TL;DR:

• I can't decide between Debian and the new "immutable" Fedora server variants
• Currently I use Debian with pretty much everything being containerised, and it works fine.
• I'm neither very good at what I'm doing, nor want to spend my weekends troubleshooting. Opting for something new could cause some headaches I guess?
• How did you set up CoreOS? Are there simple ways?
• Would you recommend me something different?

My backstory with Debian

I will soon set up a new home server and need your opinion and experiences.

I'm using Debian as the OS for my current one.
While it doesn't match my "taste" perfectly, as I slightly prefer RedHat stuff, I really don't have much preference, since I don't interact with the host much anyway.
Everything is containerised via Docker, and I don't even know why I like Rocky-/ Alma more. I tried Alma once and it just clicked better, I can't explain it...
But that doesn't mean I dislike Debian, not at all!

Still, at that time I decided to go with Debian, since it's the standard for most selfhosters, has the best software support, and is completely community run, opposed to RHEL and its clones.

At that time I didn't know Distrobox/ Toolbx, and I really wanted to install CasaOS (basically a simplified Cockpit + Portainer for less techy people), because I was a total noob back than and didn't want to do everything via CLI.

Nowadays, I found alternatives, like Cockpit, and I also do more via the terminal.
And if I want to install something that doesn't support my host OS, then I just enter my Toolbx and install it there.

Still, I absolutely don't regret going for Debian. It was a good choice. It's solid and doesn't get in my way.

What has changed in the last year(s)

In the last year now, I really began to enjoy using image based distros, especially Fedora Atomic.
I really love Atomic as desktop distro, because it is pretty close to upstream, while still being stable (as in how often things change).

For a desktop workstation, that's great, because DEs for example get only better with each update imo, and I want to be as close to upstream as possible, without sacrificing reliability, like on a rolling release.
The two major releases each year cycle is great for that.

But for a server, even with the more stable kernel that's used in CoreOS from what I've heard, I think that's maybe too unstable?

I think Debian is less maintenance, because it doesn't change as often, and also doesn't require rebooting after each transaction.

But, on the contrary, I wouldn't loose much to the "immutability", because I use containers for everything anyway.
Having way better security (sane SELinux setup, rootless containers, untampered OSA, etc.) and the ability to roll back in case something doesn't work, while self updating, sounds very promising.

Setting up CoreOS; FCOS vs FIOT

The major thing that's keeping me away from CoreOS/ uCore is all the ignition-butane-stuff.
From what I've heard, it's needlessly complicated for home use, and FCOS is best suited for fleets/ clusters of servers, not just for one.

Fedora IOT seems to be simpler, but doesn't have the same great defaults and features as uCore, since there isn't an IOT variant of uBlue.
But hey, at least I have my Anaconda installer.

What do you think about installing IOT, and then rebasing to uCore?
Or, do you think FCOS is just not the right thing for my use case?

In general, do you think that it is worth it, compared to plain old Debian?

Pros vs. cons

Anyway. I'm really thinking about all of this for a long time now, and can't decide.

On the one side, it all sounds promising and great.
But, on the other side, selfhosting isn't a primary hobby of mine. I just want a solid setup I don't have to maintain much after setting everything up. Image based server OSs are still very new and often unheard of, and being an early adopter might cause a lot of headache in that case when it comes to servers.

The "right" use case?

Just in case no one has tried FCOS or FIOT here, I will continue using Debian for my main server, and only use Fedora IOT for my Octoprint server, which only gets turned on sporadically, and would greatly benefit from that.

But if there are positive experiences, then I might give it a try.

Alternatives

Or, would you recommend me something entirely different?

NixOS for example sounds great in theory, but is way too complicated for me personally.

Or, would you recommend me to give Alma another try?

Is there something even better?

First of all, thank you so much for your great answers under my post from yesterday! They were really really helpful!

I've now decided that I will not use something with USB. It really doesn't seem to be reliable enough for constant read-write-tasks, and I don't wanna risk any avoidable data loss and headache.

Also, it just doesn't seem to be very future proof. It would be pretty expensive, only for it to get replaced soon, and then getting obsolete. It just seemed like a band-aid solution tbh. So, no USB hard drive bay, no huge external hard drive, and no NAS just for that purpose.

A few people asked me about the hardware.

My server is a mini-PC/ thin client I bought used for 50 bucks. I've used it for about two years now, and it had even more years of usage under the belt with its' former owner. Imo, that's a very sustainable solution, that worked pretty well until now.

I used it almost exclusively for Nextcloud (AIO), with all the data being stored in the internal 1 TB SSD.

For those who are interested, here are all the hardware details:

<hwinfo -short>

Thing is, I want to get more into selfhosting. For that, my main goal is to
a) Replace Nextcloud with individual (better) services, like Immich and Paperless-ngx.
NC-AIO was extremely simple to set up and worked pretty fine, but I always found it to be bloated and a bit wonky, and, mainly, the AIO takes up all my network and resources. I just want something better, you understand that for sure :)
b) Get more storage. I'm into photography, and all those RAW photos take up SO MUCH SPACE! The internal 1 TB is just not future proof for me.
c) Maybe rework my setup, both in software, and maybe in hardware. Originally, I didn't plan to screw everything, but I think it might be better that way. The setup isn't bad at all, but now, as I got more experience, I just want it to be more solid. But I'm not sure about doing that tbh, since it really isn't a lost case.

As someone already mentioned in the last post, I really don't have a million bucks to create my own data center. I'm not completely broke, but almost :D
Therefore, I just want to make the best out of my already existing hardware if possible.

Because I decided against USB, and because I don't know if there are any slots on the mainboard that can be repurposed for additonal storage, I need your advice if there are any options to achieve that, e.g. via a PCIe slot + adapter, if I had any.
I saw one SATA III port, but that one really isn't enough, especially for extendability.

Here are the photos from both the front and back side:

My thought was, instead of buying one hella expensive 3+TB SSD drive, just screw it and make something better from scratch.

So, if you guys don't give me a silver bullet solution, aka. "you can use this slot and plug in 4 more drives", I will probably have to build my own "perfect" device, with a great case, silent fans, many storage slots, and more.

Btw, do you have any recommendations for that? (What mainboard, which case, etc.) Preferably stuff that I can buy already used.

Thank you so much!

I'm planning to upgrade my home server and need some advice on storage options. I already researched quite a bit and heard so many conflicting opinions and tips.

Sadly, even after asking all those questions to GPT and browsing countless forums, I'm really not sure what I should go with, and need some personal recommendations, experience and tips.

What I want:

• More storage: Right now, I only have 1 TB, which is just the internal SSD of my thin client. This amount of storage will not be sufficient for personal data anymore in the near future, and it already isn't for my movies.
• Splitting the data: I want to use the internal drive just for stuff that actively runs, like the host OS, configs and Docker container data. Those are in one single directory and will be backed up manually from time to time. It wouldn't matter that much if they get lost, since I didn't customize a lot and mostly used defaults for everything. The personal data (documents, photos, logs), backups and movies should each get their own partition (or subvolume).
• Encryption at rest: The personal data are right now unencrypted, and I feel very unwell with that. They definitely have to get encrypted at rest, so that somebody with physical access can't just plug it in and see all my sensitive data in plain text. Backups are already encrypted as is. And for the rest, like movies, astrophotography projects (huge files!), and the host, I absolutely don't care.
• Extendability: If I notice one day that my storage gets insufficient, I want to just plug in another drive and extend my current space.
• Redundancy: At least for the most important data, a hard drive failure shouldn't be a mess. I back them up regularly on an external drive (with Borg) and sometimes manually by just copying the files plainly. Right now, the problem is, if the single drive fails, which it might do, it would be very annoying. I wouldn't loose many data, since they all get synced to my devices and I then can just copy them, and I have two offline backups available just in case, but it would still cause quite some headache.

So, here are my questions:

Best option for adding storage

My Mini-PC sadly has no additional ports for more SATA drives. The only option I see is using the 4 USB 3.0 ports on the backside. And there are a few possibilities how I can do that.

• Option 1: just using "classic" external drives. With that, I could add up to 4 drives. One major drawback of that is the price. Disks with more than 1 TB are very expensive, so I would hit my limit with 4 TB if I don't want to spend a fortune. Also, I'm not sure about the energy supply and stability of the connection. If one drive fails, a big portion of my data is lost too. I can also transform them into a RAID setup, which would half my already limited storage space even more, and then the space wouldn't be enough or extendable anymore. And of course, it would just look very janky too...
• Option 2: The same as above, but with USB hubs. That way, I theoretically could add up to 20 drives, when I have a hub with 5 slots. That would of course be a very suboptimal thing, because I highly doubt that the single USB port can handle the power demand and information speed/ integrity with that huge amount of drives. In reality, I of course wouldn't add that many. Maybe only two per hub, and then set them up as RAID. That would make 4x2 drives.
• And, option 3: Buy a specialized hard drive bay, like this simpler one with two slots or this more expensive one for 4 drives and active cooling. With those, I can just plug in up to 4 drives per bay, and then connect those via USB. The drives get their power not from the USB port, but from their own power supply. Also, they get cooled (either passively via the case if I choose one that fits only two drives, or actively with a cooling fan) and there are options to enable different storage modes, for example a built in RAID. That would make the setup quite a bit simpler, but I'm not sure if I would loose control of formatting the drives how I want them to be if they get managed by the bay.

What would you recommend?

File system

File system type

I will probably choose BTRFS if that is possible. I thought about ZFS too, but since it isn't included by default, and BTRFS does everything I want, I will probably go with BTRFS. It would give me the option for subvolumes, some of which are encrypted, compression, deduplication, RAID or merged drives, and seems to be future proof without any disadvantages. My host OS (Debian) is installed with Ext4, because it came like that by default, and is fine for me. But for storage, something else than Ext4 seems to be the superior choice.

Encryption

Encrypting drives with LUKS is relatively straight forward. Are there simple ways to do that, other than via CLI? Do Cockpit, CasaOS or other web interface tools support that? Something similar to Gnomes' Disk Utility for example, where setting that up is just a few clicks.

How can I unlock the drives automatically when certain conditions are met, e.g. when the server is connected to the home network, or by adding a TPM chip onto the mainboard? Unlocking the volume every time the server reboots would be very annoying.

That of course would compromize the security aspect quite a bit, but it doesn't have to be super secure. Just secure enough, that if a malicious actor (e.g. angry Ex-GF, police raid, someone breaking in, etc.) can't see all my photos by just plugging the drive in. For my threat model, everything that takes more than 15 minutes of guessing unlock options is more than enough. I could even choose "Password123" as password, and that would be fine.

I just want the files to be accessible after unlocking, so the "Encrypt after upload"-option that Nextcloud has or Cryptomator for example isn't an option.

RAID?

From what I've read, RAID is a quite controversial topic. Some people say it's not necessary, and some say that one should never live without. I know that it is NOT a backup solution and does not replace proper 3-2-1-backups.

Thing is, I can't assess how often drives fail, and I would loose half of my available storage, which is limited, especially by $$$. For now, I would only add 1 or max 2 TB, and then upgrade later when I really need it. And for that, having to pay 150€ or 400€ is a huge difference.