systemctl list-unit-files --type service --all
操作防火墙：
https://www.jianshu.com/p/411274f96492
操作VNC；
从realVNC官网下载RPM包
安装后添加key:
vnclicense -add XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
vncserver-virtuald.service disabled
vncserver-x11-serviced.service disabled
systemctl enable vncserver-virtuald.service
systemctl enable vncserver-x11-serviced.service