How to Fix Docker Daemon Not Running Error Quickly

To fix the docker daemon not running error, start the Docker service using sudo systemctl start docker on Linux or restart Docker Desktop on Windows/Mac. Also, check if Docker is installed correctly and your user has permission to access the Docker socket.

Why This Happens

The Docker daemon is the background service that manages Docker containers. If it is not running, Docker commands fail because they cannot communicate with this service. This often happens if the Docker service is stopped, crashed, or your user lacks permission to access it.

bash

docker ps

Output

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

The Fix

Start the Docker daemon service to fix this error. On Linux, use sudo systemctl start docker. On Windows or Mac, open Docker Desktop and click restart. Also, ensure your user is in the docker group to run Docker commands without sudo.

bash

sudo systemctl start docker
sudo systemctl status docker
sudo usermod -aG docker $USER

Output

● docker.service - Docker Application Container Engine
   Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
   Active: active (running) since Thu 2024-06-01 10:00:00 UTC; 5s ago

# After adding user to docker group, log out and log back in to apply changes.

Prevention

To avoid this error, always ensure Docker starts on boot by enabling the service with sudo systemctl enable docker. Regularly update Docker to the latest stable version. Avoid running Docker commands as root; instead, add your user to the docker group for proper permissions.

bash

sudo systemctl enable docker

Output

Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /lib/systemd/system/docker.service.

Related Errors

Other common Docker errors include:

• Permission denied: Fix by adding your user to the docker group.
• Docker command not found: Install Docker or check your PATH.
• Docker daemon crashes: Check Docker logs with journalctl -u docker for details.

Key Takeaways

Start the Docker daemon service to fix connection errors.

Add your user to the docker group to avoid permission issues.

Enable Docker to start automatically on system boot.

Restart Docker Desktop on Windows/Mac if the daemon stops.

Check Docker logs for detailed error information if problems persist.