The error message "Failed to validate vSAN HCL status" is a direct indication that the hardware components in the ESXi hosts do not meet the strict certification requirements for the specified vSAN version and architecture. vSAN Express Storage Architecture (ESA) requires that all NVMe storage devices are not only on the general VMware Compatibility Guide (VCG) but are also specifically certified as "vSAN ESA Ready". The host commissioning process within VMware Cloud Foundation (VCF) automates this validation check. The failure means the storage devices installed in the hosts are not on this specific HCL for ESA, thus preventing the creation of the workload domain.

A. While RAID-0/Passthrough mode is a prerequisite for vSAN, the error explicitly cites an "HCL status" failure, which points to hardware incompatibility, not a controller mode configuration.

C. The HCL validation check can use a locally stored database file (vsan-hcl-db.json) and does not strictly require internet access. The error indicates the check was performed but failed on its merits.

D. "Tri-mode" is a feature of some storage controllers, not a required operational mode for vSAN. The critical requirement is passthrough (HBA) mode for direct disk access.

1. VMware vSAN 8.0 Administration Guide, Chapter 2: "vSAN Concepts", Section: "Hardware Requirements for vSAN Express Storage Architecture". This section explicitly states, "All hardware components (storage devices, storage controllers, and server hosts) must be listed in the vSAN section of the VMware Compatibility Guide... For the vSAN ESA, NVMe devices must be identified as supported for the vSAN ESA in the vSAN VCG."

2. VMware Cloud Foundation 5.1 Documentation, Section: "Preparing the ESXi Hosts for VCF". The documentation emphasizes that before commissioning hosts, the administrator must verify that all hardware components, including I/O controllers and storage devices, are compliant with the VMware Compatibility Guide (VCG) for the versions of ESXi and vSAN being deployed.

3. VMware Knowledge Base Article 89433, "vSAN HCL health check fails for vSAN ESA enabled cluster". This article directly addresses the HCL validation failure for ESA. It states the cause is that "The device(s) used are not certified as 'vSAN ESA Ready' on the VMware Compatibility Guide." It instructs the user to verify device compatibility using the official VCG.