Docker Desktop is using 30 GB on your Mac

15 September 2026

Docker Desktop on a Mac runs a Linux virtual machine, and that machine's whole disk is one file: ~/Library/Containers/com.docker.docker/Data/vms/0/data/Docker.raw. Every image you pull, every layer you build, every stopped container and every volume lives inside it.

Why the number looks insane

The file is sparse. Finder and Get Info show its maximum size, which is the disk limit in Docker's settings. On one Mac, Finder said 494 GB while the file really occupied 2.4 GB. du shows the truth:

du -h ~/Library/Containers/com.docker.docker/Data/vms/0/data/Docker.raw

That real number is what counts against your free space, and it shows up inside "System Data" because ~/Library/Containers is hidden.

See what's inside

docker system df

Four lines: images, containers, local volumes, build cache, each with a RECLAIMABLE column. On developer Macs the build cache is often the biggest line. docker system df -v lists every image.

Get the space back

docker image prune -a      # images no container uses
docker builder prune       # build cache
docker container prune     # stopped containers

Or all three at once with docker system prune -a. None of these touch volumes. Volumes are where your databases live; docker volume prune removes the ones no container references, so read the list it prints before you say yes.

The freed space goes back to macOS when Docker trims its disk, which it does on its own a little later. Quitting and reopening Docker Desktop makes it immediate.

Stop it growing back

Docker Desktop → Settings → Resources → Virtual disk limit. After a prune, lower it to something honest. 64 GB is plenty for most people, and Docker can't exceed it.

In ddeploy

Dev Cleanup → Docker row: images no container uses, build cache and stopped containers, sized and preselected. Volumes and running containers are never touched.

More on Mac storage: Old iOS simulator runtimes · Project build folders · Time Machine local snapshots · WhatsApp media on a Mac