Uninterruptible power for our network, servers, and storage is key to our Home Lab’s high-availability strategy.
Our Home uses residential power, so we experience frequent power interruptions. Here in New England, storms and wind events cause power outages lasting from a few seconds to as long as a week. As a result, we need a reliable, tiered power backup system to protect our equipment and keep our Home Lab online.
Power Architecture
We use a two-tiered power architecture. The first tier uses sine-wave Uninterruptable Power Supplies (UPSs) to protect our equipment from surges and provide a few minutes to maybe an hour of backup power.
| Backup Function | UPS Device | Load Capacity | Location | Notes |
|---|---|---|---|---|
| Main Server and NAS Drives | 2 x CyberPower OR2200PFCRTU | 2 x 2000VA/1540W | Server Rack | Load shared power backup for Dell Server, NAS devices, and Ethernet Switch |
| Core Network Equipment | CyberPower PR3000LCDSL | 3000VA/2700W | Network Rack | Covers Router/Firewall, Core Switches, and PoE Wired Devices |
| Office NAS and Computers | CyberPower OR2200PFCRTU | 2000VA/1540W | Office | Covers main file storage NAS, Office Ethernet Switch, and Computers |
We have standardized CyberPower equipment for this tier.
The second tier uses a Generac 20 KW whole-house generator. The generator system automatically kicks in about a minute after an extended power failure begins. Our generator and associated large propane tank can power our home, including our Home Lab and Amateur Radio Station, for 7 – 10 days. Our generator system includes automatic load heading devices for our air conditioner, range, hot tub, and other high-current devices to avoid overloading our generator.
Redundant Internet
A weak link in our power backup strategy is our Internet connection. Our modems are backed up by our two-tier power management system. We also have redundant connections to fiber- and cable-based ISPs to provide additional resilience in the face of wide-area power outages.
Power Monitoring and Managed Shutdown
We are using the Network UPS Tools software running on Raspberry Pi computers to manage our critical UPS devices. This software allows us to remotely monitor the operational condition of our UPS devices and enables our Storage Devices and Servers to sense conditions when a complete backup power loss is imminent and perform a controlled shutdown to protect themselves and the data that they store. You can find a summary of the available features here.
NUT Setup and Configuration
Each of our NUT Raspberry Pi devices is PoE-powered. They are built using the following components:
- An 8 GB Raspberry Pi 4B Single-Board Computer
- A Raspberry Pi PoE+ HAT with Low Profile Heatsink
- A SanDisk 32GB Ultra microSDHC UHS-I Memory Card
- A tall aluminum case
We have moved our NUT servers to a rack-mount solution. You can learn more about it here.
Software Components and Installation
We followed the process in the following video to install the software on each of our NUT Servers.
The software components required are as follows –
- Raspberry Pi OS Lite 64-bit
- NUT Software Tools for Debian Linux (installed via apt install; see video for details)
- Synology DSM UPS Server Support Software
Automatic Shutdown
We configured automatic shutdown for our Servers and NAS devices using the following approaches –
- Automatic Shutdown for Proxmox; the video above is also useful for configuring NUT client support in Proxmox
- Automatic Shutdown for Synology NAS devices
The following table shows the overall configuration for out automatic shutdown setup –
| Device | Monitored UPS(s) | Delay | Notes |
|---|---|---|---|
| NAS-1, NAS-2 | NAS Upper UPS & NAS Lower UPS | 20 min | UPS supports longer runtime on battery |
| NAS-3 | Server Lower UPS | 20 min | UPS supports longer runtime on battery |
| NAS-4 | Server Upper UPS & Server Lower UPS | 20 min | UPS supports longer runtime on battery |
| NAS-5 | Server Upper UPS | 20 min | UPS supports longer runtime on battery |
| NAS-6 | Network UPS | 5 min | Early shutdown to conserve battery |
| NAS-7 | Network UPS | 12 min | VM/LXC storage - must be longer that servers |
| PVE1 Server | Server Upper UPS & Server Lower UPS | 10 min | Shutdown before NAS-7 |
| PVE2 & PVE3 Servers | Network UPS | 10 min | Shutdown before NAS-7 |
| NAS-11 (Pi NAS) | NAS Upper UPS | n/a | No NUT support |
| NAS-12 (Pi NAS) | NAS Upper UPS | n/a | No NUT support |
Configuring Synology NASs
Configuring a Synology NAS device to use our NUT servers is straightforward once the NUT servers are properly configured to meet the interface Synology DSM expects.
Configuring Proxmox Servers
Steps to configure a Proxmox server to work with a NUT server is more complex. The basic steps are:
Ensure that email support is working on the server (we used Postfix to enable mail forwarding)
Install the NUT Client Package
apt-get install nut-client
Configure the NUT Client
# Edit the following files in /etc/nut
vi /etc/nut/nut.conf vi /etc/nut/upsmon.conf vi /etc/nut/upssched.conf
Create a custom shell script to process various UPS events. The script includes e-mail notifications and logging as is placed in the /etc/nut directory.
With these steps completed, we can restart the NUT client by rebooting the server.
