Uninterruptible Power

Cyberpower OR2000PFCRT2U
CyberPower Uninterruptable Power Supply (UPS)

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 FunctionUPS DeviceLoad CapacityLocationNotes
Main Server and NAS Drives2 x CyberPower OR2200PFCRTU2 x 2000VA/1540WServer RackLoad shared power backup for Dell Server, NAS devices, and Ethernet Switch
Core Network EquipmentCyberPower PR3000LCDSL3000VA/2700WNetwork RackCovers Router/Firewall, Core Switches, and PoE Wired Devices
Office NAS and ComputersCyberPower OR2200PFCRTU2000VA/1540WOfficeCovers main file storage NAS, Office Ethernet Switch, and Computers

We have standardized CyberPower equipment for this tier.

Cyberpower OR2000PFCRT2U
Generac 20 KW Propane Power Generator

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

Raspberry Pi 4B NUT Server
Raspberry Pi 4B NUT Server

Each of our NUT Raspberry Pi devices is PoE-powered. They are built using the following components:

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 –

Automatic Shutdown

We configured automatic shutdown for our Servers and NAS devices using the following approaches –

The following table shows the overall configuration for out automatic shutdown setup –

DeviceMonitored UPS(s)DelayNotes
NAS-1, NAS-2Network UPS5 minEarly shutdown to conserve battery
NAS-7Network UPS12 minVM/LXC storage - must be longer that servers
NAS-3, NAS-12Server Lower UPS40 minUPS supports longer runtime on battery
NAS-5, NAS-6Server Upper UPS40 minUPS supports longer runtime on battery
NAS-4Office UPS30 minUPS supports longer runtime on battery
PVE1 ServerServer Upper UPS & Server Lower UPS10 minShutdown before
NAS-7
PVE2 & PVE3 ServersNetwork UPS10 minShutdown before
NAS-7

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.

Synology NA UPS Configuration
Synology NA UPS Configuration

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.

Anita's and Fred's Home Lab

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