I have used all three! I started with Server then went to CoreOS running Kubernetes and settled on NixOS which I have been very happy with for about a year now. I run about 25-30 services all using built in modules.
Regarding security, if you are using well crafted modules on NixOS, there should be good systemd hardening in place. That being said there is no reason you can't just use containers on NixOS.
I also find deploying NixOS far superior to butane/ignition used by CoreOS/Fedora. I use nixos-anywhere and can deploy my entire server in a few minutes without manual intervention.
I have been reading about this since the news broke and still can't fully wrap my head around how it works. What an impressive level of sophistication.
Agreed. I used to use Silverblue and it was very stable but did not solve all the problems that Nix addresses. Once you experience the first reinstall with NixOS you will wonder why we did things any other way. It's amazing to just run one command and have things set up exactly how you like.
You might be interested in setting up network bound encryption via Clevis and Tang.
I use a hidden pi zero in my house acting as a Tang server. It's great being able to reboot any of my encrypted servers without having to manually unlock disks.
Framework. I've run Debian, Fedora and for a while now NixOS, all of which have worked flawlessly.
I did have to replace the heatsink/fan part on mine because the fan bearing started clicking, but I'm sure that was just a first generation product issue (I was one of the first batches). I was glad to be able to do the replacement myself at relatively low cost and the process couldn't have been easier (took about 30 minutes).
My previous machine was a 2013-ish ThinkPad X series and the Framework absolutely blows it out of the water. I'm looking forward to upgrading mine to a Ryzen motherboard sometime in the not so distant future.
Every hour via Restic to a local Mino instance on my NAS. Once a day to backblaze B2. Once a week to an offline HDD in my fire safe.
Keep in mind the more often you backup the less total time each backup should take to run. If your backup software isn't too heavy to run and stores backups incrementally, there is little penalty to frequent backups.
Similar to my scheme:
laptop = "laptop"nas = "nas"router = "router"
Then if there are more than one in each category I use nas-0, nas-1, etc.