# Shift 2026-09-25 (day) — MiMo-V2.6-Pro-RL 8× Spark bring-up

## Context

User: new model to try on 8 nodes — rhys101's SGLang variant of the NVIDIA
forum thread 384064 (github.com/rhys101/MiMo-V2.6-Pro-RL-Spark-8, build a14).
Also: user reverted dgx1's HF symlink to the NAS (NAS is back, 7.4T with data),
and wiped all docker images from dgx1.

## Power + state survey

- All 8 nodes powered on (`sm121 power on --cluster 8nodes-switch`, HA relays
  incl. sw6_mt for the MikroTik). NAS read speed single-stream ~171 MB/s.
- Symlink matrix: dgx1 → NAS (user-fixed); dgx2–4 → hf-local (as before);
  dgx5–8 → NAS (never changed). `--hf-cache` flag (new, `51b7404`) makes the
  symlink question moot for a given serve.
- Images: dgx1 wiped (only sglang dev-qwen38-next-local left); dgx2 the
  richest (r35/r38/r39/lab/karmic); dgx5–8 stale (r27/r35/r36/r37 + dsv41).

## MiMo bring-up (rhys101 repo @ 2f3e5fd, build a14)

- Model already on the NAS: `XiaomiMiMo/MiMo-V2.6-Pro-RL` @ `73875d00` (the
  exact pinned revision), 146 top-level files, `dflash/` subfolder present.
  Not on any node locally (535 GB/rank would not fit on dgx1–3/5 anyway).
- Vendored the build tree into `docker-images/mimo26-spark/` (Dockerfile +
  12 patches + third_party/b12x + runtime + fp8 tile tables + versions.env
  pinning the base digest + versions.lock.json). `d5663ec`.
- Recipe `mimo26-pro-rl-8x`: sglang, TP8 (launcher-generated via
  `distributed_backend = "mp"`), all of the repo's SERVE_ENV flags as `args`,
  `{{dflash}}` path ref for the draft weights, env: SGLANG8_ROCE_ALLREDUCE +
  MIMO26_* + NCCL extras.
- **TOML trap hit (again):** `args = [...]` written after `[[extra_mounts]]`
  parses *into* the extra_mounts table — args silently dropped from the
  docker command. Reordered (bare keys first). Lesson: in recipe TOML, bare
  keys always precede table headers.
- Launcher change: dry-run `--speculative-draft-model-path` now shows the
  raw `{{name}}` placeholder (the old "descriptive path" was substituted
  into the dry-run command, misleading); `substitute_path_refs` skips a
  name==path pair. Removed dead `path_ref_placeholder`.
- Build on dgx4.lan: 14m20s, label `5b92eae1`. Note: `--build-node dgx4`
  does NOT work — node names carry the `.lan` suffix (`dgx4.lan`).
- Sync dgx4→7 peers sequential, ~4.5–6 min each (~35 min total).
- Serve with `--hf-cache /mnt/nas/ai/huggingface --keep`: all 8 containers up
  at 10:44. Model loads **from the NAS per rank** (535 GB each, ~110 MB/s
  per rank, ~1h+ wall). The launcher's 1800 s readiness wait timed out as
  expected (run closed at 1801 s in the ledger — cosmetic; containers stay
  with `--keep`). API came up on its own.

## Smoke (all pass)

- Text + reasoning split: reasoning/content channels clean, `mimo` parsers OK
- Tool call: `get_weather({"city":"Paris"})` exact
- Vision: red/blue 64×32 test → "Red" (correct; image_tokens 8)
- Decode: **~50 tok/s C1** (512 tok, two runs: 50.0 / 49.6) — consistent with
  the repo's a13 C1 per-category range (prose 40.3 … format 99.5, mean 69.1)

## Bench (tool-eval-bench v2.7.0, seed 42, hardmode, perf, c1,2) — 11:54 UTC

**165/176 (94/100 quality, ★★★★★)** — on par with the agent-tuned GLM-5.3
anchors (164–165). Fails: TC-03 (implicit tool need, wrong_args), TC-68
(schema violation, invalid JSON — the recurring one on GLM too). Partials:
TC-21/30/39/52/55/57/60 (mostly "did the work, missed a tool-use nuance" + the
two injection-repro cases). Note: GLM's recurring TC-43/45/51 all PASS here.

Perf (pp2048/tg128): pp 1,687–1,940 t/s; tg c1 50–54 t/s, c2 65–69 t/s
(per-stream); TTFT 1.3 s (d0) … 9.6 s (d8192 c2). Consistent with the repo's
a13 numbers (prefill 1,880 at 5K; C1 mean 69.1 across long 512-tok generations —
ours is 128-tok, DFlash-adaptive, so slightly lower tg is expected).

## Next / open

- Run ledger closed (1801 s timeout); `sm121 stop` still works via labels.
- Candidate follow-ups: node-to-node fan-out of the model for fast re-boots
  (fits only on dgx4/6/7/8 + tight elsewhere); bench (repo's mimobench.py vs
  our tool-eval-bench); C8 aggregate.

## Ops notes

- `--build-node` takes the full node name (`dgx4.lan`), not the bare host.
- A serve that outgrows the 1800 s readiness wait fails the launcher but,
  with `--keep`, leaves the containers running and the API functional.
- py-spy (pip in-container) + `cat /proc/<pid>/io` is the fast way to tell
  "loading slowly" from "stuck" — check the WORKER pid (sglang::scheduler_TP0),
  not the parent (pid 54) which only reads config.