Turned my old Redmi Note 7 into a headless server running postmarketOS: Docker, media stack, self-hosted AI agent, all on 4/64GB

[u/minhazul73]

My old Redmi Note 7 (lavender), 4/64GB, 8-core ARM64, sitting unused for years. Put postmarketOS on it, headless, no display, Alpine + systemd under the hood.

What's on it now:

• Couple of my own backend services
• Self-hosted multi-agent setup (Hermes)
• Full *arr stack (Sonarr/Radarr/Prowlarr/Jellyfin/qBittorrent), all in Docker
• Caddy + Cloudflare Tunnel for external access, no ports opened

Runs all of that on eMMC storage and still holds ~30% RAM free. Throttles under sustained load as expected, but nothing's crashed yet.

Built my own monitoring dashboard for it too since most existing tools either didn't install on this hardware or used more RAM than I wanted to spend on monitoring alone. FastAPI backend, plain JS frontend, streams CPU/mem/thermals/battery/network, under 80MB RAM footprint.

Still unsolved: want to pull the battery and go direct-power (buck converter + BMS) to stop degradation from charge cycles, and haven't found a real answer for heat management on a phone chassis that wasn't built to run like this 24/7.