High-Density 3-Node Proxmox VE 8 Cluster with Ceph & Corosync

1. Topology Overview

A resilient 3-node virtualization cluster provides high availability without split-brain risk. Using 3x AMD Ryzen 7 7840HS mini PCs (64GB DDR5 each) connected via a dedicated 2.5GbE/10G network switch yields 24 physical cores, 48 threads, and 192GB total RAM at under 90W idle.

2. Network Configuration

Isolate Corosync heartbeat latency on a dedicated VLAN with low MTU, and configure Ceph storage traffic on a separate high-throughput link with MTU 9000 (Jumbo Frames).

auto vmbr0
iface vmbr0 inet static
    address 10.0.10.11/24
    gateway 10.0.10.1
    bridge-ports eno1
    bridge-stp off
    bridge-fd 0

auto vmbr1
iface vmbr1 inet static
    address 10.0.20.11/24
    bridge-ports eno2
    mtu 9000 # Dedicated Ceph & Migration Network

3. Ceph Storage Configuration

Assign dedicated 2TB PCIe 4.0 NVMe SSDs per node as OSDs with a pool size of 3 and min_size of 2 for zero-loss synchronous replication.