systemctl set-default graphical.target #graphical.target相当于level5,multi-user.target相当于level3
yum install tigervnc-server
cp /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:1.service
cp /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:1.service