ubuntu lxde slim не стартует x11vnc

выдавал ошибку: auth guess: failed for display='unset' x11vnc

для slim параметры запуска x11vnc:

# nano /lib/systemd/system/x11vnc.service
[Unit]
Description=Start x11vnc at startup.
After=multi-user.target

[Service]
Type=simple
ExecStart=/usr/bin/x11vnc -auth guess -forever -loop -noxdamage -display :0 -auth /var/run/slim.auth -repeat -rfbauth /home/user/.vnc/passwd -rfbport 5900 -shared

[Install]
WantedBy=multi-user.target

# systemctl daemon-reload

# systemctl enable x11vnc.service

# reboot

vnc работает!