Configuration

This guide covers essential configuration options for optimizing Ollama performance, managing resources, and customizing model behavior.

Environment Variables

Ollama's behavior can be controlled using environment variables, which can be set before running the ollama command:

# Example: Setting environment variables
export OLLAMA_MODELS=/path/to/models
export OLLAMA_HOST=0.0.0.0:11434
ollama serve

Core Environment Variables

Variable	Description	Default
OLLAMA_HOST	Network address to listen on	127.0.0.1:11434
OLLAMA_MODELS	Directory to store models	~/.ollama/models
OLLAMA_KEEP_ALIVE	Keep models loaded in memory (minutes)	5
OLLAMA_TIMEOUT	Request timeout (seconds)	30

Performance Environment Variables

Variable	Description	Default
CUDA_VISIBLE_DEVICES	Control which NVIDIA GPUs are used	All available
OLLAMA_NUM_GPU	Number of GPUs to use	All available
OLLAMA_NUM_THREAD	Number of CPU threads to use	Auto-detected
OLLAMA_COMPUTE_TYPE	Compute type for inference (float16, float32, auto)	auto

Security Environment Variables

Variable	Description	Default
OLLAMA_ORIGINS	CORS origins to allow	All (*)
OLLAMA_TLS_CERT	Path to TLS certificate	None
OLLAMA_TLS_KEY	Path to TLS key	None

Configuration File

Ollama supports a JSON configuration file located at ~/.ollama/config.json:

{
  "host": "127.0.0.1:11434",
  "models_path": "/path/to/models",
  "keep_alive": 15,
  "num_threads": 12,
  "compute_type": "float16",
  "tls": {
    "cert": "/path/to/cert.pem",
    "key": "/path/to/key.pem"
  }
}

GPU Configuration

NVIDIA GPU Setup

For NVIDIA GPUs, ensure you have the CUDA toolkit installed:

# Check CUDA availability
nvidia-smi

# Set specific GPUs (e.g., use only GPU 0)
export CUDA_VISIBLE_DEVICES=0
ollama serve

AMD ROCm Setup

For AMD GPUs with ROCm support:

# Check ROCm installation
rocminfo

# Set environment variables for AMD GPUs
export HSA_OVERRIDE_GFX_VERSION=10.3.0
export OLLAMA_COMPUTE_TYPE=float16
ollama serve

Intel GPU Setup

For Intel Arc GPUs:

# Install Intel oneAPI toolkit
sudo apt-get install intel-oneapi-runtime-opencl

# Enable Intel GPU acceleration
export NEOCommandLine="-cl-intel-greater-than-4GB-buffer-required"
export OLLAMA_COMPUTE_TYPE=float16
ollama serve

Memory Management

Optimize Ollama's memory usage with these settings:

# Reduce model context size (trade-off between memory and context length)
ollama run mistral:latest -c 4096

# Unload models when not in use (in minutes)
export OLLAMA_KEEP_ALIVE=0

Network Configuration

Binding to External Interfaces

To make Ollama accessible from other machines on your network:

export OLLAMA_HOST=0.0.0.0:11434
ollama serve

Configuring TLS

For secure communications:

# Generate self-signed certificate
openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes

# Enable TLS
export OLLAMA_TLS_CERT=/path/to/cert.pem
export OLLAMA_TLS_KEY=/path/to/key.pem
ollama serve

Model Configuration with Modelfiles

Create custom models with Modelfiles:

# Example Modelfile
FROM mistral:latest
PARAMETER temperature 0.7
PARAMETER top_p 0.9
SYSTEM You are a helpful DevOps assistant.

# Save as Modelfile and create the model
ollama create devops-assistant -f ./Modelfile

Modelfile Commands

Command	Description	Example
FROM	Base model	FROM mistral:latest
PARAMETER	Set inference parameter	PARAMETER temperature 0.7
SYSTEM	Set system message	SYSTEM You are a helpful assistant
TEMPLATE	Define prompt template	TEMPLATE <s>{{.System}}</s>{{.Prompt}}
LICENSE	Specify model license	LICENSE MIT

Real-world Configuration Examples

High-Performance Server Setup

For a dedicated Ollama server with multiple powerful GPUs:

# Create a systemd service file
sudo nano /etc/systemd/system/ollama.service

[Unit]
Description=Ollama Service
After=network.target

[Service]
Environment="OLLAMA_HOST=0.0.0.0:11434"
Environment="OLLAMA_MODELS=/mnt/storage/ollama/models"
Environment="OLLAMA_KEEP_ALIVE=60"
Environment="OLLAMA_NUM_THREAD=32"
ExecStart=/usr/local/bin/ollama serve
Restart=always
RestartSec=5
User=ollama
Group=ollama

[Install]
WantedBy=multi-user.target

# Enable and start the service
sudo systemctl daemon-reload
sudo systemctl enable ollama
sudo systemctl start ollama

Low Resource Environment

For systems with limited resources:

# Minimal configuration for resource-constrained systems
export OLLAMA_KEEP_ALIVE=0
export OLLAMA_NUM_THREAD=4
export OLLAMA_COMPUTE_TYPE=float32

# Run smaller models
ollama pull tinyllama
ollama run tinyllama -c 2048

API Configuration

Configure the Ollama API for integration with other tools:

# Start the API server
ollama serve

# Test API access
curl http://localhost:11434/api/tags

API Rate Limiting

Add rate limiting with a reverse proxy like Nginx:

http {
    limit_req_zone $binary_remote_addr zone=ollama_api:10m rate=5r/s;
    
    server {
        listen 80;
        server_name ollama.example.com;
        
        location / {
            limit_req zone=ollama_api burst=10 nodelay;
            proxy_pass http://127.0.0.1:11434;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
        }
    }
}

Multi-User Setup

For shared environments, use Docker with multiple containers:

# docker-compose.yml for multi-user setup
version: '3'

services:
  ollama-user1:
    image: ollama/ollama:latest
    ports:
      - "11435:11434"
    volumes:
      - ollama_user1:/root/.ollama
    environment:
      - OLLAMA_KEEP_ALIVE=30
      - OLLAMA_HOST=0.0.0.0:11434
    
  ollama-user2:
    image: ollama/ollama:latest
    ports:
      - "11436:11434"
    volumes:
      - ollama_user2:/root/.ollama
    environment:
      - OLLAMA_KEEP_ALIVE=30
      - OLLAMA_HOST=0.0.0.0:11434

volumes:
  ollama_user1:
  ollama_user2:

Troubleshooting Configuration Issues

Issue	Possible Solution
Model loads slowly	Check OLLAMA_NUM_THREAD and OLLAMA_COMPUTE_TYPE
High memory usage	Reduce context size or use smaller models
Network timeout	Increase OLLAMA_TIMEOUT or check firewall
Permission errors	Check file ownership of OLLAMA_MODELS directory

Next Steps

After configuring Ollama:

• Explore available models
• Set up GPU acceleration
• Try the Open WebUI for a graphical interface
• Integrate Ollama in your DevOps workflow