1.

systemctl set-default multi-user.target

reboot



2.

export VIRTUAL_GL=2.6.1

wget https://sourceforge.net/projects/virtualgl/files/${VIRTUAL_GL}/virtualgl_${VIRTUAL_GL}_amd64.deb/download -O virtualgl_${VIRTUAL_GL}_amd64.deb

sudo dpkg -i virtualgl*.deb



3.

sudo /opt/VirtualGL/bin/vglserver_config -config +s +f -t



reboot



4. 

https://unix.stackexchange.com/questions/209746/how-to-resolve-no-protocol-specified-for-su-user 참고


ps aux | grep Xorg


sudo xauth -f '/var/run/sddm/{13a5b313-99dc-4792-b1c9-5a43b497345d}' list

xauth add $DISPLAY MIT-MAGIC-COOKIE-1 23ef877f02a4242088eea5927719f84c