Synchronization – The primary requirement when you configure NTP, or any time synchronization facility within the cluster, is that all cluster nodes must be synchronized to the same time.
Accuracy – Consider accuracy of time on individual nodes to be of secondary importance to the synchronization of time among nodes. You are free to configure NTP as best meets your individual needs if this basic requirement for synchronization is met.
Error messages about nonexistent nodes – Unless you have installed your own /etc/inet/ntp.conf file, the scinstall command installs a default ntp.conf file for you. The default file is shipped with references to the maximum number of nodes. Therefore, the xntpd(1M) daemon might issue error messages regarding some of these references at boot time. You can safely ignore these messages. See How to Configure Network Time Protocol (NTP) for information about how to suppress these messages under otherwise normal cluster conditions.
See the Sun Cluster Concepts Guide for Solaris OS for further information about cluster time. See the /etc/inet/ntp.cluster template file for additional guidelines about how to configure NTP for a Sun Cluster configuration.