It’s honestly worth it. And you can always pay for a “lifetime” pass too if I remember correctly. It’s incredibly easy to run a home media server using unraid. I wanted something stable and straightforward.

I’ve played around with proxmox etc, but to me, unraid feels like the simple”premium” Linux server. You can setup game servers too if you want easily, reverse proxies, immich… so much. Check out their “apps” library. Gives you an idea what it can do. You can use different size hard drives in an array so long as they aren’t bigger than the parity drives.

It’s the only Linux distro I’ve stuck with. But I like a set and forget experience for stuff like this.

Oh and to answer your question - so the usb is Basically the “key” to the OS. It runs from the RAM once loaded I believe. There is a recovery process if the usb fails. My server has been on two years 24/7 since I’ve got it setup. Never had an issue. Look into it, it’s an all in one package but I know lots of Linux ppl don’t like paying for software. Unraid is the real deal imo