| Area | Single-zone mirroring | Single-zone HPEC 4D+2P | Multi-zone mirroring |
|---|---|---|---|
| Nodes | 3, 6, 9, 12, 15, 18 | 6, 12, 18 | 2 to 18 (data) + 1 tiebreaker |
| Failure tolerance | Up to 1 node/drive | Up to 2 nodes/drives | Plus‑1 across 3 fault domains |
| Capacity efficiency | Approx. 40–48% | Approx. 50–65% (excl. rebuild) | Approx. 40–48% |
| Protocols | iSCSI / NVMe/TCP | iSCSI / NVMe/TCP | iSCSI / NVMe/TCP |
| Placement | Groups of 3 | Groups of 6 | By fault domain (zones) |