問題描述：
Mac下運行docker容器時，其卷掛載方式與在普通Linux上不同，普通Linux上host與container之間Volume映射關係可參考這篇文章。本文中container的名字是graphite，用命令行查看container的volume掛載情況：
➜ ~ docker inspect graphite
...
...
"Mounts": [
{
"Type": "volume",
"Name": "5676877cb2df79ee28190c1be5f44eb7a4b6cae2b73d4c8d450d5408935015a4",
"Source": "/var/lib/docker/volumes/5676877cb2df79ee28190c1be5f44eb7a4b6cae2b73d4c8d450d5408935015a4/_data",
"Destination": "/opt/graphite/conf",
"Driver": "local",
"Mode": "",
"RW": true,
"Propagation": ""
},
...
...
]
可見host的volume是：
"/var/lib/docker/volumes/5676877cb2df79ee28190c1be5f44eb7a4b6cae2b73d4c8d450d5408935015a4/_data"
對應到container中的volume是：
"/opt/graphite/conf"
此時如果嘗試進入host上對應的目錄會出錯,提示目錄不存在：
➜ ~ cd /var/lib/docker/volumes/5676877cb2df79ee28190c1be5f44eb7a4b6cae2b73d4c8d450d5408935015a4/_data
cd: no such file or directory: /var/lib/docker/volumes/5676877cb2df79ee28190c1be5f44eb7a4b6cae2b73d4c8d450d5408935015a4/_data
解決方法：
在Mac OS下，進入以下目錄
~/Library/Containers/com.docker.docker/Data/vms/0/
可以看到目錄下有一個tty設備，screen連接進去，host對應的volume可以在這個linux實例中找到,進入該目錄，其中的文件與container中的/opt/graphite/conf目錄下的內容一致：
➜ ~ cd ~/Library/Containers/com.docker.docker/Data/vms/0
➜ 0 ll
total 9853192
srwxr-xr-x 1 chenxi staff 0B Sep 20 14:25 00000002.000005f4
srwxr-xr-x 1 chenxi staff 0B Sep 20 14:25 00000002.00001000
srwxr-xr-x 1 chenxi staff 0B Sep 20 14:25 00000002.00001001
srwxr-xr-x 1 chenxi staff 0B Sep 20 14:25 00000003.000005f5
srwxr-xr-x 1 chenxi staff 0B Sep 20 14:25 00000003.00000948
-rw-r--r--@ 1 chenxi staff 60G Sep 20 15:29 Docker.raw
-rw-r--r-- 1 chenxi staff 92K Sep 20 14:25 config.iso
srwxr-xr-x 1 chenxi staff 0B Sep 20 14:25 connect
lrwxr-xr-x 1 chenxi staff 17B Sep 20 14:25 guest.000005f5 -> 00000003.000005f5
lrwxr-xr-x 1 chenxi staff 17B Sep 20 14:25 guest.00000948 -> 00000003.00000948
-rw-r--r-- 1 chenxi staff 2.2K Sep 20 14:25 hyperkit.json
-rw-r--r-- 1 chenxi staff 5B Sep 20 14:25 hyperkit.pid
drwxr-xr-x 2 chenxi staff 64B Aug 21 15:26 log
-rw-r--r-- 1 chenxi staff 36B Aug 21 15:26 nic1.uuid
lrwxr-xr-x 1 chenxi staff 12B Sep 20 14:25 tty -> /dev/ttys006
➜ 0 screen tty
####下面進入了linux實例####
linuxkit-025000000001:~#
linuxkit-025000000001:~#
linuxkit-025000000001:~# cd /var/lib/docker/volumes/5676877cb2df79ee28190c1be5f44eb7a4b6cae2b73d4c8d450d5408935015a4/_data
linuxkit-025000000001:/var/lib/docker/volumes/5676877cb2df79ee28190c1be5f44eb7a4b6cae2b73d4c8d450d5408935015a4/_data#ls -l
total 144
-rw-r--r-- 1 root root 1477 Sep 5 20:16 aggregation-rules.conf
-rw-r--r-- 1 root root 1798 Sep 16 19:04 aggregation-rules.conf.example
-rw-r--r-- 1 root root 274 Sep 5 20:16 blacklist.conf
-rw-r--r-- 1 root root 492 Sep 16 19:04 blacklist.conf.example
-rw-r--r-- 1 root root 2593 Sep 5 20:16 carbon.amqp.conf
-rw-r--r-- 1 root root 2596 Sep 16 19:04 carbon.amqp.conf.example
-rw-r--r-- 1 root root 27458 Sep 5 20:16 carbon.conf
-rw-r--r-- 1 root root 29876 Sep 16 19:04 carbon.conf.example
-rw-r--r-- 1 root root 1892 Sep 5 20:16 dashboard.conf
-rw-r--r-- 1 root root 1891 Sep 16 19:04 dashboard.conf.example
-rw-r--r-- 1 root root 729 Sep 5 20:16 graphTemplates.conf
-rw-r--r-- 1 root root 2445 Sep 16 19:04 graphTemplates.conf.example
-rwxr-xr-x 1 root root 90 Sep 16 19:04 graphite.wsgi.example
-rw-r--r-- 1 root root 873 Sep 5 20:16 relay-rules.conf
-rw-r--r-- 1 root root 888 Sep 16 19:04 relay-rules.conf.example
-rw-r--r-- 1 root root 558 Sep 5 20:16 rewrite-rules.conf
-rw-r--r-- 1 root root 558 Sep 16 19:04 rewrite-rules.conf.example
-rw-r--r-- 1 root root 988 Sep 5 20:16 storage-aggregation.conf
-rw-r--r-- 1 root root 827 Sep 16 19:04 storage-aggregation.conf.example
-rw-r--r-- 1 root root 881 Sep 5 20:16 storage-schemas.conf
-rw-r--r-- 1 root root 1040 Sep 16 19:04 storage-schemas.conf.example
-rw-r--r-- 1 root root 315 Sep 5 20:16 whitelist.conf
-rw-r--r-- 1 root root 315 Sep 16 19:04 whitelist.conf.example