1.5.9 Public Network Management (PNM)

Some types of failures cause all logical hosts residing on that node, to be transferred to another node. The failure of a network adapter card, connector or cable between the node and the public network need not result in a node failover. Public Network Management (PNM) software in the Sun Cluster framework allows network adapters to be grouped into sets such that if one fails, another in its group takes over the servicing of network requests. A user will experience only a small delay while the error detection and failover mechanisms are in process.

In a configuration using PNM, there are multiple network interfaces on the same subnet. These interfaces make up a backup group. At any point, a network adapter can only be in one backup group and only one adapter within a backup group is active. When the current active adapter fails, the PNM software automatically switches the network services to use another adapter in the backup group. All adapters used for public networks should be in a backup group.

Backup groups are also used to monitor the public nets even when same-node failover adapters are not present.

Figure 1-21 Network Adapter Failover Configuration

Refer to the Sun Cluster 2.2 System Administration Guide for information on setting up and administering PNM.