NUT Server - Raspberry Pi

NUT UPS setup

Table of contents

  1. Sources
  2. Configuration files summary table
  3. Raspberry Pi Server Configuration Files
    1. ups.conf
    2. upsd.conf
    3. upsd.users
  4. Monitoring Configuration Files
    1. upsmon.conf
    2. nut.conf
  5. Web Interface Configuration Files
    1. hosts.conf
    2. upsset.conf

Sources

There are many online walkthroughs on how to install NUT Server on a Raspberry Pi. Here is the best:

  1. I used the NUTandRpi script to install NUT Server to my Raspberry Pi.
    1. You can also install NUT server manually for any OS.

  2. I used Techno Tim’s NUTandRpi script instructions along with the instructions on the script GitHub page.

    Techno Tim’s walkthrough video:

Configuration files summary table

After installing and experimenting, I became confused on what files are where and what they do. I have documented my setup below to help.

File Purpose File Directory On Server? On Client?
ups.conf Defines UPS hardware and driver /etc/nut/ups.conf ✅ ❌
upsd.conf Configures upsd network listener /etc/nut/upsd.conf ✅ ❌
upsd.users Defines user accounts and permissions for upsd /etc/nut/upsd.users ✅ ❌
upsmon.conf Configures UPS monitoring and shutdown logic /etc/nut/upsmon.conf ✅ ✅
nut.conf Declares system role (standalone, netserver, netclient) /etc/nut/nut.conf ✅ ✅
hosts.conf Lists UPS devices for web UI tools (upsstats.cgi, etc.) /etc/nut/hosts.conf ✅ ❌ (unless running web UI)
upsset.conf Defines host access for the upsset.cgi config tool /etc/nut/upsset.conf ✅ ❌
upssched.conf Configures timed/custom actions during UPS events /etc/nut/upssched.conf ✅ ✅
upssched-cmd User-defined script triggered by upssched (user-defined, e.g. /usr/local/bin/upssched-cmd) ✅ ✅

Raspberry Pi Server Configuration Files

My NUT server configuration is simple because I want my Raspberry Pi to run until it dies if it loses power. My upsmon.conf only monitors and doesn’t require any triggers to execute for shutdown of the NUT server. Therefore, I don’t need upssched.conf to define triggers and actions or the upssched-cmd script to implement them.

ups.conf

  • Purpose: Defines one or more UPS devices and their drivers.
  • Used by: upsdrvctl
  • Location: /etc/nut/ups.conf
  • My file: 
    [ups]
      driver = "usbhid-ups"
      port = "auto"
      vendorid = "0463"
      productid = "FFFF"
      product = "Ellipse ECO"
      serial = "000000000"
      vendor = "EATON"
      bus = "001"

upsd.conf

  • Purpose: Configures how the NUT daemon (upsd) listens for connections.
  • Used by: upsd
  • Location: /etc/nut/upsd.conf
  • My file: 
    LISTEN 0.0.0.0 3493

upsd.users

  • Purpose: Defines users and their permissions (e.g., for monitoring or shutdown).
  • Used by: upsd
  • Location: /etc/nut/upsd.users

  • My file:

      # This is the NUT SERVER user on the Blackberry Pi host and 
  # the NUT CLIENT user on the Synology NAS
  [monuser]
    password = secret
    admin master

  # This is the CLIENT user on the other systems (Proxmox machines)
  [upsmon]
    password = secret
    upsmon slave

Monitoring Configuration Files

upsmon.conf

  • Purpose: Monitors UPS status and triggers system shutdown.
  • Used by: upsmon
  • Location: /etc/nut/upsmon.conf
  • My file (client): 
    MONITOR ups@localhost 1 admin secret master

nut.conf

  • Purpose: Defines the system role: standalone, netserver, or netclient.
  • Used by: All NUT services
  • Location: /etc/nut/nut.conf
  • My file: 
    MODE=netserver   # on server

Web Interface Configuration Files

hosts.conf

  • Purpose: Lists UPS devices for use in the web interface (e.g., upsstats.cgi, upsset.cgi).
  • Used by: Web CGI tools
  • Location: /etc/nut/hosts.conf
  • Example: 
    MONITOR ups@localhost "Sotelo Computer Cabinet UPS"

upsset.conf

  • Purpose: Defines access permissions for the upsset.cgi tool.
  • Used by: upsset.cgi
  • Location: /etc/nut/upsset.conf
  • Example: 
    I_HAVE_SECURED_MY_CGI_DIRECTORY