Docker映像存储在主机上的什么位置？

本文翻译自：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. 我设法在目录/var/lib/docker/containers containers下找到了容器，但是找不到图像。

What are the directories and files under /var/lib/docker ? /var/lib/docker下的目录和文件是什么？

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#1楼

参考：https://stackoom.com/question/1IhrD/Docker映像存储在主机上的什么位置

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#2楼

The images are stored in /var/lib/docker/graph/<id>/layer . 图像存储在/var/lib/docker/graph/<id>/layer 。

Note that images are just diffs from the parent image. 请注意，图像只是与父图像的差异。 The parent ID is stored with the image's metadata /var/lib/docker/graph/<id>/json . 父ID与图像的元数据/var/lib/docker/graph/<id>/json存储在一起。

When you docker run an image. 当您docker run映像时。 AUFS will 'merge' all layers into one usable file system. AUFS将所有层“合并”到一个可用的文件系统中。

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#3楼

On Ubuntu you can "play" with images running 在Ubuntu上，您可以“播放”正在运行的图像

sudo baobab /var/lib/docker

Actually, images are stored within /var/lib/docker/aufs/diff 实际上，图像存储在/var/lib/docker/aufs/diff

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#4楼

In the special case of Mac OS X or Windows, using boot2docker, your Docker images are stored within a VirtualBox VM managed by boot2docker. 在Mac OS X或Windows的特殊情况下，使用boot2docker，则将Docker映像存储在由boot2docker管理的VirtualBox VM中。

This VM will be stored in normal place of VirtualBox images: 该虚拟机将存储在VirtualBox映像的常规位置：

OS X: ~/VirtualBox VMs/boot2docker-vm OS X： ~/VirtualBox VMs/boot2docker-vm

Windows: %USERPROFILE%/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): 您可以通过运行来重置它（警告：这将破坏您到目前为止构建并下载的所有图像）：

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: 如果在构建/调试构建时没有大量有用的--rm选项的情况下保留了大量中间映像，则此功能特别有用，在此引用以供参考：使用：

docker build -t webapp --rm=true --force-rm=true .

instead of: 代替：

docker build -t webapp .

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#5楼

The contents of the /var/lib/docker directory vary depending on the driver Docker is using for storage . /var/lib/docker目录的内容根据Docker用于存储的驱动程序而有所不同。

By default this will be aufs but can fall back to overlay , overlay2 , btrfs , devicemapper or zfs depending on your kernel support. 默认情况下，它将是aufs但根据您的内核支持，可以回落到overlay ， overlay2 ， btrfs ， devicemapper或zfs 。 In most places this will be aufs but the RedHats went with devicemapper . 在大多数地方，这将是aufs但是RedHats与devicemapper一起使用 。

You can manually set the storage driver with the -s or --storage-driver= option to the Docker daemon . 您可以使用Docker守护程序的-s或--storage-driver=选项手动设置存储驱动程序 。

• /var/lib/docker/{driver-name} will contain the driver specific storage for contents of the images. /var/lib/docker/{driver-name}将包含驱动程序特定的图像内容存储。
• /var/lib/docker/graph/<id> now only contains metadata about the image, in the json and layersize files. /var/lib/docker/graph/<id>现在仅在json和layersize文件中包含有关图像的元数据。

In the case of aufs : 对于aufs ：

• /var/lib/docker/aufs/diff/<id> has the file contents of the images. /var/lib/docker/aufs/diff/<id>具有图像的文件内容。
• /var/lib/docker/repositories-aufs is a JSON file containing local image information. /var/lib/docker/repositories-aufs是一个包含本地图像信息的JSON文件。 This can be viewed with the command docker images . 可以使用docker images命令查看。

In the case of devicemapper : 对于devicemapper ：

• /var/lib/docker/devicemapper/devicemapper/data stores the images /var/lib/docker/devicemapper/devicemapper/data存储映像
• /var/lib/docker/devicemapper/devicemapper/metadata the metadata /var/lib/docker/devicemapper/devicemapper/metadata元数据
• Note these files are thin provisioned "sparse" files so aren't as big as they seem. 请注意，这些文件是精简配置的“稀疏”文件，因此没有看起来那么大。

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#6楼

Actually, Docker images are stored in two files as shown by following command 实际上，Docker映像存储在两个文件中，如以下命令所示

$ docker info

Data file: /var/lib/docker/devicemapper/devicemapper/data 数据文件： /var/lib/docker/devicemapper/devicemapper/data

Metadata file: /var/lib/docker/devicemapper/devicemapper/metadata 元数据文件： /var/lib/docker/devicemapper/devicemapper/metadata