How is configuration maintained across nodes in a cluster?

The correct answer is that configuration is maintained across nodes in a cluster by maintaining a replicated database (RDB) on each cluster node. The RDB is integral to NetApp's clustered Data ONTAP architecture, allowing consistent configuration and state information to be shared across the nodes in the cluster.

In this distributed database system, certain configurations and settings are automatically synchronized among the nodes, ensuring that any changes are reflected universally across the cluster. This is essential for maintaining operational coherence and providing high availability. As a result, even if one node fails or is taken offline for maintenance, the configuration and operational state of the cluster continue seamlessly because all nodes have access to the replicated data.

The other options do not provide the same level of reliability and efficiency in configuration management as the RDB. Manual synchronization can lead to errors and inconsistencies, while automated scripts might require additional maintenance and oversight. A central management server could present a single point of failure and might complicate scalability. Thus, the use of an RDB is the most effective method for maintaining configuration across nodes in a cluster.