我們現在想實現多個容器數據同步，比如多個Mysql數據同步，掛載了的容器被稱爲父容器。
現在我們先把容器1起一下，用我們上個文章創建的wang/centos
[root@wangstudy _data]# docker run -it --name docker1 wang/centos
[root@5cd8cba5139d /]# ls -l
total 56
lrwxrwxrwx 1 root root 7 May 11 2019 bin -> usr/bin
drwxr-xr-x 5 root root 360 Jun 3 10:43 dev
drwxr-xr-x 1 root root 4096 Jun 3 10:43 etc
drwxr-xr-x 2 root root 4096 May 11 2019 home
lrwxrwxrwx 1 root root 7 May 11 2019 lib -> usr/lib
lrwxrwxrwx 1 root root 9 May 11 2019 lib64 -> usr/lib64
drwx------ 2 root root 4096 Jan 13 21:48 lost+found
drwxr-xr-x 2 root root 4096 May 11 2019 media
drwxr-xr-x 2 root root 4096 May 11 2019 mnt
drwxr-xr-x 2 root root 4096 May 11 2019 opt
dr-xr-xr-x 118 root root 0 Jun 3 10:43 proc
dr-xr-x--- 2 root root 4096 Jan 13 21:49 root
drwxr-xr-x 11 root root 4096 Jan 13 21:49 run
lrwxrwxrwx 1 root root 8 May 11 2019 sbin -> usr/sbin
drwxr-xr-x 2 root root 4096 May 11 2019 srv
dr-xr-xr-x 13 root root 0 May 30 08:43 sys
drwxrwxrwt 7 root root 4096 Jan 13 21:49 tmp
drwxr-xr-x 12 root root 4096 Jan 13 21:49 usr
drwxr-xr-x 20 root root 4096 Jan 13 21:49 var
drwxr-xr-x 2 root root 4096 Jun 3 10:43 volume01
drwxr-xr-x 2 root root 4096 Jun 3 10:43 volume02
我們再起一個容器docker2，然後去掛載docker1，可以看到docker2也有這兩個掛載文件
[root@wangstudy ~]#docker run -it --name docker2 --volume from docker1 wang/centos
[root@8f9b5d163b8f /]# ls -l
total 56
lrwxrwxrwx 1 root root 7 May 11 2019 bin -> usr/bin
drwxr-xr-x 5 root root 360 Jun 3 10:43 dev
drwxr-xr-x 1 root root 4096 Jun 3 10:43 etc
drwxr-xr-x 2 root root 4096 May 11 2019 home
lrwxrwxrwx 1 root root 7 May 11 2019 lib -> usr/lib
lrwxrwxrwx 1 root root 9 May 11 2019 lib64 -> usr/lib64
drwx------ 2 root root 4096 Jan 13 21:48 lost+found
drwxr-xr-x 2 root root 4096 May 11 2019 media
drwxr-xr-x 2 root root 4096 May 11 2019 mnt
drwxr-xr-x 2 root root 4096 May 11 2019 opt
dr-xr-xr-x 118 root root 0 Jun 3 10:43 proc
dr-xr-x--- 2 root root 4096 Jan 13 21:49 root
drwxr-xr-x 11 root root 4096 Jan 13 21:49 run
lrwxrwxrwx 1 root root 8 May 11 2019 sbin -> usr/sbin
drwxr-xr-x 2 root root 4096 May 11 2019 srv
dr-xr-xr-x 13 root root 0 May 30 08:43 sys
drwxrwxrwt 7 root root 4096 Jan 13 21:49 tmp
drwxr-xr-x 12 root root 4096 Jan 13 21:49 usr
drwxr-xr-x 20 root root 4096 Jan 13 21:49 var
drwxr-xr-x 2 root root 4096 Jun 3 10:43 volume01
drwxr-xr-x 2 root root 4096 Jun 3 10:43 volume02
我們現在往docker1容器里加文件，來看docker2是否會存在文件,發現存在，所有掛載成功。
[root@wangstudy ~]# docker attach 5cd8cba5139d
[root@5cd8cba5139d /]# cd volume01
[root@5cd8cba5139d volume01]# ls
[root@5cd8cba5139d volume01]# touch docker01
[root@5cd8cba5139d volume01]# ls
docker01
[root@5cd8cba5139d volume01]# read escape sequence
[root@wangstudy ~]# docker attach 8f9b5d163b8f
[root@8f9b5d163b8f /]# cd volume01
[root@8f9b5d163b8f volume01]# ls
docker01
現在我們再創建docker3去掛載docker1，同樣存在文件
[root@wangstudy ~]# docker run -it --name docker3 --volumes-from docker1 wang/centos
[root@7cc24ec1b075 /]# cd volume01
[root@7cc24ec1b075 volume01]# ls
docker01
如此，就實現了容器間數據共享，就算刪掉docker1，數據依舊還在，相當於實現了數據備份。
[root@wangstudy ~]# docker stop 5cd8cba5139d
5cd8cba5139d
[root@wangstudy ~]# docker rm 5cd8cba5139d
5cd8cba5139d
[root@wangstudy ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7cc24ec1b075 wang/centos "/bin/sh -c /bin/bash" 6 minutes ago Up 6 minutes docker3
8f9b5d163b8f wang/centos "/bin/sh -c /bin/bash" 19 minutes ago Up 19 minutes docker2
[root@wangstudy ~]# docker attach 8f9b5d163b8f
[root@8f9b5d163b8f volume01]# ls
docker01 docker03
[root@8f9b5d163b8f volume01]#