The vSAN ESA documentation in VCF 9.0 explains that auto-policy management dynamically selects the most efficient data placement policy based on cluster size. For RAID-6 (erasure coding with double parity), the minimum required host count is 6. The docs state:

“RAID-6 (Erasure Coding with FTT=2) requires a minimum of six hosts in a vSAN ESA cluster. This ensures that data and parity components can be distributed across unique failure domains.”

With fewer than six hosts, RAID-6 cannot be enforced and auto-policy management will fall back to RAID-1 mirroring. RAID-6 in vSAN ESA provides higher storage efficiency but comes with stricter host count requirements. Options 2 and 4 are far below requirements, while 8 provides more redundancy but is not the minimum. Therefore, the correct minimum number of hosts for RAID-6 with ESA is 6.