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+---
+type: report
+date: 2026-10-09
+---
+# Headless: No Desktop, No Sound Server
+
+## Why
+
+The car unit has no display of its own; the display is the tablet app. Anything graphical on the Orin
+uses unified memory, which the voice stack (GPT-SoVITS TTS, Whisper ASR) needs more.
+
+## Result
+
+| Item | State |
+|------|-------|
+| Default target | `multi-user.target` (was `graphical.target`): GDM, Xorg and GNOME no longer start |
+| Local console | `getty@tty1` enabled, so a text login appears on a directly attached monitor/keyboard |
+| Sound servers | PulseAudio and PipeWire disabled for all users. **ALSA kept**: devices are still there for mic capture |
+| Camera | `nvargus-daemon` kept (used by `camera-webui` and the later vision service) |
+| Memory | "used" went from 1206 MB to 1005 MB (~200 MB) on an idle system (GDM greeter only, nobody logged in graphically) |
+
+Per-process RSS for the desktop added up to ~550 MB, but that counts shared pages once per process. The `free` difference is the real saving.
+
+## Commands
+
+```
+sudo systemctl set-default multi-user.target
+sudo systemctl enable getty@tty1
+sudo systemctl --global disable pulseaudio.socket pulseaudio.service \
+    pipewire.socket pipewire.service pipewire-media-session.service
+sudo systemctl isolate multi-user.target      # apply now, without a reboot
+```
+
+`disable` rather than `mask`: nothing is removed, and each step reverses cleanly.
+
+```
+sudo systemctl set-default graphical.target
+sudo systemctl --global enable pulseaudio.socket pulseaudio.service \
+    pipewire.socket pipewire.service pipewire-media-session.service
+```
+
+To start the desktop once without changing the default: `sudo systemctl start gdm`.
+
+## Audio
+
+Project Yukart's plan keeps the **microphone on the Orin** (Whisper) and sends **TTS to the tablet** as chunked
+utterances. Neither needs a desktop sound server:
+
+- capture: read the ALSA device directly (`arecord -l` lists it; a USB mic adds its own card);
+- playback on the Orin itself isn't needed (only HDMI is present: `card 0: HDA`).
+
+If a service later needs PipeWire anyway, run it for that service's user with `loginctl enable-linger <user>`,
+so it starts at boot without a login session. Don't re-enable it globally.
+
+## Side effects seen when switching live
+
+`systemctl isolate` re-ran two NVIDIA oneshot units, which then failed because their setup was already done:
+
+- `nvzramconfig`: `mkswap: /dev/zram5 is mounted`. All six zram swap devices are active, so nothing is missing.
+- `nv_nvsciipc_init`: exits 1 on re-run.
+
+Both run only once on a normal boot. **To check at the next boot:** `systemctl --failed` should list neither.
+
+## Unrelated, pre-existing
+
+`logrotate.service` fails every night: `stat of /data/logging-volume/*.log failed: Permission denied`.
+`/etc/logrotate.d/jetson-logging` (package `nvidia-jetson-services`) rotates as user `logging`, but `/data` is `drwx------ root`.
+Harmless because nothing logs there. Left as is, since it's a package-owned file.