一、环境：
centos7.x系统，已经装好docker-ce服务包

二、查看当前docker的存储路径

[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 ~]$ docker info |grep Dir
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
WARNING: the devicemapper storage-driver is deprecated, and will be removed in a future release.
WARNING: devicemapper: usage of loopback devices is strongly discouraged for production use.
         Use `--storage-opt dm.thinpooldev` to specify a custom block storage device.
 Docker Root Dir: /var/lib/docker              ## docker默认的存储路径

• 三、关闭docker服务

[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 ~]$  systemctl stop docker            ## 关闭docker服务                            
[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 ~]$ systemctl status docker		  ## 查看docker服务状态

• 四、将原有数据迁移至新目录

[root@@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 local]# mkdir /data/service/docker -p
[root@@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 local]# mv /var/lib/docker/* /data/docker/

• 五、修改docker.service配置文件，使用 --graph 参数指定存储位置

[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 local]# vim /usr/lib/systemd/system/docker.service
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock --graph /data/docker

• 六、重新加载配置文件

[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 local]# systemctl daemon-reload

• 七、启动docker服务

[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 local]# systemctl start docker
[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 local]# systemctl enable docker
[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 local]# systemctl status docker

• 八、查看修改是否成功

[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 ~]# docker info | grep Dir
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
WARNING: the devicemapper storage-driver is deprecated, and will be removed in a future release.
WARNING: devicemapper: usage of loopback devices is strongly discouraged for production use.
         Use `--storage-opt dm.thinpooldev` to specify a custom block storage device.
 Docker Root Dir: /data/docker   #查看修改成功
[root@VM-13cb107e-b518-4d7b-a63f-3f0a5499ec76 ~]#