My step-up from Pi was to ebay HP 800 G1 minis then G2’s. They are really well made, there’s full repair manuals available, and they are just a pleasure to swap bits in and out. I’ve heard good things about, and expect similar build quality from the 1 liter Lenovos.

I agree that RAM is a likely constraint rather than processor for self-hosting workloads. Particularly in my case as I’m on Proxmox and run all my docker containers in separate LXCs. I run 32GB in the G2’s which was a straightforward upgrade (they take laptop like memory). One some of them I’ve upgraded the SSDs, or if not, I’ve added M.2 NVME drives (that the G2’s have a slot for).

Or SyncThing + Filebrowser

Bare metal servers, VPSs, or VM’s you host? If it’s for VM’s you host, then consider Proxmox as hypervisor and use VM templates. I’m sure old school sysops could to the same with QEMU and Virtmanager or something. But basically, I just set up a VM exactly how I like it, then convert it to a template and cookie cutter it out.

I can sense the Nix guys shaking their heads - it’s on my list to try :- )

It has a practical element (Hello Jellyfin, Kavita, AudioBookshelf & Syncthing), but for the rest of it, it’s about 60% hobby and 20% learning stuff that could be potentially career enhancing.

Gnu/Linux absolutely annihilating server operating systems means that I can run the same stack, and use the same tools, that giant companies are based on. All for free. In my spare room. 1L x86 computers cost less than two packs of cigarettes! Little SSD’s are ridiculously cheap. And you don’t even need that stuff - that old laptop in your cupboard will do. Even if you kick in to donate for your software (and I recommend you do if you can) it’s a cheap hobby compared to golf or skating or whatever. Anything you need to learn there’s blog posts and videos available.

We live in an amazing time in this hobby. I know there’s companies that would like to take it away from us, but Open Source just keeps kicking goals. Thank you FOSS developers, Gnu, Linus, FSM, Cthulhu and the other forces in the universe that make this possible.

This is a genuinely fresh and intriguing idea, but you’ve sort of answered your own question (as have most of the commenters) by noting it would immediately be abused. So I think you are going to have to be the one deciding how your compute cycles and bandwidth are being used.

BOINC/World Community Grid is the obvious choice since they are set up for exactly this use case. There’s also things like Sheepit - a render farm. Maybe you could run a Tor node .

I’d had a bit of Linux server experience, but no desktop Linux. I tried Pop!_OS on an old macbook and everything just worked. I could figure out what was going on without any drama.

+1 for Pop. I’ve just done this. I had to run updates plugged into the cat 6 to get wireless, apart from that, everything just worked.