https://blog.wongcw.com/2018/09/29/%e5%9f%ba%e4%ba%8e-centos-%e6%90%ad%e5%bb%ba-vnc-%e8%bf%9c%e7%a8%8b%e6%a1%8c%e9%9d%a2%e6%9c%8d%e5%8a%a1/