默认的存储路径为/var/lib/docker/overlay2/

如果一开始挂载点没有分配好，很容易空间爆炸，所以需要修改存储路径

nano /etc/docker/daemon.json


{
    "registry-mirrors":["https://reg-mirror.qiniu.com/"],
    "storage-driver": "overlay2",
    "data-root": "/home/docker/",
    "storage-opts": [
        "dm.thinpooldev=/dev/mapper/thin-pool",
        "dm.use_deferred_deletion=true",
        "dm.use_deferred_removal=true",
        "dm.basesize=20G",
        "overlay2.override_kernel_check=true",
        "overlay2.size=20G"

    ]
}

如果想保留docker容器内数据，可以先把目录迁移过去再修改路径，修改后重启一次docker就好

新的目录

/home/docker/overlay2/$docker_id/merged