UPS master via USB

  • I am running 2.4.4 of pfSense.

    I have a UPS connected to my pfSense router using a USB cable. I did have some trouble with this and opened ticket #9849 on this. That said, I found a work-around to get my UPS to be identified by pfSense/NUT.

    I have pfSense and another server connected to the UPS. The other server supports NUT. I would like a setup very similar to what is discussed in UPS configuration master/slave, except I am not using an ethernet connection to manage my UPS, rather I am using USB. What I have not seen is how to configure pfSense to act as the "Master" with NUT. Do I need to do anything? Or by virtue of connecting the UPS to pfSense via the USB cable is it implied that it is the master?

    Also, how would I configure pfSense to wait until the UPS is down to 5-10% before shutting down? Will I get email notifications if the power goes out? Can I get a notification if the battery power drops below 50% (in case the batteries start going bad)? Or does NUT also monitor battery health and will notify me?


  • Is this in the right forum?

  • FWIW, I figured this out. I had to navigate to Services > UPS. Then select the UPS Settings tab. From the settings page, click the "Display Advanced" button.

    In upsmon.conf add the following:

    RUN_AS_USER root

    This is a work-around to sending email notifications. See post #642812 in the NUT package thread.

    In ups.conf add the following:

    user = root

    This will cause upsdrvctl to run as root.

    In upsd.conf add the following:


    This will cause the UPS daemon to listen on localhost as well as my LAN IP so that a "slave" can connect to it.

Log in to reply