docker修改默认存储目录

docker 默认存储映像、卷和集群状态等持久化数据的路径是/var/lib/docker。
那么如何修改默认的存储目录呢？
1、停止docker服务，创建新的存储目录，并将原来的文件迁移过去

root@nianyu-virtual-machine:~# systemctl status docker
● docker.service - Docker Application Container Engine
     Loaded: loaded (/etc/systemd/system/docker.service; enabled; vendor preset: enabled)
     Active: active (running) since Sun 2023-02-05 19:35:31 CST; 1h 25min ago
       Docs: https://docs.docker.com
   Main PID: 883 (dockerd)
      Tasks: 17
     Memory: 102.0M
        CPU: 6.137s
     CGroup: /system.slice/docker.service
             ├─ 883 /usr/bin/dockerd
             └─1194 containerd --config /var/run/docker/containerd/containerd.toml --log-level info
root@nianyu-virtual-machine:~# docker info | grep Root
 Docker Root Dir: /var/lib/docker
root@nianyu-virtual-machine:~# systemctl stop docker

2、重新设置 Docker Root Dir
修改/etc/docker/daemon.json

{
  "data-root": "/mnt/docker"
}

3、启动服务

root@nianyu-virtual-machine:~# systemctl start docker

4、检查 Docker Root Dir 的值是否已修改

docker info | grep Root