Rebuilding the home lab on a single mini PC

For about four years the shelf in the hallway held three machines: an old tower acting as a file server, a small desktop running a hypervisor, and a single-board computer doing DNS and a few scripts. Together they drew more power than the fridge and sounded like a small aircraft every time a backup started.

This summer I replaced all of it with one fanless mini PC: a low-power x86 chip, 32 GB of RAM and two NVMe drives in a mirror. Here is what moved, what did not, and what I would do differently.

What moved easily

Almost everything that was already a container. A compose file, a data directory, and a quick rsync later, it was running on the new box. The DNS resolver, the media server and the backup target were done in one evening.

What did not

The two virtual machines I had kept "just in case" turned out to hold nothing I still needed. I exported their disks to cold storage and deleted them. The hardest part was the file server: years of shares with odd permissions. I ended up starting fresh with one share per person and copying data by hand.

Numbers

before: ~95 W idle, three boxes, two UPS outlets
after:  ~11 W idle, one box, silent

Lessons

Write down what each service actually does before migrating. Half of mine existed only because I had forgotten to turn them off. And test the restore, not just the backup — I found out my old backup script had been skipping one directory since 2023.