Sun Cluster 3.1 software can only provide service for those data services that are either supplied with the Sun Cluster product or set up with the Sun Cluster data services API.
Sun Cluster software currently does not have an HA Data Service for the sendmail(1M) subsystem. It is permitted to run sendmail on the individual cluster nodes, but the sendmail functionality will not be highly available, including the functionality of mail delivery and mail routing, queuing, or retry.
Do not configure cluster nodes as routers (gateways). If the system goes down, the clients cannot find an alternate router and cannot recover.
Do not configure cluster nodes as NIS or NIS+ servers. However, cluster nodes can be NIS or NIS+ clients.
Do not use a Sun Cluster configuration to provide a highly available boot or install service on client systems.
Do not use a Sun Cluster 3.1 configuration to provide an rarpd service.