An administrator is tasked with designing a highly available vSAN ESA two-node cluster for a...

The minimum total number of nested fault domains is six. In a two-node vSAN design, site disaster tolerance is provided through host mirroring between the two data hosts, with a witness maintaining quorum. The requirement adds another layer: the solution must also survive a disk group or local storage failure in addition to a host failure. vSAN’s two-node host mirroring rule states that each data host must have at least three disk groups, or three disks in a storage pool, to use the rule. In ESA, the equivalent construct is disks in the storage pool rather than OSA-style disk groups. Because there are two data hosts, and each data host requires three nested placement units, the minimum total is 3 + 3 = 6 nested fault domains. Four would not meet the host-mirroring rule requirement, and two would only represent the two hosts without local storage fault isolation. Reference topics: vSAN Two-Node Cluster, Host Mirroring, Nested Fault Domains, vSAN ESA Storage Pool Placement.