serviceguard network interface, it could collide with a relocatable package address assigned by Serviceguard.

Some sample procedures follow.

298 Cluster and Package Maintenance