Yes, you’re right – I was trying to make a GUI vs CLI comparison first and foremost, but then also a OS comparison (Debian being more common than TrueNAS). Isn’t TrueNAS running on Debian Linux?
Do you mind clarifying what this is about?
Can you also clarify what you mean here? I followed felixthecat’s guide to create all my Datasets on TrueNAS Scale (via the GUI); and I pointed volumes in my docker compose files to sub-directories of these Datasets. Is that okay?
Oh right, I did do that.
I get that. I love to learn, for sure; but I did also embark on this TrueNAS journey because I do actually need a NAS to store important files. Everything else – self-hosting Nextcloud, Jellyfin, etc – are nice-to-haves and secondary. I couldn’t care less if those or the OS broke, but I do actually want to preserve my data. If breaking the OS means losing my data, I also want to try to avoid that; unless I already know what to do to retrieve my data quickly in that situation, which I don’t – so that’s why I need to be careful right now as I gain more knowledge. For example, can I link a new install of TrueNAS Scale to existing files on a hard disk that used to live on a Dataset? Can I just pop my hard disks into a Windows system to retrieve my files?
I’m not averse to learning by breaking things; but definitely prefer to learn from other people’s experiences of breaking things, if that’s an option (and in the process save time and effort 
).
One additional question: How do you keep the post-init and docker compose files (did I miss anything else?) version-controlled (and therefore backed up) and easily “redeployed” in a different system? Everything seems scattered and Portainer is a GUI, which I am beginning to think is a bad idea (just for me). I do want to do this before I perform the system reboot.
I appreciate your reading and responding to my long messages, @Scepterus!