The correct steps are to create an NFS export on the storage array and mount the NFS datastore on each ESX host in the cluster. NFS datastore creation begins on the storage system, where the storage administrator creates and exports the NFS volume or directory with the required access permissions for the ESX hosts. After the export exists, vSphere mounts that export as a datastore. For a clustered VCF workload domain, the datastore must be mounted consistently across all ESX hosts in the cluster so that HA, DRS, vMotion, and VM placement can operate correctly. Mounting the datastore on only one host would create inconsistent datastore accessibility and could prevent workloads from moving or restarting on other hosts. "Attach NFS as a secondary datastore" is not the correct procedural step; the datastore is created and mounted as a vSphere datastore. Configuring vSAN is irrelevant because the workload domain already uses NFS storage and the task is to add another NFS datastore. Reference topics: NFS Datastore Creation, NFS Export, Host Accessibility, VCF Workload Domain Storage Administration.

vSAN ESA Storage Clusters are the optimal choice because the workload profile is capacity-heavy and benefits from disaggregated storage. The requirement for 2.5 PB of application data, archival workloads, gateways, and development/test applications indicates a need to scale storage capacity independently from compute resources. VMware Cloud Foundation describes a vSAN storage cluster as a disaggregated storage solution based on vSAN ESA. It provides storage resources but not compute resources, and its datastore can be mounted by vSAN compute clusters or vSAN HCI clusters. This model is designed for storage-dense environments where capacity and performance can be expanded without adding unnecessary compute. A standard vSAN ESA HCI cluster is excellent for high- performance workloads, but it scales compute and storage together. vSAN OSA all-flash and hybrid use the older disk-group architecture and are less suitable for this large-capacity, storage-centric design. Therefore, the principal storage recommendation should be vSAN ESA Storage Clusters to meet scalability, performance, and capacity growth requirements. Reference topics: vSAN Storage Cluster, Disaggregated Storage, vSAN ESA, Storage Models.

In vSAN ESA, each host uses a storage pool instead of the older OSA disk-group model. The question asks what percentage of that host's local capacity is impacted by the failure of one storage device. Each host has 12 equal-capacity storage devices, and all 12 devices participate in one storage pool. Therefore, one failed device represents one-twelfth of that host's local pool capacity. One divided by twelve equals approximately 8.3%. RAID-6 with FTT=2 determines object resilience across hosts and fault domains, but it does not change the simple local-capacity fraction represented by a single failed disk on one host.
With sufficient cluster resources and policy compliance, vSAN ESA can continue serving data and begin repair or reprotection using remaining capacity. However, the impacted local host capacity is still the failed device's share of the host storage pool. The correct percentage is therefore 8.3%, not 25%,
50%, or 0%. Reference topics: vSAN ESA Storage Pools, Storage Device Failure, RAID-6 FTT=2, Capacity Impact Calculation.