When your Oracle SuperCluster M8 or Oracle SuperCluster M7 was first installed, the NTP service was configured and enabled in the global zone. Only one NTP daemon can run on one system. So if you have a system with a combination of global and nonglobal zones, only one NTP can run across those global and nonglobal zones.
When you create zones on Database Domains, the NTP service within the zones on the Database Domains will be disabled automatically by the zone configuration scripts, and they must be left disabled. The zone configuration scripts also ensure that the Cluster Time Synchronization Services daemon (ctssd) will only run in observer mode once the database software is installed and configured.