dgx-spark-playbooks/nvidia/pytorch-fine-tune

Fine-tune with Pytorch

Use Pytorch to fine-tune models locally

Table of Contents

• Overview
• Instructions
• Run on two Sparks
  • Step 1. Configure network connectivity
  • Step 2. Configure Docker permissions
  • Step 3. Install NVIDIA Container Toolkit & setup Docker environment
  • Step 4. Enable resource advertising
  • Step 5. Initialize Docker Swarm
  • Step 6. Join worker nodes and deploy
  • Step 7. Find your Docker container ID
  • Step 9. Adapt the configuration files
  • Step 10. Run finetuning scripts
  • Step 14. Cleanup and rollback
• Troubleshooting

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Overview

Basic idea

This playbook guides you through setting up and using Pytorch for fine-tuning large language models on NVIDIA Spark devices.

What you'll accomplish

You'll establish a complete fine-tuning environment for large language models (1-70B parameters) on your NVIDIA Spark device. By the end, you'll have a working installation that supports parameter-efficient fine-tuning (PEFT) and supervised fine-tuning (SFT).

What to know before starting

• Previous experience with fine-tuning in Pytorch
• Working with Docker

Prerequisites

Recipes are specifically for DIGITS SPARK. Please make sure that OS and drivers are latest.

Ancillary files

ALl files required for fine-tuning are included in the folder in the GitHub repository here.

Time & risk

• Time estimate: 30-45 mins for setup and runing fine-tuning. Fine-tuning run time varies depending on model size
• Risks: Model downloads can be large (several GB), ARM64 package compatibility issues may require troubleshooting.

Instructions

Step 1. Configure Docker permissions

To easily manage containers without sudo, you must be in the docker group. If you choose to skip this step, you will need to run Docker commands with sudo.

Open a new terminal and test Docker access. In the terminal, run:

docker ps

If you see a permission denied error (something like permission denied while trying to connect to the Docker daemon socket), add your user to the docker group so that you don't need to run the command with sudo .

sudo usermod -aG docker $USER
newgrp docker

Step 2. Pull the latest Pytorch container

docker pull nvcr.io/nvidia/pytorch:25.09-py3

Step 3. Launch Docker

docker run --gpus all -it --rm --ipc=host \
-v $HOME/.cache/huggingface:/root/.cache/huggingface \
-v ${PWD}:/workspace -w /workspace \
nvcr.io/nvidia/pytorch:25.09-py3

Step 4. Install dependencies inside the container

pip install transformers peft datasets "trl==0.19.1" "bitsandbytes==0.48"

Step 5: Authenticate with Huggingface

huggingface-cli login
##<input your huggingface token.
##<Enter n for git credential>

Step 6: Clone the git repo with fine-tuning recipes

git clone https://github.com/NVIDIA/dgx-spark-playbooks
cd dgx-spark-playbooks/nvidia/pytorch-fine-tune/assets

Step7: Run the fine-tuning recipes

To run LoRA on Llama3-8B use the following command:

python Llama3_8B_LoRA_finetuning.py

To run qLoRA fine-tuning on llama3-70B use the following command:

python Llama3_70B_qLoRA_finetuning.py

To run full fine-tuning on llama3-3B use the following command:

python Llama3_3B_full_finetuning.py

Run on two Sparks

Step 1. Configure network connectivity

Follow the network setup instructions from the Connect two Sparks playbook to establish connectivity between your DGX Spark nodes.

This includes:

• Physical QSFP cable connection
• Network interface configuration (automatic or manual IP assignment)
• Passwordless SSH setup
• Network connectivity verification

Step 2. Configure Docker permissions

To easily manage containers without sudo, you must be in the docker group. If you choose to skip this step, you will need to run Docker commands with sudo.

Open a new terminal and test Docker access. In the terminal, run:

docker ps

If you see a permission denied error (something like permission denied while trying to connect to the Docker daemon socket), add your user to the docker group so that you don't need to run the command with sudo .

sudo usermod -aG docker $USER
newgrp docker

Step 3. Install NVIDIA Container Toolkit & setup Docker environment

Ensure the NVIDIA drivers and the NVIDIA Container Toolkit are installed on each node (both manager and workers) that will provide GPU resources. This package enables Docker containers to access the host's GPU hardware. Ensure you complete the installation steps, including the Docker configuration for NVIDIA Container Toolkit.

Step 4. Enable resource advertising

First, find your GPU UUID by running:

nvidia-smi -a | grep UUID

Next, modify the Docker daemon configuration to advertise the GPU to Swarm. Edit /etc/docker/daemon.json:

sudo nano /etc/docker/daemon.json

Add or modify the file to include the nvidia runtime and GPU UUID (replace GPU-45cbf7b3-f919-7228-7a26-b06628ebefa1 with your actual GPU UUID):

{
  "runtimes": {
    "nvidia": {
      "path": "nvidia-container-runtime",
      "runtimeArgs": []
    }
  },
  "default-runtime": "nvidia",
  "node-generic-resources": [
    "NVIDIA_GPU=GPU-45cbf7b3-f919-7228-7a26-b06628ebefa1"
    ]
}

Modify the NVIDIA Container Runtime to advertise the GPUs to the Swarm by uncommenting the swarm-resource line in the config.toml file. You can do this either with your preferred text editor (e.g., vim, nano...) or with the following command:

sudo sed -i 's/^#\s*\(swarm-resource\s*=\s*".*"\)/\1/' /etc/nvidia-container-runtime/config.toml

Finally, restart the Docker daemon to apply all changes:

sudo systemctl restart docker

Repeat these steps on all nodes.

Step 5. Initialize Docker Swarm

On whichever node you want to use as primary, run the following swarm initialization command

docker swarm init --advertise-addr $(ip -o -4 addr show enp1s0f0np0 | awk '{print $4}' | cut -d/ -f1) $(ip -o -4 addr show enp1s0f1np1 | awk '{print $4}' | cut -d/ -f1)

The typical output of the above would be similar to the following:

Swarm initialized: current node (node-id) is now a manager.

To add a worker to this swarm, run the following command:

    docker swarm join --token <worker-token> <advertise-addr>:<port>

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

Step 6. Join worker nodes and deploy

Now we can proceed with setting up the worker nodes of your cluster. Repeat these steps on all worker nodes.

Run the command suggested by the docker swarm init on each worker node to join the Docker swarm

docker swarm join --token <worker-token> <advertise-addr>:<port>

On both nodes, download the pytorch-ft-entrypoint.sh script into the directory containing your finetuning scripts and configuration files and run the following command to make it executable:

chmod +x $PWD/pytorch-ft-entrypoint.sh

On your primary node, deploy the Finetuning multi-node stack by downloading the docker-compose.yml file into the same directory as in the previous step and running the following command:

docker stack deploy -c $PWD/docker-compose.yml finetuning-multinode

Note

Ensure you download both files into the same directory from which you are running the command.

You can verify the status of your worker nodes using the following

docker stack ps finetuning-multinode

If everything is healthy, you should see a similar output to the following:

nvidia@spark-1b3b:~$ docker stack ps finetuning-multinode
ID             NAME                                IMAGE                              NODE         DESIRED STATE   CURRENT STATE            ERROR     PORTS
vlun7z9cacf9   finetuning-multinode_finetunine.1   nvcr.io/nvidia/pytorch:25.10-py3   spark-1d84   Running         Starting 2 seconds ago             
tjl49zicvxoi   finetuning-multinode_finetunine.2   nvcr.io/nvidia/pytorch:25.10-py3   spark-1b3b   Running         Starting 2 seconds ago             

Note

If your "Current state" is not "Running", see troubleshooting section for more information.

Step 7. Find your Docker container ID

You can use docker ps to find your Docker container ID. You can save the container ID in a variable as shown below. Run this command on both nodes.

export FINETUNING_CONTAINER=$(docker ps -q -f name=finetuning-multinode)

Step 9. Adapt the configuration files

For multi-node runs, we provide 2 configuration files:

• config_finetuning.yaml used for full finetuning of Llama3 3B.
• config_fsdp_lora.yaml used for finetuning with LoRa and FSDP of Llama3 8B and Llama3 70B.

These configuration files need to be adapted:

• Set machine_rank on each of your nodes according to its rank. Your master node should have a rank 0. The second node has a rank 1.
• Set the correct IP address of your master node. Use ifconfig to find the correct value for your CX-7 IP address.
• Set a port number that can be used on your main node.

The fields that need to be filled in your YAML files:

machine_rank: 0
main_process_ip: < TODO: specify IP >
main_process_port: < TODO: specify port >

Step 10. Run finetuning scripts

Once you successfully run the previous steps, you can use one of the run-multi-llama_* scripts for finetuning. Here is an example for Llama3 70B using LoRa for finetuning and FSDP2.

## Need to specify huggingface token for model download.
export HF_TOKEN=<your-huggingface-token>

docker exec \
  -e HF_TOKEN=$HF_TOKEN \
  -it $FINETUNING_CONTAINER bash -c '
  bash /workspace/install-requirements;
  accelerate launch --config_file=/workspace/configs/config_fsdp_lora.yaml /workspace/Llama3_70B_LoRA_finetuning.py'

Step 14. Cleanup and rollback

Stop and remove containers by using the following command on the leader node:

docker stack rm finetuning-multinode

Remove downloaded models to free disk space:

rm -rf $HOME/.cache/huggingface/hub/models--meta-llama* $HOME/.cache/huggingface/hub/datasets*

Troubleshooting

Symptom	Cause	Fix
Cannot access gated repo for URL	Certain HuggingFace models have restricted access	Regenerate your HuggingFace token; and request access to the gated model 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:

sudo sh -c 'sync; echo 3 > /proc/sys/vm/drop_caches'