On Windows (10), DOCKER appears to be running on Hyper-V. like VM mount.
So, architecture docker server is on running VM BOX. The default volume mount setting is c / Users. You can add this in the Oracle VM VertualBox> setting> shared folder. Or C:\Users[realuser].docker\machine\machines\default\default\default.vbox.
<SharedFolders>
<SharedFolder name="c/Users" hostPath="\\?\c:\Users" writable="true" autoMount="true"/>
<SharedFolder name="f/dockerVolume" hostPath="\\?\f:\dockerVolume" writable="true" autoMount="true"/> <!--this is addition-->
</SharedFolders>
You can add docker container expose volume mount to VM mount. if you change vm mount, restart ‘defult’ VM in the Oracle VM VirtualBox or Restart
Windows (mount_here)<----> Virtual Box (mount_here)<—> CoreOS(mount_here)
And I found this, if use Kitematic, only can use Users folder.