Last summer my family successfully set up an Unraid server at a remote cabin in the rockies. It's done a great job over the last year helping to monitor the place via cameras and various other sensors. Its biggest problem is that the power is pretty unstable at this cabin. Short 5-20m outages are quite common. So far, the machine has survived a years worth of these unclean shutdowns and the BIOS has been in charge of turning the machine back on when the power is restored. This summer i am hoping to add an UPS as i think that'll allow the machine to glide through most of these outages without incident. But, i do have a question:

If you have Unraid initiate a clean shut down of the machine when the UPS is running low (say 25%), how do you stop the BIOS from just immediately rebooting the machine and repeating that loop until the battery is completely drained and you experience another dirty shutdown?

Will that not happen for some reason? I need the machine to try to turn on as there is no one within a thousand miles of it for 51 weeks of the year. Do i need to set an interval so the machine waits at least an hour between power on attempts? Or is there some level of intelligence that tells the machine dont restart until main power is restored and the battery starts charging?

Regardless of how the system is turned off, when mains power is restored the bios should still turn on the system like it currently does when it detects power.

I personally prefer using the NUT plugin to manage the UPS and system.

1. Mains power is lost, UPS switches to battery.

2. Unraid runs 10 minutes on battery before a shutdown is initiated by UPS signal.

3. Upon system shutdown the UPS is also powered off after Unraid is powered off.

4. Mains power is restored and system boots up, UPS comes online.

Ideally this is how it should function. You will need to research the UPS supports this.

Alright, so as expected Unraid and the UPS are doing battle. I got Unraid to poer down and shut off the UPS. But, the Cyberpower UPS then waits 60s and turns everything back on while still on battery power. How do i stop it from powering on until main power is restored? I only have access to the hardware for another 24h before i have to either return it and try again next year or get it working.

Edited Sunday at 08:00 PM2 days by Jlarimore

Make sure the UPS is told to shutdown on after unraid shuts down, then test a power loss event, when the UPS shuts down, give it a few minutes to see if it powers the system on, it's odd that this would happen.

After that restore power to the UPS and unraid (and the UPS) hopefully come back online together.

Edited Sunday at 08:12 PM2 days by MowMdown

What I suspect is happening is the BIOS is detecting the battery power from the UPS while the UPS is still online (as it's not "off") and triggers a power on event.

If chatgpt is to be believed its a bug with Cyberpower UPSs interacting with the NUT driver in Unraid. If ondelay is > 0 the UPS will turn back on regardless of whether main power has been restored. If ondelay =< 0 the UPS does shut off properly but you cannot delay power on after main power is restored. I need that delay as i expect power to flicker as it returns. Anyone have another good brand of UPS i can try next year?

APC, Eaton, Tripplite all reputable UPS brands

Have you attempted with the built in apcupsd instead of NUT?

15 minutes ago, MowMdown said:

Have you attempted with the built in apcupsd instead of NUT?

Yeah, that failed to shut off the UPS at all. It just remained on despite the tuning being set to shut off. Thats when i switched to NUT.

Made a little headway: It seems there is some kind of hard-coded tuning variable where if the battery is greater than n%, the UPS decides its willing to turn itself back on regardless of main power state. I had the power down tuning at 90% for ease of testing. I decided to try a more realistic 25% number and waited an hour for the battery to drain. (with an ondelay = 90) This time the UPS shut off properly. But, when main power was restored nothing happened after 90 seconds. I'm now not sure if its ever going to come back up. Is 90 actually 90 minutes instead of seconds? Am i waiting for the battery to recharge back to n?

I was doing some reading, and I am invested due to me also owning two cyberpower UPSes

from what I was reading it seems that maybe it's in minutes not seconds? what if you set ondelay=5 for 5 minutes? Im not sure if it converts seconds to minutes or if it just assumed minutes based on the raw number

Edited Sunday at 11:55 PM2 days by MowMdown