The following rules apply to dual-string configurations that use mediators.
Disk sets must be configured with either two or three mediator hosts. Two of these mediator hosts must be the same two cluster nodes that are used for the disk set. The third can be another node in the cluster or a non-clustered host on the cluster's public network, such as a quorum server.
Mediators cannot be configured for disk sets that do not meet the two-string and two-host criteria.
These rules do not require that the entire cluster consist of only two nodes. An N+1 cluster and many other topologies are permitted under these rules.