A 17-hour calibration tap on 2026-10-29/30 wrote ZERO bytes: the runner booted
FRANK_ARCHON_IMAGE (1.8.1) for every mode, and RADIANCE_CALIB_DIR/TOKENS only
arms the expert tap on the 1.2.x line. 1.8.1 still carries the plugin strings and
the "calibration wrote layer Hessians" message, /health answered, /stats showed
1,700 documents and 118 tok/s, and nothing anywhere said the tap was dead.
Four gates, each with the measurement that motivated it:
- CALIB_IMAGE pins the 1.2.0 digest for calib mode (stilldeadcode/radiance
@sha256:665775ed…), overridable only by naming --image deliberately. Proven by
the engagement test: `calibration wrote layer Hessians after 10207 tokens`.
- The tap dir's filesystem must have >= 60 GiB free (Q38_CALIB_MIN_FREE_MIB).
One seal wrote 39.4 GiB in seconds; pointed at a 37 GiB root it filled the
filesystem to zero and every later write came back short.
- restore() kills orphaned `radiance` processes still holding /dev/kfd before it
starts the service. `podman rm -f` does not kill the engine: an orphan made
production's ar_oneshot_2rank_wht6 init fail `device error`, and the unit
restarted 100 times with /health never answering.
- FRANK_QWEN38_CALIB_DIR / Q38_WINDOW_TRASH_ROOT make the tap dir and the bank
target configurable, so the tap lives on /mnt/entropy instead of the root fs.
Frank
b4a1e6069e