1. first, run `man startx` to see sample /root/.xinitrc file

2. create /root/.xinitrc file

  #!/bin/bash
  xrdb -load $HOME/.Xresources
  xsetroot -solid gray &
  xclock -g 50x50-0+0 -bw 0 &
  xload -g 50x50-50+0 -bw 0 &
  xterm -g 80x24+0+0 &
  xterm -g 80x24+0-0 &
  twm

3. generate new config file:

  startx -- :2 -configure

4. test config file:

  startx -- :2 -config /root/xorg.conf.new