Minimum Requirements

Per Node:

2+ CPU cores (4+ recommended for production)
8GB RAM minimum (16GB+ recommended)
50GB disk for OS (SSD strongly recommended)
Network: 1Gbps minimum (10Gbps for dedicated storage traffic)

Cluster:

3 nodes minimum (for quorum and HA)
Low-latency network between nodes (same LAN ideal)
Shared storage backend (NFS, iSCSI, or local if not using HA)