A container does not make restoring easier in the situation you have described.

The host for the containers still needs to be configured. That's where changes to NIC identifiers, etc. need to be handled.

In my situation, the host gets exactly the same configuration. The only things that care about the name of the NIC are a quick grep -r away in /etc/; 95% of everything will be up when I get the firewall script redone, and because that's properly parameterized, I only need to change the value of $IF_MAIN at the top.

On Windows platforms that's usually true.

I've not met a linux system tarball that I can't drop on any other machine with the same CPU architecture, and get up and running with only minor tweaks network device names.

> Does a backup work then, even if all the hardware is different

Full disk backup, Linux ? Most likely. We rarely recompile kernels these days to tailor to some specific hardware, most are supported via modules. It could be that some adjustments are going to be necessary (network interface names? nonfree drivers). For the most part, it should work.

Windows? YMMV. 10 is much better than it was before and has more functional disk drivers out of the box. Maybe you need to reactivate.

The problem is mostly reproducibility. A system that has lived long enough will be full of tiny tweaks that you don't remember about anymore. Maybe it's fine for personal use but it has a price.

Even personal servers (including Raspberry Pis) I try to keep some basic automation in place so if they give up the ghost, they are cattle. Not pets.

As someone who just switched motherboard + cpu on my home server, the worst thing was to figure out the names of the network interfaces.

EnpXs0 feels worse than good old ethX with interface naming based on mac addresses.

It feels worse, but you'll be even less happy when you add or remove a NIC and all of the existing interfaces get renamed.

But if you really want to, you can rename them to anything you want with udev rules.

But this is happening with enpXsY! (Are you saying this was only happening with eth*?)

Whenever I remove a card from my first pci slot, the other two cards get renamed... Frustrates me a lot.

Why wouldn't it? Unless you are changing architecture after a component of your system dies, there's no reason your old binaries would not work.

Drivers, config you missed/didn't realise was relevant/wasn't needed before, IDs (e.g. disks), etc.

Nix or aconfmgr (for Arch) help.

I still like containers for this though. Scalability doesn't mean I'm fooling myself into thinking hundreds of thousands of people are reading my blog, it means my personal use can outgrow the old old PC 'server' it's on and spill into the new old one, for example. Or that, for simplicity of configuration, each disk will be (the sole disk) mounted by a Pi.

There's more than one way to skin a cat. If you're running something as simple and low profile as OP suggested, all you need to backup from the system are the packages you installed and a handful of configurations you changed in /etc. That could be in ansible, but it could be just a .sh file, really. You'll also need a backup of the actual data, not the entire /. Although, even if all you did was backup the entire / there's a good chance it would work even if you try to recover it in new hardware.

The services metioned by OP don't need to talk to each other, they are all things that work out of the box by just running apt-get install or equivalent. You don't need anything really fancy and you can set up a new box with part of the services if they are ever taking too much resources (which, for a small setup, will likely never really happen. At least in my experience)