Backup Groups

Backup groups are sets of network adapters that provide redundant connections between a single cluster node and the public network. You configure backup groups during initial installation by using the scinstall(1M) command, or after initial installation by using the pnmset(1M) command. PNM allows you to configure as many redundant adapters as you want on a single host.

To configure backup groups initially, you run pnmset(1M) as root before the cluster is started. The command runs as an interactive script to configure and verify backup groups. It also selects one adapter to be used as the primary, or active, adapter. The pnmset(1M) command names backup groups nafon, where n is an integer you assign. The command stores backup group information in the /etc/pnmconfig file.

To change an existing PNM configuration on a cluster node, you must remove the node from the cluster and then run the pnmset(1M) command. PNM monitors and incorporates changes in backup group membership dynamically.

The /etc/pnmconfig file is not removed even if the SUNWpnm package is removed, for example, during a software upgrade. That is, the backup group membership information is preserved during software upgrades and you are not required to run the pnmset(1M) utility again, unless you want to modify backup group membership.