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.