UPS disconnects from USB once or twice per day

Installing and Using OpenWrt
1

Hi, I have BPI-R3 router and Powerwalker VI 2200 SHL UPS. UPS is connected to router via USB (directly to USB3 port without any hubs). NUT installed on router with recommended usbhid-ups driver (other drivers like blazer-ups don't work). UPS info shows, that UPS needs only 100 mA current. It works, I can see UPS status etc. But once or twice per day it "hangs". I'm not sure, what exactly hangs, but router just can't receive any info from ups in that case (shows "data stale" in NUT).

I experimented with some parameters in NUT (pollinterval, pollfreq, maxage), but there is no effect. Lsusb command properly shows UPS in all time (during "hangs" it shows ups too).

Router begins to receive UPS data only after router reboot or running this command:

usbreset "Offline UPS"

How can I resolve this issue?

2

I've seen this same thing from time to time. I don't know why it happens. My solution has just been to restart the router and it resolves for quite a while. Have you tried this?

I wish I could give a better answer, but I have not yet figured out exactly what triggers this problem.

FWIW, my setup is a Cyberpower UPS + a dedicated TL-MR3020v1 running 18.06 (in a bit of "don't try this at home, folks... yes 18.06, it is super ancient and unsupported. But wifi is disabled, it runs no other services aside from NUT and ssh, and it lives on a trusted network behind a firewall).

3

Router reboot or usbreset "Offline UPS" command works, but this is temporary solution. It will "hang" again after 10-20 hours.

BTW, router runs on latest snapshot (BPI-R3 don't have stable OpenWRT version yet).

Maybe I will write a script, which will run usbreset command after finding some log entry. But it is not an elegant solution.

4

Consider a cron job that reads the data from the UPS and restarts the driver in case of failure.

5

this is an issue with NUT on all linux distros. You will not have any success unfortunately. You could scour the online forums for persons who have success with exactly your brand and model to find out what those settings are but good luck with that. Believe me I have spent days even weeks on NUT and gave up in the end. Really not worth the effort. For my linux servers I only purchase UPS that have native linux drivers such as APC and CyberPower and avoid NUT completely. Keep in mind your UPS needs to shutdown the operating system, go into hibernation, then restore power to its outlets when power returns. A wrong configuration in NUT could mean your systems not powering off gracefully or restoring power to the servers when power returns. Scenarios which could cause havoc with production servers.

I believe Openwrt has native drivers for APC. Best go buy a new UPS.

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