--- name: system-architect description: Sam's NixOS multi-machine infrastructure. Use for any task involving system config, cross-machine deployment, Docker, audio (Snapcast), MQTT (Mosquitto), NixOS flakes, Ubuntu, Sys Config, Nvim, Home Assistant. compatibility: NixOS 25.11+, Home Manager, flakes metadata: machines: - name: sam-4screen-desktop ip: 192.168.20.27 type: Desktop os: "NixOS, Niri" role: Main dev machine. Sync to sam-ubuntu1. tech: Mainly terminal dev work with Nvim, Opencode, Pi dev code. hardware: cpu: model: "Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz" cores: 4 threads: 8 ram: total_gb: 62 gpu: - Intel HD Graphics 630 (i915) — drives the 4 display outputs - NVIDIA Quadro P620 2GB (nvidia 580.173.02) disks: - device: /dev/nvme0n1p2 size: 869G mountpoint: / note: "ext4, 66% used (2026-10-05)" - device: /dev/nvme0n1p3 size: 69G mountpoint: "[SWAP]" - device: efivarfs size: 256K mountpoint: /sys/firmware/efi/efivars - device: /dev/nvme0n1p1 size: 1022M mountpoint: /boot - device: /dev/sda2 size: 224G mountpoint: "(not mounted)" note: NTFS verified: 2026-10-05 - name: nixos-desktop type: Desktop ip: 192.168.20.13 os: "NixOS 26.11 (Zokor), KDE Plasma 6 / KWin Wayland (SDDM)" role: Always-on web-facing server. Docker host + native services. Memory-bound — do not treat as CPU-bound. tech: Docker (OmniRoute, Outline, n8n, Pi-hole replica + nebulasync, Mosquitto, voice_bridge/voice_whisper, speech_piper, pocketbase, family-home-lab, dsh, worldmonitor, prefect, litellm, headroom/JEV), Caddy :8000 serving /var/www, snapcast, librespot, mopidy, native PostgreSQL :5433 (paperclip), paperclipai, Paseo Daemon, where-woof hardware: cpu: model: "AMD Ryzen 5 5600 6-Core Processor" cores: 6 threads: 12 ram: total_gb: 15 note: "6.8 GiB used; swap 7.1 GiB of 8.8 GiB used (81%) - 2026-10-05" gpu: - "NVIDIA GTX 760 (Kepler, PCI 10de:11c2) - DEAD. No driver bound; only /dev/dri/card0 simple-framebuffer. /proc/driver/nvidia absent. Desktop renders via software (llvmpipe). hardware.nvidia.open=true can never work on Kepler (open modules need Turing+). Recommended replacement: AMD RX 6600 (in-kernel amdgpu)." disks: - device: /dev/sda2 size: 907G mountpoint: / note: "ext4, 459G used (54%) - 2026-10-05" - device: /dev/sda3 size: 8.8G mountpoint: "[SWAP]" note: "81% full - the main resource problem on this machine" - device: /dev/sda1 size: 1022M mountpoint: /boot - device: /dev/sdb2 size: 916G mountpoint: /mnt/storage note: empty spare - device: /dev/sdc2 size: 1.8T mountpoint: /mnt/data note: "21% used" - device: /dev/sdd1 size: 2.7T mountpoint: /mnt/ubuntu_storage_3TB note: "USB drive - photo master + Borg backup target for .27 and .13. Letter shifts on replug (has been sdd1/sde1)." - device: /dev/sde1 size: 1.4T mountpoint: "(not mounted)" note: MaxtorBackup, old migration tarballs caveats: - "Device letters are NOT stable - NixOS mounts by UUID. Always check lsblk/df before using a device path." - "GPU is dead: no hardware acceleration. KDE session costs ~2.4 GB because of software rendering plus 28-day uptime." - "litellm and headroom are idle and almost entirely swapped out (~1.05 GB of swap combined)." - "Dead stacks to ignore: airflow (7 containers exited, 24 GB of logs in /home/sam/deployment/airflow/logs), engram container (never started - the live engram is a user systemd service on :7437 and its DB is empty), trigger_dev, t3_stack_react, sams-home-network." - "There is a SECOND airflow install at /home/sam/deployment/ai-resume/airflow/ - also not running." verified: 2026-10-05 - name: sam-ubuntu1 type: virtual machine ip: 192.168.20.35 os: Ubuntu role: Ubuntu in Virtual Machine on Proxmox. Docker Machine for home network. tech: Mainly Docker hardware: cpu: model: "Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz" cores: 2 threads: 2 ram: total_gb: 14.2 gpu: disks: - device: /dev/sda2 size: 442G mountpoint: / - device: "//192.168.20.23/usb_3tb" size: 2.7T mountpoint: /mnt/nfs_usb_3tb - name: home-assistant type: virtual machine ip: 192.168.20.30 os: Home Assistant OS role: Runs Home Assistant in a virtual machine on Proxmox Hypervisor tech: Home Assistant OS - name: file-server type: virtual machine ip: 192.168.20.23 os: role: File server on Proxmox Hypervisor tech: File Server - name: proxmox-backup type: virtual machine ip: 192.168.20.48 os: Proxmox Backup Server role: Runs standard proxmox backup server tech: Proxmox - name: proxmox type: hypervisor ip: 192.168.20.28 os: Proxmox VE role: Hypervisor hosting all VMs (sam-ubuntu1 .35, file-server .23, home-assistant .30, proxmox-backup .48) tech: Web UI https://192.168.20.28:8006, SSH root@192.168.20.28 - name: skinnyspeakers type: raspberry pi ip: 192.168.20.24 os: Raspbian 12 (bookworm) role: Speaker/audio client, likely Snapcast speaker. Identified 2026-08-29 (was previously unknown .24) tech: SSH sam@192.168.20.24 - name: sam-thinkpad type: Laptop ip: 192.168.20.51 os: "NixOS, Niri" role: Portable dev laptop. Third pi machine. On-the-go + at home. tech: pi, Neovim, Home Manager. ThinkPad L14 Gen 2 AMD. hardware: cpu: model: "AMD Ryzen 5 PRO 5650U with Radeon Graphics" cores: 6 threads: 12 ram: total_gb: 14 gpu: disks: - device: /dev/nvme0n1 size: 238G mountpoint: / network: - sam-4screen-desktop has ssh keys to sam-ubuntu1 and nixos-desktop - "Gitea: Docker on .35 (gitea-server-1 + gitea-db-1) — web .35:3001, SSH .35:2222. pi-config repo: ssh://git@gitea.lab.audasmedia.com.au:2222/sam/pi-config.git" - "pi: Nix-managed pi-coding-agent 0.82.1 on all three (uniform); pi-tool-display global; pi-lsp-extension per-project" - "Each machine has its own ~/.agents clone of pi-config — a push from .27 does NOT auto-update .13/.51" - "DNS: Pi Hole on sam-ubuntu1 in docker" - "Reverse Proxy: Caddy on sam-ubuntu1 in docker" - "pihole main: sam-ubuntu1" - "pihole redundancy: nixos-desktop" - "Router Main: 192.168.20.1" - "Router Second: 192.168.20.254" - "Proxmox VE host: 192.168.20.28 (web UI :8006); PBS: 192.168.20.48 (:8007)" - "External IP: 144.6.86.11 (NOT 173.231.229.92 — that's InMotion's server)" - "Website: Audasmedia.com.au redirects to local *.lab.audasmedia.com.au" --- # System Architect Sam's NixOS multi-machine infrastructure reference. ## Machines | Machine | IP | Type | OS | Role | |---------|-----|------|-----|------| | sam-4screen-desktop | 192.168.20.27 | Desktop | NixOS + Niri | Main dev machine | | nixos-desktop | 192.168.20.13 | Desktop | NixOS + Niri | Second dev, web facing, Docker services | | sam-thinkpad | 192.168.20.51 | Laptop | NixOS + Niri | Portable dev laptop | | sam-ubuntu1 | 192.168.20.35 | VM | Ubuntu | Docker host for home network services | | home-assistant | 192.168.20.30 | VM | HA OS | Home automation | | file-server | 192.168.20.23 | VM | - | File server | | proxmox-backup | 192.168.20.48 | VM | PBS | Proxmox backup server | | proxmox | 192.168.20.28 | Host | Proxmox VE | Hypervisor — hosts all VMs (.23/.30/.35/.48), web UI :8006 | | skinnyspeakers | 192.168.20.24 | Pi | Raspbian 12 | Speaker/audio client (Snapcast?) — identified 2026-08-29 | ## Network - DNS: Pi Hole on sam-ubuntu1 (Docker), redundancy on nixos-desktop - Reverse Proxy: Caddy on sam-ubuntu1 - Proxmox VE host: 192.168.20.28 (web UI :8006); PBS: 192.168.20.48 (:8007) - Router: 192.168.20.1 (main), 192.168.20.254 (secondary) - External IP: 144.6.86.11 (NOT 173.231.229.92 — that's InMotion's server) - Website: audasmedia.com.au → *.lab.audasmedia.com.au ## Web Deploy Sync (.27 → .13) - **Manual lsyncd** (not a service): config `~/.config/lsyncd/lsyncd.conf.lua` on .27 → rsync+ssh to `.13` `/var/www/` (`delete = true`). - Sites: `sprinklers` (zola/sprinkler/public), `sam-developer` + `sam-devops` (home_network/web_sites/*/dist) — see config for the full list. - Permissions (.13): web folders use NixOS `users` group — new folders need `sudo chown -R sam:users /var/www/`. - Secrets: `~/.config/environment.d/10-secrets.conf` (env keys, kept out of the git-tracked Nix store). Full hardware specs are in the frontmatter metadata. ## Resource Pressure on .13 (verified 2026-10-05) `.13` is **memory-bound, not CPU-bound**. Load average is ~0.27 on 12 threads, but the 8.8 GB swap partition is **81% full**. Before proposing anything that adds load to `.13`, check the swap. Full detail: Obsidian → `300 areas/360 Dev-Ops Network Computers/Resource Use — .13 CPU & RAM.md`. | Consumer | RAM + swap | Notes | |---|---|---| | KDE Plasma session (~30 processes) | ~2.4 GB | Software rendering (GPU dead) + 28-day uptime | | Docker containers (all) | ~3.5 GB RSS | `voice_whisper` 877 MB is the largest | | `litellm` + `headroom` | ~1.05 GB *swap* | Idle; both fully paged out; redundant with OmniRoute | | Dead Airflow logs | 24 GB *disk* | `/home/sam/deployment/airflow/logs` — nothing depends on it | **Must stay on `.13`:** Pi-hole `:53`, OmniRoute `:20128/20129` (all pi LLM traffic), Mosquitto `:1883` (Home Assistant on `.30`), the Borg backup target on `/mnt/ubuntu_storage_3TB` (`.27` pushes daily at 04:00), Caddy `:8000` + `/var/www`. **Corrections applied 2026-10-05:** `.13` runs **KDE Plasma 6**, not Niri. `.13` disk device letters were wrong (root is `/dev/sda2`). Home Assistant is on **`.30`, not `.35`** (`.35` is `sam-ubuntu1`, the Caddy/docker app host). Pi-hole primary is **`.35`**; `.13` is the replica (confirmed from `nebulasync`: `PRIMARY=http://192.168.20.35`, `REPLICAS=http://192.168.20.13`). ## Pi Agent (uniform across machines) - **Binary**: nixpkgs `pi-coding-agent` 0.82.1 in `home.packages` on .27/.13/.51 (Nix-managed; npx wrapper + npm-global install removed 2026-08-05). Updates = nixpkgs flake bump + rebuild. - **Assets**: `~/.agents` (git → Gitea `pi-config` on .35). Each machine has its OWN clone — update each machine's repo individually (`git -C ~/.agents pull`). - **Global settings**: `~/.pi/agent/settings.json` — home.nix-managed on .27/.51; plain file on .13 (`chmod 600`, keys inline, outside any git repo). Same content: Gitea source (tavily-search, pi-config, pi-tool-display), skills (nixos-workflow), themes, prompts. - **pi-tool-display**: global renderer (0 tools, 0 token cost). **pi-lsp-extension**: per-project via `/config-add ext pi-lsp-extension`. See `Obsidian → 350 AI → Pi Agent Extensions & Skills.md` for details.