Docker一般默认安装在/var/lib/docker目录下，对于云主机或云服务器默认系统盘不大的情况很不友好，动不动就是overlay占用很大空间。
将Docker默认安装位置迁移分为一下几步：
一、找到Docker默认安装位置
1 [root@XXXXXXX ~]# docker info 2 Client: 3 Context: default 4 Debug Mode: false 5 Plugins: 6 app: Docker App (Docker Inc., v0.9.1-beta3) 7 buildx: Docker Buildx (Docker Inc., v0.8.2-docker) 8 scan: Docker Scan (Docker Inc., v0.17.0) 9 10 Server: 11 Containers: 14 12 Running: 8 13 Paused: 0 14 Stopped: 6 15 Images: 14 16 Server Version: 20.10.17 17 Storage Driver: overlay2 18 Backing Filesystem: extfs 19 Supports d_type: true 20 Native Overlay Diff: true 21 userxattr: false 22 Logging Driver: json-file 23 Cgroup Driver: cgroupfs 24 Cgroup Version: 1 25 Plugins: 26 Volume: local 27 Network: bridge host ipvlan macvlan null overlay 28 Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog 29 Swarm: inactive 30 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc 31 Default Runtime: runc 32 Init Binary: docker-init 33 containerd version: XXXX2954828e7c7c9b6e0ea9b0c02b01407XXX 34 runc version: v1.1.2-0-ga916309 35 init version: de40ad0 36 Security Options: 37 seccomp 38 Profile: default 39 Kernel Version: 3.10.0-1062.18.1.el7.x86_64 40 Operating System: CentOS Linux 7 (Core) 41 OSType: linux 42 Architecture: x86_64 43 CPUs: 2 44 Total Memory: 15.51GiB 45 Name: XXXX2tbvXXXZ 46 ID: IPOO:XXXO:Q7NC:QI3B:3XXX:HXXO:GIIF:XCMS:ELT3:GXXX:B6XG:6XXX 47 Docker Root Dir: /var/lib/docker 48 Debug Mode: false 49 Registry: https://index.docker.io/v1/ 50 Labels: 51 Experimental: false 52 Insecure Registries: 53 127.0.0.0/8 54 Live Restore Enabled: false
其中Docker Root Dir: /var/lib/docker就是安装目录。
二、创建或修改daemon.json配置文件
daemon.json 是 Docker 的配置文件，初始安装是没有被创建的，官网介绍说需要我们自己创建，它的目录在/etc/docker下。
下面是关于daemon.json文件配置参数的一个简单说明（注意：不是所有都要，后面有示例）
1 {
2 "authorization-plugins": [],
3 "data-root": "", # 设置docker运行时的根目录
4 "dns": [], # 设置容器的DNS地址
5 "dns-opts": [], # 设置容器的/etc/resolv.conf文件
6 "dns-search": [],
7 "exec-opts": [],
8 "exec-root": "",
9 "experimental": false,
10 "features": {},
11 "storage-driver": "",
12 "storage-opts": [],
13 "labels": [],
14 "live-restore": true,
15 "log-driver": "json-file",
16 "log-opts": {
17 "max-size": "10m",
18 "max-files":"5",
19 "labels": "somelabel",
20 "env": "os,customer"
21 },
22 "mtu": 0,
23 "pidfile": "", # 设置docker守护进程的PID文件
24 "cluster-store": "",
25 "cluster-store-opts": {},
26 "cluster-advertise": "",
27 "max-concurrent-downloads": 3,
28 "max-concurrent-uploads": 5,
29 "default-shm-size": "64M",
30 "shutdown-timeout": 15,
31 "debug": true, # 是否以debug模式启动docker
32 "hosts": [], # 设置容器的hosts
33 "log-level": "",
34 "tls": true,
35 "tlsverify": true,
36 "tlscacert": "",
37 "tlscert": "",
38 "tlskey": "",
39 "swarm-default-advertise-addr": "",
40 "api-cors-header": "",
41 "selinux-enabled": false, # 设置是否支持SELinux
42 "userns-remap": "",
43 "group": "",
44 "cgroup-parent": "",
45 "default-ulimits": {
46 "nofile": {
47 "Name": "nofile",
48 "Hard": 64000,
49 "Soft": 64000
50 }
51 },
52 "init": false,
53 "init-path": "/usr/libexec/docker-init",
54 "ipv6": false,
55 "iptables": false,
56 "ip-forward": false,
57 "ip-masq": false,
58 "userland-proxy": false,
59 "userland-proxy-path": "/usr/libexec/docker-proxy",
60 "ip": "0.0.0.0",
61 "bridge": "",
62 "bip": "",
63 "fixed-cidr": "",
64 "fixed-cidr-v6": "",
65 "default-gateway": "",
66 "default-gateway-v6": "",
67 "icc": false,
68 "raw-logs": false,
69 "allow-nondistributable-artifacts": [],
70 "registry-mirrors": [], # 设置镜像加速地址
71 "seccomp-profile": "",
72 "insecure-registries": [], # 设置docker的私有仓库地址
73 "no-new-privileges": false,
74 "default-runtime": "runc",
75 "oom-score-adjust": -500,
76 "node-generic-resources": ["NVIDIA-GPU=UUID1", "NVIDIA-GPU=UUID2"],
77 "runtimes": {
78 "cc-runtime": {
79 "path": "/usr/bin/cc-runtime"
80 },
81 "custom": {
82 "path": "/usr/local/bin/my-runc-replacement",
83 "runtimeArgs": [
84 "--debug"
85 ]
86 }
87 },
88 "default-address-pools":[{"base":"172.80.0.0/16","size":24},
89 {"base":"172.90.0.0/16","size":24}]
90 }
接下来创建一个daemon.json配置文件，注意，如果/etc下没有docker目录一定要先创建。
1 mkdir /etc/docker
然后，vi编辑器创建文件
1 vi /etc/docker/daemon.json
文件内容如下（/data/docker是我要迁移过去的文件夹）：
{
"data-root": "/data/docker", # 填写你想迁移过去的文件夹路径
"log-driver": "json-file",
"log-opts": {
"cache-disabled": "false",
"cache-max-file": "5",
"cache-max-size": "20m",
"cache-compress": "true",
"max-size": "200m",
"max-file": "5"
},
"storage-driver": "overlay2",
"registry-mirrors": [
"https://hub-mirror.c.163.com",
"https://mirror.baidubce.com"
],
"insecure-registries": []
}
ESC，:wq保存。这里千万注意，json文件中参数名前面的空格一定要用制表符，不要用4个空格，否则后面docker服务启动会失败！
三、停止docker服务，将现有的默认Docker安装路径下的文件复制到将要迁移的文件夹下
这里，我要迁移的目标是/data/docker
1 systemctl stop docker 2 cp -r /var/lib/docker /data # 这里要用/data而不是/data/docker是因为复制过去会自动生成一个docker文件夹
四、停止docker服务，并重启服务
1 systemctl daemon-reload 2 systemctl restart docker
大功告成！
标签：false,default,max,默认,CentOS7,json,Docker,docker From： https://www.cnblogs.com/sheng9hhd/p/18113176