I recently replaced my UPS and set up NUT (Network UPS Tools) for monitoring.
Everything works fine for a short time, but after a few hours, NUT reports “error: Data stale” in the web UI. After a few more hours, the web UI just stops responding completely.
I have NUT running on a Ubuntu VM in Proxmox. My UPS is a Tripp Lite (Eaton) SU1000RTXL2UA. It’s connected to my hypervisor via USB and passed through to the VM. Restarting the container fixes the problem. Any idea what could be causing this?
When it gets in the problem state, does the UPS respond when you use upsc to check its status in a terminal in the vm?
If so it might be taking too long to respond when it is being checked by the daemon. If so setting MAXAGE to something higher than the 15s default may help. A lot of people raise it to 25 for this symptom. But this will only help if the driver is still connecting to the UPS ok. If it’s not then it may be a problem with the USB connection or the UPS.