Layout on 4x Tesla V100 32GB (PCIe, no NVLink), all TP=1:
GPU0+1 vLLM DeepSeek-R1-Distill-Qwen-32B bnb-nf4 (2 replicas)
GPU2 Ollama ornith:35b + qwen2.5:3b-instruct (co-resident)
GPU3 vLLM Qwen2.5-Math-PRM-7B (reward model)
CPU TEI nomic-embed-text-v2-moe, bge-reranker-base
Volta constraints, each verified against live output rather than config:
- vLLM pinned v0.11.0: sm_70 dropped from CUDA_SUPPORTED_ARCHS at v0.11.1.
- AWQ hard-rejected (needs sm_75). GPTQ passes vLLM's min_capability=60 gate
but is NUMERICALLY WRONG on sm_70 — emits garbage logits. Proven by an fp16
control run producing correct text on an identical backend. bitsandbytes nf4
verified correct by output.
- flashinfer's check_cuda_arch() crashes on any sm_7x (calls .isdigit() on an
int) -> VLLM_USE_FLASHINFER_SAMPLER=0.
- xformers has no sm_70 kernel for V1's paged-attention bias, and V0 was
removed in v0.11.0 -> TRITON_ATTN.
- Ornith is Qwen3.5-MoE hybrid-attention; vLLM added that arch after dropping
Volta, so no build has both -> Ollama, which also multiplexes a second model
on the same card for free.
Cluster prereqs that were absent:
- RuntimeClass nvidia: the Talos toolkit extension registers the containerd
handler but not the k8s object; without it every pod is rejected at admission.
- gpu-system pinned to privileged PSA: a device plugin cannot satisfy the
cluster-default baseline, it must mount hostPath.
- device-plugin affinity=null: the chart requires NFD labels that do not exist
here, so it matched zero nodes and reported desiredNumberScheduled=0 silently.
- Recreate strategy on GPU services: with GPUs allocated exactly 4/4, a
RollingUpdate surge pod has no card and deadlocks the rollout.
- longhorn-llm-local SC (1 replica, strict-local, disk tag llm): the default
3-replica class could not place the volume at all (every control-plane disk
was at its over-provisioning ceiling), and this keeps ~60GB of weights on
worker-1's own NVMe instead of reading them over the network.
deploy-gpu-serving.sh sequences ArgoCD syncs (or helm/kubectl in --manual mode)
and never applies a manifest absent from git; doctor/unstick/teardown stages
exist so this is diagnosable without ad-hoc kubectl archaeology.
Story Crater Bot
4fb1c6feeb