Hi @raffe
I am using APCUPSD on IPFire as the master. In APCUPSD you can put an “apccontrol killpower” command into your shutdown scripts so that when the master shutsdown it commands the APS to shutdown.
In the NUT manual I see that you can configure the shutdown process to create a POWERDOWNFLAG file which will subsequently cause the UPS to be shutdown.
With the APCUPSD system with an APC UPS, this works for me. I have tested it out as part of my installation process.
Pulled the plug (very nerve wracking) and waited for the UPS to go below its set battery limits, which I set higher so the test occurred quicker. The slave shutdown, followed a bit later by the IPFire master and then shortly after the UPS turned off.
When the power came back then the UPS restarted and that caused the PC’s to restart.
Unfortunately, if your bios does not allow your system to “turn on when power resumes” you may be stuck with your current approach.