# Fine-tune with NeMo

> Use NVIDIA NeMo to fine-tune models locally

## Table of Contents

- [Overview](#overview)
- [Instructions](#instructions)
- [Troubleshooting](#troubleshooting)

---

## Overview

## Basic idea

This playbook guides you through setting up and using NVIDIA NeMo AutoModel for fine-tuning large language models and vision-language models on NVIDIA Spark devices. NeMo AutoModel provides GPU-accelerated, end-to-end training for Hugging Face models with native PyTorch support, enabling instant fine-tuning without conversion delays. The framework supports distributed training across single GPU to multi-node clusters, with optimized kernels and memory-efficient recipes specifically designed for ARM64 architecture and Blackwell GPU systems.

## What you'll accomplish

You'll establish a complete fine-tuning environment for large language models (1-70B parameters) and vision-language models using NeMo AutoModel on your NVIDIA Spark device. By the end, you'll have a working installation that supports parameter-efficient fine-tuning (PEFT), supervised fine-tuning (SFT), and distributed training capabilities with FP8 precision optimizations, all while maintaining compatibility with the Hugging Face ecosystem.

## What to know before starting

- Working in Linux terminal environments and SSH connections
- Basic understanding of Python virtual environments and package management
- Familiarity with GPU computing concepts and CUDA toolkit usage
- Experience with containerized workflows and Docker/Podman operations
- Understanding of machine learning model training concepts and fine-tuning workflows

## Prerequisites

- NVIDIA Spark device with Blackwell architecture GPU access
- CUDA toolkit 12.0+ installed and configured: `nvcc --version`
- Python 3.10+ environment available: `python3 --version`
- Minimum 32GB system RAM for efficient model loading and training
- Active internet connection for downloading models and packages
- Git installed for repository cloning: `git --version`
- SSH access to your NVIDIA Spark device configured

## Ancillary files

All necessary files for the playbook can be found [here on GitHub](https://github.com/NVIDIA-NeMo/Automodel)

## Time & risk

* **Duration:** 45-90 minutes for complete setup and initial model fine-tuning
* **Risks:** Model downloads can be large (several GB), ARM64 package compatibility issues may require troubleshooting, distributed training setup complexity increases with multi-node configurations
* **Rollback:** Virtual environments can be completely removed; no system-level changes are made to the host system beyond package installations.

## Instructions

## Step 1. Verify system requirements

Check your NVIDIA Spark device meets the prerequisites for [NeMo AutoModel](https://github.com/NVIDIA-NeMo/Automodel) installation. This step runs on the host system to confirm CUDA toolkit availability and Python version compatibility.

```bash
## Verify CUDA installation
nvcc --version

## Check Python version (3.10+ required)
python3 --version

## Verify GPU accessibility
nvidia-smi

## Check available system memory
free -h
```

## Step 2. Get the container image

```bash
docker pull nvcr.io/nvidia/pytorch:25.08-py3
```

## Step 3. Launch Docker

```bash
docker run \
  --gpus all \
  --ulimit memlock=-1 \
  -it --ulimit stack=67108864 \
  --entrypoint /usr/bin/bash \
  --rm nvcr.io/nvidia/pytorch:25.08-py3
```

## Step 4. Install package management tools

Install `uv` for efficient package management and virtual environment isolation. NeMo AutoModel uses `uv` for dependency management and automatic environment handling.

```bash
## Install uv package manager
pip3 install uv

## Verify installation
uv --version
```

**If system installation fails:**

```bash
## Install for current user only
pip3 install --user uv

## Add to PATH if needed
export PATH="$HOME/.local/bin:$PATH"
```

## Step 5. Clone NeMo AutoModel repository

Clone the official NeMo AutoModel repository to access recipes and examples. This provides ready-to-use training configurations for various model types and training scenarios.

```bash
## Clone the repository
git clone https://github.com/NVIDIA-NeMo/Automodel.git

## Navigate to the repository
cd Automodel
```

## Step 6. Install NeMo AutoModel

Set up the virtual environment and install NeMo AutoModel. Choose between wheel package installation for stability or source installation for latest features.

**Install from wheel package (recommended):**

```bash
## Initialize virtual environment
uv venv --system-site-packages

## Install packages with uv
uv sync --inexact --frozen --all-extras \
  --no-install-package torch \
  --no-install-package torchvision \
  --no-install-package triton \
  --no-install-package nvidia-cublas-cu12 \
  --no-install-package nvidia-cuda-cupti-cu12 \
  --no-install-package nvidia-cuda-nvrtc-cu12 \
  --no-install-package nvidia-cuda-runtime-cu12 \
  --no-install-package nvidia-cudnn-cu12 \
  --no-install-package nvidia-cufft-cu12 \
  --no-install-package nvidia-cufile-cu12 \
  --no-install-package nvidia-curand-cu12 \
  --no-install-package nvidia-cusolver-cu12 \
  --no-install-package nvidia-cusparse-cu12 \
  --no-install-package nvidia-cusparselt-cu12 \
  --no-install-package nvidia-nccl-cu12 \
  --no-install-package transformer-engine \
  --no-install-package nvidia-modelopt \
  --no-install-package nvidia-modelopt-core \
  --no-install-package flash-attn \
  --no-install-package transformer-engine-cu12 \
  --no-install-package transformer-engine-torch

## Install bitsandbytes
CMAKE_ARGS="-DCOMPUTE_BACKEND=cuda -DCOMPUTE_CAPABILITY=80;86;87;89;90" \
CMAKE_BUILD_PARALLEL_LEVEL=8 \
uv pip install --no-deps git+https://github.com/bitsandbytes-foundation/bitsandbytes.git@50be19c39698e038a1604daf3e1b939c9ac1c342
```

## Step 7. Verify installation

Confirm NeMo AutoModel is properly installed and accessible. This step validates the installation and checks for any missing dependencies.

```bash
## Test NeMo AutoModel import
uv run --frozen --no-sync python -c "import nemo_automodel; print('✅ NeMo AutoModel ready')"

## Check available examples
ls -la examples/

## Below is an example of the expected output (username and domain-users are placeholders).
## $ ls -la examples/
## total 36
## drwxr-xr-x  9 username domain-users 4096 Oct 16 14:52 .
## drwxr-xr-x 16 username domain-users 4096 Oct 16 14:52 ..
## drwxr-xr-x  3 username domain-users 4096 Oct 16 14:52 benchmark
## drwxr-xr-x  3 username domain-users 4096 Oct 16 14:52 diffusion
## drwxr-xr-x 20 username domain-users 4096 Oct 16 14:52 llm_finetune
## drwxr-xr-x  3 username domain-users 4096 Oct 14 09:27 llm_kd
## drwxr-xr-x  2 username domain-users 4096 Oct 16 14:52 llm_pretrain
## drwxr-xr-x  6 username domain-users 4096 Oct 14 09:27 vlm_finetune
## drwxr-xr-x  2 username domain-users 4096 Oct 14 09:27 vlm_generate
```

## Step 8. Explore available examples

Review the pre-configured training recipes available for different model types and training scenarios. These recipes provide optimized configurations for ARM64 and Blackwell architecture.

```bash
## List LLM fine-tuning examples
ls examples/llm_finetune/

## View example recipe configuration
cat examples/llm_finetune/finetune.py | head -20
```

## Step 9. Run sample fine-tuning
The following commands show how to perform full fine-tuning (SFT), parameter-efficient fine-tuning (PEFT) with LoRA and QLoRA.

First, export your HF_TOKEN so that gated models can be downloaded.

```bash
## Run basic LLM fine-tuning example
export HF_TOKEN=<your_huggingface_token>
```
> [!NOTE]
> Replace `<your_huggingface_token>` with your personal Hugging Face access token. A valid token is required to download any gated model.
>
> - Generate a token: [Hugging Face tokens](https://huggingface.co/settings/tokens), guide available [here](https://huggingface.co/docs/hub/en/security-tokens).
> - Request and receive access on each model's page (and accept license/terms) before attempting downloads.
>   - Llama-3.1-8B: [meta-llama/Llama-3.1-8B](https://huggingface.co/meta-llama/Llama-3.1-8B)
>   - Qwen3-8B: [Qwen/Qwen3-8B](https://huggingface.co/Qwen/Qwen3-8B)
>   - Mixtral-8x7B: [mistralai/Mixtral-8x7B](https://huggingface.co/mistralai/Mixtral-8x7B)
>
> The same steps apply for any other gated model you use: visit its model card on Hugging Face, request access, accept the license, and wait for approval.

**LoRA fine-tuning example:**

Execute a basic fine-tuning example to validate the complete setup. This demonstrates parameter-efficient fine-tuning using a small model suitable for testing.
For the examples below, we are using YAML for configuration, and parameter overrides are passed as command line arguments.

```bash
## Run basic LLM fine-tuning example
uv run --frozen --no-sync \
examples/llm_finetune/finetune.py \
-c examples/llm_finetune/llama3_2/llama3_2_1b_squad_peft.yaml \
--model.pretrained_model_name_or_path meta-llama/Llama-3.1-8B \
--packed_sequence.packed_sequence_size 1024 \
--step_scheduler.max_steps 100
```

These overrides ensure the Llama-3.1-8B LoRA run behaves as expected:
- `--model.pretrained_model_name_or_path`: selects the Llama-3.1-8B model to fine-tune from the Hugging Face model hub (weights fetched via your Hugging Face token).
- `--packed_sequence.packed_sequence_size`: sets the packed sequence size to 1024 to enable packed sequence training.
- `--step_scheduler.max_steps`: sets the maximum number of training steps. We set it to 100 for demonstation purposes, please adjust this based on your needs.


**QLoRA fine-tuning example:**

We can use QLoRA to fine-tune large models in a memory-efficient manner.

```bash
uv run --frozen --no-sync \
examples/llm_finetune/finetune.py \
-c examples/llm_finetune/llama3_1/llama3_1_8b_squad_qlora.yaml \
--model.pretrained_model_name_or_path meta-llama/Meta-Llama-3-70B \
--loss_fn._target_ nemo_automodel.components.loss.te_parallel_ce.TEParallelCrossEntropy \
--step_scheduler.local_batch_size 1 \
--packed_sequence.packed_sequence_size 1024 \
--step_scheduler.max_steps 100
```

These overrides ensure the 70B QLoRA run behaves as expected:
- `--model.pretrained_model_name_or_path`: selects the 70B base model to fine-tune (weights fetched via your Hugging Face token).
- `--loss_fn._target_`: uses the TransformerEngine-parallel cross-entropy loss variant compatible with tensor-parallel training for large LLMs.
- `--step_scheduler.local_batch_size`: sets the per-GPU micro-batch size to 1 to fit 70B in memory; overall effective batch size is still driven by gradient accumulation and data/tensor parallel settings from the recipe. 
- `--step_scheduler.max_steps`: sets the maximum number of training steps. We set it to 100 for demonstation purposes, please adjust this based on your needs.
- `--packed_sequence.packed_sequence_size`: sets the packed sequence size to 1024 to enable packed sequence training.

**Full Fine-tuning example:**

Once inside the `Automodel` directory you cloned from GitHub, run:

```bash
uv run --frozen --no-sync \
examples/llm_finetune/finetune.py \
-c examples/llm_finetune/qwen/qwen3_8b_squad_spark.yaml \
--model.pretrained_model_name_or_path Qwen/Qwen3-8B \
--step_scheduler.local_batch_size 1 \
--step_scheduler.max_steps 100 \
--packed_sequence.packed_sequence_size 1024
```
These overrides ensure the Qwen3-8B SFT run behaves as expected:
- `--model.pretrained_model_name_or_path`: selects the Qwen/Qwen3-8B model to fine-tune from the Hugging Face model hub (weights fetched via your Hugging Face token). Adjust this if you want to fine-tune a different model.
- `--step_scheduler.max_steps`: sets the maximum number of training steps. We set it to 100 for demonstation purposes, please adjust this based on your needs.
- `--step_scheduler.local_batch_size`: sets the per-GPU micro-batch size to 1 to fit in memory; overall effective batch size is still driven by gradient accumulation and data/tensor parallel settings from the recipe.


## Step 10. Validate successful training completion

Validate the fine-tuned model by inspecting artifacts contained in the checkpoint directory.

```bash
## Inspect logs and checkpoint output.
## The LATEST is a symlink pointing to the latest checkpoint.
## The checkpoint is the one that was saved during training.
## below is an example of the expected output (username and domain-users are placeholders).
ls -lah checkpoints/LATEST/

## $ ls -lah checkpoints/LATEST/
## total 32K
## drwxr-xr-x 6 username domain-users 4.0K Oct 16 22:33 .
## drwxr-xr-x 4 username domain-users 4.0K Oct 16 22:33 ..
## -rw-r--r-- 1 username domain-users 1.6K Oct 16 22:33 config.yaml
## drwxr-xr-x 2 username domain-users 4.0K Oct 16 22:33 dataloader
## drwxr-xr-x 2 username domain-users 4.0K Oct 16 22:33 model
## drwxr-xr-x 2 username domain-users 4.0K Oct 16 22:33 optim
## drwxr-xr-x 2 username domain-users 4.0K Oct 16 22:33 rng
## -rw-r--r-- 1 username domain-users 1.3K Oct 16 22:33 step_scheduler.pt
```

## Step 11. Cleanup and rollback (Optional)

Remove the installation and restore the original environment if needed. These commands safely remove all installed components.

> [!WARNING]
> This will delete all virtual environments and downloaded models. Ensure you have backed up any important training checkpoints.

```bash
## Remove virtual environment
rm -rf .venv

## Remove cloned repository
cd ..
rm -rf Automodel

## Remove uv (if installed with --user)
pip3 uninstall uv

## Clear Python cache
rm -rf ~/.cache/pip
```
## Step 12. Optional: Publish your fine-tuned model checkpoint on Hugging Face Hub

Publish your fine-tuned model checkpoint on Hugging Face Hub.
> [!NOTE]
> This is an optional step and is not required for using the fine-tuned model.
> It is useful if you want to share your fine-tuned model with others or use it in other projects.
> You can also use the fine-tuned model in other projects by cloning the repository and using the checkpoint.
> To use the fine-tuned model in other projects, you need to have the Hugging Face CLI installed.
> You can install the Hugging Face CLI by running `pip install huggingface-cli`.
> For more information, please refer to the [Hugging Face CLI documentation](https://huggingface.co/docs/huggingface_hub/en/guides/cli).

> [!TIP]
> You can use the `hf` command to upload the fine-tuned model checkpoint to Hugging Face Hub.
> For more information, please refer to the [Hugging Face CLI documentation](https://huggingface.co/docs/huggingface_hub/en/guides/cli).

```bash
## Publish the fine-tuned model checkpoint to Hugging Face Hub
## will be published under the namespace <your_huggingface_username>/my-cool-model, adjust name as needed.
hf upload my-cool-model checkpoints/LATEST/model
```

> [!TIP]
> The above command can fail if you don't have write permissions to the Hugging Face Hub, with the HF_TOKEN you used.
> Sample error message:
> ```bash
> akoumparouli@1604ab7-lcedt:/mnt/4tb/auto/Automodel8$ hf upload my-cool-model checkpoints/LATEST/model
> Traceback (most recent call last):
>   File "/home/akoumparouli/.local/lib/python3.10/site-packages/huggingface_hub/utils/_http.py", line 409, in hf_raise_for_status
>     response.raise_for_status()
>   File "/home/akoumparouli/.local/lib/python3.10/site-packages/requests/models.py", line 1024, in raise_for_status
>     raise HTTPError(http_error_msg, response=self)
> requests.exceptions.HTTPError: 403 Client Error: Forbidden for url: https://huggingface.co/api/repos/create
> ```
> To fix this, you need to create an access token with *write* permissions, please see the Hugging Face guide [here](https://huggingface.co/docs/hub/en/security-tokens) for instructions.

## Step 12. Next steps

Begin using NeMo AutoModel for your specific fine-tuning tasks. Start with provided recipes and customize based on your model requirements and dataset.

```bash
## Copy a recipe for customization
cp recipes/llm_finetune/finetune.py my_custom_training.py

## Edit configuration for your specific model and data
## Then run: uv run my_custom_training.py
```

Explore the [NeMo AutoModel GitHub repository](https://github.com/NVIDIA-NeMo/Automodel) for more recipes, documentation, and community examples. Consider setting up custom datasets, experimenting with different model architectures, and scaling to multi-node distributed training for larger models.

## Troubleshooting

| Symptom | Cause | Fix |
|---------|--------|-----|
| `nvcc: command not found` | CUDA toolkit not in PATH | Add CUDA toolkit to PATH: `export PATH=/usr/local/cuda/bin:$PATH` |
| `pip install uv` permission denied | System-level pip restrictions | Use `pip3 install --user uv` and update PATH |
| GPU not detected in training | CUDA driver/runtime mismatch | Verify driver compatibility: `nvidia-smi` and reinstall CUDA if needed |
| Out of memory during training | Model too large for available GPU memory | Reduce batch size, enable gradient checkpointing, or use model parallelism |
| ARM64 package compatibility issues | Package not available for ARM architecture | Use source installation or build from source with ARM64 flags |
| Cannot access gated repo for URL | Certain HuggingFace models have restricted access | Regenerate your [HuggingFace token](https://huggingface.co/docs/hub/en/security-tokens); and request access to the [gated model](https://huggingface.co/docs/hub/en/models-gated#customize-requested-information) on your web browser |

> [!NOTE]
> DGX Spark uses a Unified Memory Architecture (UMA), which enables dynamic memory sharing between the GPU and CPU.
> With many applications still updating to take advantage of UMA, you may encounter memory issues even when within
> the memory capacity of DGX Spark. If that happens, manually flush the buffer cache with:
```bash
sudo sh -c 'sync; echo 3 > /proc/sys/vm/drop_caches'
```
