llm-inference-multimodel: add Qwen2.5-14B shadow instance (port 8002, gated off — VRAM co-residency not yet confirmed)

- New llama-server-qwen systemd unit template, gated by llm_qwen_service_enabled (default false)
- Idempotent GGUF download task (bartowski Qwen2.5-14B-Instruct-Q5_K_M, stat-guarded)
- Launch flags per local-llm-64k-context-recommendation.md: ctx-size 65536, flash-attn, q8_0 KV cache, batch 2048/ubatch 512, jinja, parallel 1
- verify.yml only starts/verifies the qwen unit when llm_qwen_service_enabled=true
- README: documents live VRAM gate finding (nvidia-smi 2026-08-06: Phi-4+Mistral already ~16.6/24GB, ~7.5GB free -- insufficient for Qwen weights concurrently) and options
- Does NOT touch llama-server-aux (8000) or llama-server-toolcall (8001) service state

ansible/roles/llm-inference-multimodel/tasks/models.yml

@@ -97,3 +97,28 @@
     group: "{{ llm_service_user }}"
     mode: "0644"
   become: true
+
+# --- Shadow model (Qwen2.5-14B-Instruct Q5_K_M, port 8002) --------------------
+# Downloaded unconditionally (so the ~10.5GB file is staged ahead of any VRAM
+# decision) — only the *service start* is gated by llm_qwen_service_enabled
+# (see verify.yml / VRAM gate note in defaults/main.yml).
+
+- name: Check if Qwen shadow model GGUF already exists
+  ansible.builtin.stat:
+    path: "{{ llm_qwen_model_path }}"
+  register: llm_qwen_model_stat
+
+- name: Download Qwen2.5-14B-Instruct-Q5_K_M GGUF (bartowski quant)
+  ansible.builtin.get_url:
+    url: "{{ llm_qwen_model_url }}"
+    dest: "{{ llm_qwen_model_path }}"
+    headers:
+      Authorization: "Bearer {{ llm_hf_token }}"
+    owner: "{{ llm_service_user }}"
+    group: "{{ llm_service_user }}"
+    mode: "0644"
+    timeout: 7200
+    force: false
+  become: true
+  no_log: true
+  when: not llm_qwen_model_stat.stat.exists or (llm_qwen_model_stat.stat.size | int) < (llm_qwen_model_min_bytes | int)

ansible/roles/llm-inference-multimodel/tasks/systemd.yml

@@ -41,6 +41,18 @@
   notify:
     - reload systemd
 
+- name: Deploy llama-server-qwen systemd unit (shadow, port 8002)
+  ansible.builtin.template:
+    src: llama-server-qwen.service.j2
+    dest: "/etc/systemd/system/{{ llm_qwen_service_name }}.service"
+    owner: root
+    group: root
+    mode: "0644"
+  become: true
+  register: llm_qwen_unit_deployed
+  notify:
+    - reload systemd
+
 - name: Flush handlers so daemon-reload lands before any later phase acts on unit state
   ansible.builtin.meta: flush_handlers
 

ansible/roles/llm-inference-multimodel/tasks/verify.yml

@@ -166,6 +166,51 @@
       - "Design estimate (plan §1):  aux ~{{ llm_aux_expected_vram_gb }}GB + toolcall ~{{ llm_toolcall_expected_vram_gb }}GB = ~{{ llm_combined_expected_vram_gb }}GB / {{ llm_gpu_total_vram_gb }}GB total"
       - "If measured usage exceeds ~23.5GB or is within ~0.5GB of the 24GB card limit, treat as the OOM-risk trigger condition from plan §6 — do not leave both services running unattended without confirming headroom."
 
+- name: Enable llama-server-qwen and start/restart (GATED — only if llm_qwen_service_enabled)
+  ansible.builtin.systemd:
+    name: "{{ llm_qwen_service_name }}"
+    state: "{{ 'restarted' if (llm_qwen_unit_deployed.changed | default(false)) else 'started' }}"
+    enabled: true
+    daemon_reload: true
+  become: true
+  when: llm_qwen_service_enabled | default(false)
+
+- name: NOTE if Qwen shadow unit was skipped due to VRAM gate
+  ansible.builtin.debug:
+    msg: >-
+      llama-server-qwen unit deployed to disk but NOT started
+      (llm_qwen_service_enabled=false). See VRAM gate note in
+      defaults/main.yml / deployment report — Phi-4(8000)+Mistral(8001)
+      already use ~16.6GB/24GB, leaving ~7.5GB free, insufficient for
+      Qwen2.5-14B's ~10-12GB weight footprint concurrently. Resolve before
+      setting llm_qwen_service_enabled: true.
+  when: not (llm_qwen_service_enabled | default(false))
+
+- name: Wait for Qwen shadow instance API to become available (only if enabled)
+  ansible.builtin.uri:
+    url: "http://{{ llm_bind_address }}:{{ llm_qwen_port }}/health"
+    status_code: 200
+  register: llm_qwen_health
+  retries: 24
+  delay: 10
+  until: llm_qwen_health.status == 200
+  when: llm_qwen_service_enabled | default(false)
+
+- name: Smoke-test — Qwen shadow instance model listing + n_ctx verification (only if enabled)
+  ansible.builtin.uri:
+    url: "http://{{ llm_bind_address }}:{{ llm_qwen_port }}/v1/models"
+    status_code: 200
+    return_content: true
+  register: llm_qwen_models
+  when: llm_qwen_service_enabled | default(false)
+
+- name: Report Qwen shadow instance served model + verified n_ctx (only if enabled)
+  ansible.builtin.debug:
+    msg:
+      - "Qwen shadow (:{{ llm_qwen_port }}) serving: {{ llm_qwen_models.json.data | map(attribute='id') | list }}"
+      - "Verified n_ctx (must be >= 64000, not just requested): {{ llm_qwen_models.json.data | map(attribute='meta') | map(attribute='n_ctx') | list }}"
+  when: llm_qwen_service_enabled | default(false)
+
 - name: Check for OOM-kill events related to llama-server in dmesg (best-effort, read-only)
   ansible.builtin.shell:
     cmd: "dmesg | grep -i 'llama-server' | grep -i -E 'oom|killed' || true"