[Nut-upsuser] usbhid-ups flooding system log

[Raymond Burkholder]

I wrote up an article regarding this.

NUT USB APC BeagleBone 
<https://blog.raymond.burkholder.net/index.php?/archives/1360-NUT-USB-APC-BeagleBone.html>

For some reason, USB devices 'disconnect' and reconnect. When the device 
reconnects, a new DeviceID is assigned to the USB device. This breaks 
the usbhid-ups drivers supplied by NUT the packages. That is, usbhid-ups 
no longer sees the APC USB device.

To resolve this, I used Debian's udev system to sense the device id 
change and to restart the NUT USB driver.

    # cat /etc/udev/rules.d/89-usb-ups-change.rules
    SUBSYSTEM=="usb", MODE="0660", ACTION=="add",
    ENV{ID_VENDOR_ID}=="051d", ENV{ID_MODEL_ID}=="0003",
    RUN+="/home/debian/usb_add.sh add '$env{DEVNAME}' '$env{ID_USB_SERIAL}'"
    SUBSYSTEM=="usb", MODE="0660", ACTION=="remove",
    RUN+="/home/debian/usb_remove.sh remove $env{DEVNAME}"

Sense a removal, which stops nut.target

    $ cat usb_remove.sh
    #!/usr/bin/env bash

    logger "USB state change detected: $1 $2"
    echo "$(date) USB state change detected: $1 $2" >>
    /home/debian/usb-log.txt
    #systemctl stop nut.target
    exit 0

Sense an addition, which restarts / starts

    $ cat usb_add.sh
    #!/usr/bin/env bash

    logger "USB state change detected: $1 $2 $3"
    echo "$(date) USB state change detected: $1 $2 $3" >>
    /home/debian/usb-log.txt
    systemctl restart nut.target
    exit 0


The blog entry has more detail about parameters

Raymond
https://blog.raymond.burkholder.net


On 2026-07-22 21:02, Robert Nichols via Nut-upsuser wrote:
> Is there a way to prevent the usbhid-ups driver from flooding the 
> system log when a monitored UPS is disconnected from its UCB port. I 
> see a steady stream of messages:
>
>  usbhid-ups[3480520]: libusb1: Could not open any HID devices: 
> insufficient permissions on everything
>
> that are posted every 2 seconds until I comment out that device from 
> ups.conf and restart the nut service.
> Version is nut-2.8.2-1.el8.x86_64 in Rocky Linux 8.
>
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