I feel super dumb right now.
I always thought, that all user data (/home/) are decently safe against physical access, as long as my user and root password is strong enough. If I just plug in the hard drive, nobody except the Super User has access to the data on it.
Well, the guys on the other community (Link) have shown me how wrong I've been.
All of my devices are securely encrypted. Well, all of them, except the most important one: my server, where all pictures, documents and other private stuff is stored.
Now, I'm afraid as hell that this will go wrong in the future.
Imagine a vengeful ex girlfriend, a police raid, whatever.
It's just dumb from my side to secure everything except the one thing that would need it the most.
I've already done my homework, and encryption doesn't seem like a highly important topic in the selfhosting community, or on many servers else.
At least that's what I've got the feeling.
The most common argument I hear is "nobody will get physical access anyway, so I don't care".
Threat model and security measures
My threat model: not high. I don't do any illegal stuff and don't have any enemies. Still, I want everything at least somewhat secure.
If it only serves the purpose to annoy the intruder it's already enough.
The only thing that has online access is my Nextcloud (AIO from Docker), and that is already well secured against hacking attacks (password, 2FA, brute force protection, etc.).
It's also the only thing that is worth securing in my eyes.
Options for encryption
LUKS2 full disk
I would need to factory reset the whole server for that, which would be ... highly inconvenient for me. It took me quite a long time to get everything working, and I don't wanna loose my configuration.
Also, how should I access the device when I don't see anything? Is there a workaround or something when I want to reboot without a monitor and keyboard?
Only encrypt the home folder
Same problem as with FDE
Nextcloud server side encryption
That one isn't recommended from what I've read. It causes compatibility issues and an extreme hit on performance according to forums. Is this still correct?
Cryptomator (?)
Encrypting and decrypting with every up- and download sounds quite annoying. Wouldn't be my prefered method tbh.
What is your opinion on that topic? What would you recommend me?
Please remember, that I'm not that experienced as much, so please be patient with me 😬
This is your actual problem you need to solve. Reinstalling your server should be as convenient as installing a basic OS and running a configuration script. It needs to be reproducible and documented, not some mystery black box of subtle configurations you've forgotten about ages ago. A nice, idempotent configuration script is both convenient and a self-documenting system for tracking all the changes you've ever implemented on your server.
Once you can do that, adding whatever encryption you want is just a matter of finding the right sequence of commands, testing it (in another docker perhaps) and then running your configuration script to migrate your server into the desired state.
I detect a NixOS shill 😛
Seriously though, if OP doesn't want to use another OS, I can recommend using Ansible.
Nah, I wanted to love NixOS, and granted it seems like a perfect fit for my recommendation, but a bunch of things about it rub me the wrong way. It's just not for me. I've always been most comfortable with Debian and that's what my setup script is designed for. Lots of apt.