Explanation (250–350 words):
ONTAP clusters support amaximum of 24 nodesper cluster. In this scenario, the cluster already hassix nodesrunning mixed NAS (NFS) and SAN (FCP) workloads. When expanding an ONTAP cluster, NetApp best practices and installation rules strongly recommend adding nodesin HA pairsto maintain balanced high availability, performance symmetry, and consistent failover behavior.
Because nodes must be added in pairs, the cluster can scale from six nodes to eight, ten, twelve, and so on, up to the 24-node limit. However, the question is asking how many nodeswould be added, not the maximum supported. The standard NetApp expansion model for a six-node cluster is to addanother three HA pairs, which equalssix additional nodes, bringing the cluster to twelve nodes.
Adding only two or four nodes would result in uneven scaling and is not the standard recommended growth pattern for clusters of this size. Adding eighteen nodes would exceed practical expansion planning for a six-node system and approach the cluster maximum without justification.
Therefore, the correct answer is6.
