Ahaa, so what you are saying that me seeing the input load on UPS is not the cause of the measured power consumption but just a “symptom”. That something (be it TrueNAS/rpi/switch) really draws more. How can I do a thorough analysis of what the devices do? Normally I check logs and htop and see they are just chilling. I check cpu, i/o and network and I thought that it should be pretty good indicator of if something is happening. Especially when its 6 Watts more thats like whole another rpi 😀
(Alternative below) Buy 5 - 7 years old computer with decent specs (i5 i7, 16 gigs ram, don’t care about hard drives but prefer ones with ssd) for about 60 - 100 bucks. Buy 250 gigz+ ssd (if it’s not included) and any desired number and sizes of nas grade drives (this is where you don’t want to save money if you want this full fledged nas). Don’t forget UPS! Install TrueNAS. Profit… Ok not profit but enjoy. For movies definitely jellyfin (keep your distance from plex really). Audiobookshelf for audiobooks but also ebooks! Amazing software that one.
Alt. Buy raspberry pi, two usb hard drives, install open media vault and same apps as above. Setup data duplication from one drive to the second one with rsync (directly in omv ui). Omv is not as polished as true nas but its cheap and it lets you dip your feet in homelabbing first, in two to three years you will gain experience and vision to do your dream homelab (or at last try 😀) if the pi is not enough.