Well, sure, I could leave just the z-wave endpoint at home and move the server to the cloud, but that would mean that none of my automations would work if the network happens to be down. And my ISP is pretty damn good to keep me on line, but that’s one thing of my home automation I’m not willing to compromise. Everything has to be local and not dependent on any kind of connectivity to outside.

Sure, the things rely on the infrastructure (networking very much included) I have in place in my house and it’s not perfect by any stretch and my HA server in itself would most likely be ‘safer’ in the cloud, but it still is my home automation and I want to keep it local to avoid connectivity issues, latency and other stuff beyond my control.

And sure, should my server PSU die tomorrow, it would bring the whole system down. As I mentioned, the setup is far from perfect, but it’s built the way I like it and, for me, this is the best approach. You may weigh pros/cons differently, and that’s perfectly fine. I have my reasons and you have yours, both equally valid.

But I’d still rather not mess with hardware, I just need at least one physical server and other stuff around to keep things running the way I like them.

Without a doubt a lot do, but I personally couldn’t care less. I have a server at home, but that’s just a necessary evil. If I could I’d just rent hardware for everything, but there’s technical and obviously financial limitations with that.

And hosting pretty much anything is practically identical regardless of the platform. Sure, there’s exceptions, like my Home Assistant server with z-wave, which needs to be physically nearby my other stuff, but things like fediverse instances and other browser-based stuff are exactly the same to maintain regardless of the underlying platform.

My personal opinions, not facts:

For hdd’s to be used as long term storage, what is usually the rule of thumb? Are there any recommendations on what drives are usually better for this?

Anything with a long history, like HGST or WD (red series preferably). Backblaze among others publish their data on longevity of drives, so look for what they’re offering. On ebay (and others) there’s refurbished drives available which are pretty promising, but I have no personal experience on those.

Considering this is going to store personal documents and photos, is RAID a must in your opinion? And if so, which configuration?

Depends heavily on your backup scheme, amount of data and available bandwidth (among other things). Raid protects you against a single point of failure on storage. Without raid, you need to replace the drive, pull data back from backups and while that’s happening you don’t have access to the things you stored on the failed disk. With raid you can keep using the environment without interruptions while waiting for a day or two for a replacement. If you have fast connection which can download your backups in less than 24 hours it might be worth the money to skip raid, but if it takes a week or two to pull data back, then the additional cost of raid might be worth it. Also, if you change a lot of data during the day, it’s possible that a drive failure happens before backup is finished and in that case some data is potentially lost.

On which level of RAID you should use, it’s a balancing act. Personally I like to run things with RAID5 or 6 even if I have a pretty decent uplink. Also, you need to consider what’s the acceptable downtime for your services. If you can’t access all of your photos in 48 hours it’s not a end of the world, but if your home automation is offline it can at least increase your electric bill for some amount and maybe cause some inconvenience, depending on how your setup is built.

And in case RAID would be required, is ubuntu server good enough for this? or using something such as unraid is a must?

Ubuntu server is well enough. You can do either sofware raid or LVM for traditionald RAID setup or opt for a more modern approach like zfs.

I was thinking of probably trying to sell the 1660 super while it has some market value. However, I was never able to have the server completely headless. Is there a way to make this happen with a msi tomahawk b450? Or is only possible with an APU (such as 5600g)?

No idea. My server has a on board graphics, but I haven’t used that for years. But it’s a nice option to have in case something goes really wrong. You can still sell your 1660 and replace that with the cheapest GPU you can find from ebay/whatever, at least as long as you’re comfortable with the console you can fix things with anything that can output plain text. If your motherboard has separate remote management (generally not available in consumer grade stuff) it might be enough to skip any kind of GPU, but personally I would not have that kind of setup, even if remote management/console was available.

If you guys find any glaring issues with my setup

I don’t know about actual issues, but I have spinning hard drives a lot older than my kids which still run just fine. Spinning rust is pretty robust (at least in sub 4TB capacity), so unless you really need the speed traditional hard drives still have their place. Sure, a ton more of spinning drives has failed on me than SSD’s, but I have working hard drives older than SSD as a technology has been around (at least in the sense of what we have now), so claiming that SSD’s are more robust (at least on my experience) is just a misnderstood statistics.