Where are Docker images stored on the host machine?
I managed to find the containers under directory /var/lib/docker/containers , but I can't find the images.
What are the directories and files under /var/lib/docker ?
The contents of the /var/lib/docker directory vary depending on the driver Docker is using for storage.
By default this will be aufs but can fall back to overlay , overlay2 , btrfs , devicemapper or zfs depending on your kernel support. In most places this will be aufs but the RedHats went with devicemapper .
You can manually set the storage driver with the -s or --storage-driver= option to the Docker daemon.
/var/lib/docker/{driver-name} will contain the driver specific storage for contents of the images. /var/lib/docker/graph/<id> now only contains metadata about the image, in the json and layersize files. In the case of aufs :
/var/lib/docker/aufs/diff/<id> has the file contents of the images. /var/lib/docker/repositories-aufs is a JSON file containing local image information. This can be viewed with the command docker images . In the case of devicemapper :
/var/lib/docker/devicemapper/devicemapper/data stores the images /var/lib/docker/devicemapper/devicemapper/metadata the metadata 当使用Docker for Mac应用程序时，看起来这些容器存储在位于以下位置的虚拟机中：
~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/Docker.qcow2
In the special case of Mac OS X or Windows, using boot2docker, your Docker images are stored within a VirtualBox VM managed by boot2docker.
This VM will be stored in normal place of VirtualBox images:
OS X: ~/VirtualBox VMs/boot2docker-vm
Windows: %USERPROFILE%/VirtualBox VMs/boot2docker-vm
You can reset it by running (WARNING: This will destroy all images you've built and downloaded so far):
boot2docker down
boot2docker destroy
boot2docker init
boot2docker up
This is especially useful if you kept tons of intermediate images when building / debugging a build without the useful --rm options, I quote them here for reference: Use:
docker build -t webapp --rm=true --force-rm=true .
instead of:
docker build -t webapp .