Fix: Docker No Space Left on Device

!Symptoms

• Docker build fails with 'no space left on device'
• Docker pull fails with 'write /var/lib/docker/... no space left on device'
• Containers fail to start with disk space errors
• df -h shows /var/lib/docker partition is full

?Root Causes

• Accumulated unused images, containers, and volumes consuming disk space
• Docker build cache growing unbounded
• Application writing large log files inside the container
• Many dangling images from repeated builds without cleanup
• Small root partition with Docker using the default /var/lib/docker path

#Diagnosis Steps

1. 1Check disk usage: `df -h /var/lib/docker`
2. 2Check Docker disk usage breakdown: `docker system df`
3. 3List large images: `docker images --format '{{.Size}}\t{{.Repository}}:{{.Tag}}' | sort -h`
4. 4Find large volumes: `docker volume ls -q | xargs -I {} docker volume inspect {} --format '{{.Name}} {{.Mountpoint}}'`
5. 5Check for large container logs: `du -sh /var/lib/docker/containers/*/`

>Fix

1. 1Clean unused resources: `docker system prune -a --volumes` (removes all unused data)
2. 2Remove dangling images only: `docker image prune`
3. 3Remove stopped containers: `docker container prune`
4. 4Remove unused volumes: `docker volume prune`
5. 5Limit container log size in daemon.json: `{"log-opts": {"max-size": "10m", "max-file": "3"}}`

*Prevention

• Set up automated Docker cleanup via cron: `docker system prune -f` daily
• Configure log rotation in Docker daemon.json
• Use multi-stage builds to reduce image sizes
• Mount a larger separate disk for /var/lib/docker
• Set up disk usage alerts at 80% threshold

Related Error Messages