2026-09-23

The Raspberry Pi Foundation has published a detailed guide on building a 'digitally sovereign second brain' — essentially a self-hosted knowledge management system running entirely on your own hardware.

The idea is straightforward: instead of trusting Notion, Obsidian Sync, or Google Keep with your notes, bookmarks, and research, you run the whole stack on a Pi at home. You keep your data, you control access, and there's no monthly subscription bleeding away.

Why homelabbers should care

This sits right in the sweet spot of what a homelab is for — practical self-hosting that actually replaces a paid service. If you're already running a Pi for Home Assistant or Pi-hole, adding a knowledge base is a low-effort win. The guide walks through the software choices and setup, so even if you're relatively new to self-hosting, it's approachable.

It's also a genuine use case for that spare Pi 4 or 5 sitting in a drawer. Low power draw, always on, accessible from any device on your network (or via a VPN/tunnel if you want remote access).

Caveats

You'll want to think about backups — a single SD card is not a resilience strategy. An external SSD makes this much more robust and the performance difference is noticeable. You're also your own sysadmin here, so updates and security are on you.

The guide leans fairly beginner-friendly, so experienced self-hosters might find it light on detail. But as a starting point and a nudge to actually do it rather than just bookmark the idea, it's solid.

What to grab

If you're booting from an external drive (you should be), an M.2 NGFF to USB 3.0 Aluminium SSD Enclosure – Portable Homelab Storage paired with a spare M.2 NGFF SSD keeps things compact and fast. For the Pi itself, an Raspberry Pi 5 is the obvious pick if you don't already have one spare. Read the full guide on the Raspberry Pi blog.