HAHA — Home Assistant High Availability. The acronym was unintentional but too fitting to change. Three Proxmox nodes running Home Assistant, Mosquitto, Zigbee2MQTT, ESPHome, and Node-RED in a Pacemaker cluster, because a smart home that dies when one machine fails isn’t really smart.
Overview
| Aspect | Details |
|---|---|
| Nodes | 3 Proxmox hosts |
| Clustering | Pacemaker + Corosync |
| Storage | 3.6TB DRBD dual-primary + OCFS2 |
| Network | 2x10Gbps LACP per node |
| Services | Home Assistant, Mosquitto, Zigbee2MQTT, ESPHome, Node-RED |
Technology Stack
Clustering
- Pacemaker + Corosync with STONITH fencing (3-node cluster)
- Floating virtual IP for seamless failover
- Quorum-based decision making
Storage
- 3.6TB DRBD dual-primary replication
- OCFS2 cluster filesystem shared via NFS
- KINGSTON SFYRD4000G NVMe drives with PCI passthrough
Networking
- LACP etherchannel (2x10Gbps per node)
- Cisco WS-C3850-12X48U switch
- Network-attached IoT peripherals (no USB dependencies)
Dockerized Services
- Home Assistant (core automation)
- Mosquitto (MQTT broker)
- Zigbee2MQTT (Zigbee gateway)
- ESPHome (ESP device management)
- Node-RED (flow-based automation)
IoT Peripherals
- Ethernet Zigbee: TubesZB CC2652P7
- Ethernet Bluetooth: Olimex ESP32-POE-ISO
- USB-free design for clean failover
AI Integration
- Local LLM (Ollama) on RTX 3090 Ti
- Private voice control and inference
- No cloud dependency
Architecture
┌─────────────────────────────────────────────────────────────────┐
│ Floating VIP (Active) │
└───────────────────────────┬─────────────────────────────────────┘
│
┌───────────────────────┼───────────────────────┐
│ │ │
▼ ▼ ▼
┌─────────┐ ┌─────────┐ ┌─────────┐
│ pve01 │ │ pve02 │ │ pve03 │
│ Active │◄─────────►│ Standby │◄─────────►│Arbitrator│
│ │ DRBD │ │ DRBD │ │
└────┬────┘ Sync └────┬────┘ Sync └────┬────┘
│ │ │
│ Corosync Ring │ │
└─────────────────────┴─────────────────────┘
┌─────────────────────────────────────────────────────────────────┐
│ DRBD + OCFS2 + NFS │
│ (3.6TB Replicated Storage) │
└─────────────────────────────────────────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────────────┐
│ Docker Services │
│ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │
│ │Home Assistant│ │ Mosquitto │ │ Zigbee2MQTT │ │
│ └──────────────┘ └──────────────┘ └──────────────┘ │
│ ┌──────────────┐ ┌──────────────┐ │
│ │ ESPHome │ │ Node-RED │ │
│ └──────────────┘ └──────────────┘ │
└─────────────────────────────────────────────────────────────────┘
│
┌──────────────────┼──────────────────┐
▼ ▼ ▼
┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
│ Ethernet Zigbee │ │Ethernet Bluetooth│ │ Local LLM │
│ TubesZB CC2652P7│ │ Olimex ESP32-POE │ │ RTX 3090 Ti │
└─────────────────┘ └─────────────────┘ └─────────────────┘
What I Got Right (and Wrong)
The USB-to-Ethernet migration was the best decision in this project. Zigbee coordinator → TubesZB CC2652P7 (Ethernet), Bluetooth → Olimex ESP32-POE-ISO (Ethernet). USB devices can’t fail over between physical hosts; network devices don’t care which host they’re talking to. Re-pairing dozens of Zigbee devices was painful, but the result is a setup where the smart home stack moves between nodes without caring about peripheral hardware.
Pacemaker tuning took longer than expected. Quorum settings, failure detection timeouts, resource ordering — the defaults are never right for a specific workload, and the documentation explains what the options do but rarely why you’d choose one value over another. DRBD dual-primary with OCFS2 had its own lock contention issues under I/O load that took time to stabilize.
Performance Benchmarks
For IoT workloads, targets are: 50k IOPS, 200 MiB/s bandwidth, 5000 µs latency.
HAHA delivers:
- Random Read: 58.2k IOPS, 227 MiB/s, 4392.34 µs
- Sequential Write: 6.8k IOPS, 852 MiB/s, 9317.05 µs
Meeting or exceeding all targets despite OCFS2/DRBD/NFS network overhead.
Is It Working?
I’ve deliberately failed nodes, pulled network cables, and forced unclean shutdowns. The lights respond, the automations run, the voice assistant answers. Whether a three-node Pacemaker cluster for a smart home is proportionate is a question I prefer not to examine too closely.
Read the full build story in the blog post .