tvcvt
I’d second this. I’ve installed Proxmox installed on some Mac Minis and they do a credible job of it. A beefy Max Pro would be all the better.
I’ll add that if the main purpose is to be a NAS something like TrueNAS will be much more set-and-forget.
This is grossly overpowered for a firewall, so I wouldn’t go that route unless you want to do a virtual firewall on top of a general purpose hypervisor.
Since you’re new to this and therefore probably haven’t set up too much infrastructure yet, let me put in a plug for ZFS for the file system underlying your data. That will unlock for you snapshots and the ability to send very efficient backups off site to another ZFS pool.
There are commercial offerings for all this (I think rsync.net will give you a ZFS target), but I essentially have a second NAS set up at another location for the purpose.
Beyond that, I’m also a big fan of BackBlaze B2, which can give you object-based online storage.
As far as what to back up, that’ll depend on your setup. I usually find it simplest to backup my entire VM and do recovery by restoring the VM.
I’ve been meaning for years to set up a solid archiving system that I don’t have to manually babysit. I’ve had my eye on mailpiler (https://www.mailpiler.org/), but haven’t found the time to get up to speed on it. I’m the meantime, I drag messages to a local folder like a barbarian.
If you want an image, it doesn’t matter what the underlying file system is. You should be able to use a tool like Clonezilla and get a 1:1 copy. Depending how you’ve set up partitioning, you could also use sgdisk to set up the proper partitions and zfs send/recv for the new data portion of the drive and install a boot loader. That’s probably the way I’d go in this instance.
The way I’ve ended up going is to just use a standard keyboard and monitor with a KVM over IP switch. In the US it’s not hard to find relatively inexpensive ones on the used market, but they do require a module for each computer, which can increase the costs. I’ve had good luck finding the Avocent MPU2016 switches. Worth a look on eBay anyway.
You’ve got some decent answers already, but since you’re getting interested in ZFS, I wanted to make sure you know about discourse.practicalzfs.com. It’s the successor to the ZFS subreddit and it’s a great place to get expert advice.
This promises to be a fun project!
It sounds to me like you have above-average demands on your network and I’d agree that UniFi (and therefore probably Omada) are not what I’d consider great as routers/firewalls.
I’m a fan of pfSense/OPNSense for that purpose, which you can install on pretty much any x86_64 hardware. They’re both wonderful and you can fine tune to your heart’s content or get them set the way you like and leave them.
If you really like a dedicated router appliance, I do like the Mikrotiks, too, but you’d have to study their sometimes-peculiar way of doing things.
To my tastes, UniFi does great at switching and wireless, but any of you’re unhappy with that direction, I’ve heard good things about Omada and the Aruba stuff is fantastic. I recently have been playing with some used iap-325s from eBay. I picked them up for $25 and they’ve been terrific.
You could likely use dd or clonezilla to create a duplicate of your boot drive and boot your laptop right from that, but that’s not quite what you’re after.
There are some distros lately that use a declarative config file to set the whole thing up that I think is much more what you have in mind. The big ones that come up a lot are nixOS and Fedora Silverblue. Maybe one of those systems would be to your liking.