Docker System Cleanup & Disk Space

Checking Disk Usage

Start by understanding what Docker is consuming:

docker system df

Output shows usage for images, containers, volumes, and build cache:

TYPE            TOTAL   ACTIVE  SIZE      RECLAIMABLE
Images          45      12      12.5GB    8.2GB (65%)
Containers      15      3       256MB     200MB (78%)
Local Volumes   8       4       3.1GB     1.5GB (48%)
Build Cache     120     0       5.8GB     5.8GB (100%)

The Nuclear Option: docker system prune

# Remove all stopped containers, unused networks, dangling images, and build cache
docker system prune

# Also remove ALL unused images (not just dangling)
docker system prune -a

# Also remove volumes (DANGEROUS: deletes data!)
docker system prune -a --volumes

# Skip the confirmation prompt
docker system prune -a -f

Targeted Cleanup

For more control, prune specific resource types:

# Remove stopped containers
docker container prune

# Remove dangling images
docker image prune

# Remove ALL unused images
docker image prune -a

# Remove unused volumes
docker volume prune

# Remove unused networks
docker network prune

# Remove build cache
docker builder prune

# Remove build cache older than 24h
docker builder prune --filter "until=24h"

Automated Cleanup Scripts

#!/bin/bash
# Weekly cleanup script
echo "Docker disk usage before cleanup:"
docker system df
docker container prune -f
docker image prune -a -f --filter "until=168h"
docker volume prune -f
docker builder prune -f --filter "until=168h"
echo "Docker disk usage after cleanup:"
docker system df