VMware Cloud Foundation 9.0 requires strict vSAN ESA hardware compatibility when creating a workload domain that uses vSAN Express Storage Architecture (ESA). During host validation, SDDC Manager and vSphere Client check whether each ESXi host meets ESA requirements, including CPU generation, storage controller type, and—most importantly—ESA-certified NVMe storage devices. The validation errors provided:

“Failed to validate vSAN HCL status” for every host

indicate that the hosts do not meet the vSAN ESA HCL requirements.

VCF 9.0 documentation states that ESA uses a next-generation log-structured filesystem requiring certified NVMe devices only, with no RAID controller dependencies. Unlike OSA, ESA eliminates disk groups, but it requires certified devices listed on the vSAN ESA HCL to pass host validation. If non-certified or unsupported NVMe/SAS devices are present, validation fails exactly as described.

Option A is incorrect because RAID pass-through settings apply to OSA, not ESA.

Option C is incorrect because ESA compatibility validation is performed offline using the SDDC Manager BOM, not via internet lookup.

Option D is incorrect because ESA does not use tri-mode RAID controllers.

Therefore, the documented and verified cause is B: hosts are not using vSAN ESA certified storage devices.