vLLM is an inference engine designed to run large language models efficiently. The key idea is **maximizing throughput and minimizing memory waste** when serving LLMs.
- **PagedAttention**handles long sequences without running out of GPU memory.
- **Continuousbatching** keeps GPUs fully utilized by adding new requests to batches in progress.
- **OpenAI-compatibleAPI** allows applications built for OpenAI to switch to vLLM with minimal changes.
Serve the **Qwen3-235B-A22B-NVFP4** model using vLLM on NVIDIA DGX Station. This 235B parameter model uses NVFP4 quantization and fits entirely in VRAM on the GB300 GPU.
Pull the vLLM container from NGC. Use the **26.01** image on DGX Station; the 25.10 image can fail during engine startup with a FlashInfer buffer overflow on some configurations.
Start the vLLM server with the Qwen3-235B model. This model fits entirely in VRAM on the GB300. On a single-GPU DGX Station, `--gpus all` uses the GB300; if you have multiple GPUs and want to use only the GB300, replace with `--gpus '"device=N"'` where N is the GB300 device ID from `nvidia-smi`.
| "permission denied" when running docker | User not in docker group | Run `sudo usermod -aG docker $USER && newgrp docker` |
| Container fails to start with GPU error | NVIDIA Container Toolkit not configured | Run `nvidia-ctk runtime configure --runtime=docker` and restart Docker |
| "Token is required" or 401 error | Missing HuggingFace token | Ensure `HF_TOKEN` is exported before running docker command |
| Model download hangs or fails | Network or authentication issue | Check internet connection, verify HF_TOKEN is valid |
| CUDA out of memory | Context length too large | Reduce `MAX_MODEL_LEN` or lower `--gpu-memory-utilization` |
| Server not responding on port 8000 | Port already in use | Check with `lsof -i :8000`, use `-p 8001:8000` for different port |
| Model runs on wrong GPU | Default GPU selection | Use `--gpus '"device=0"'` to select specific GPU |
| NGC authentication fails | Invalid or missing credentials | Run `docker login nvcr.io` with NGC API key |
| EngineCore failed / FlashInfer "Buffer overflow when allocating memory for batch_prefill_tmp_v" | Known issue with vLLM 25.10 on some DGX Station setups during CUDA graph capture | Use the **26.01** container image: `nvcr.io/nvidia/vllm:26.01-py3` instead of 25.10. |