Comment 7 for bug 967229

1. As logout, the X Server exit and lightdm respawn another instance of X Server. So content of text console appear for that short interval. If we don't clean the text in console, then we need to re-design the behavior as logout (which I have no idea how)

2. The text that is left on the Text console comes from other process that upstart bring up. In my observation, upstart starts program in parallel in possible. As it run lightdm, it switch to tty7 and other process that start up after output their message to tty7.

I try to delay lightdm startup time (add sleep 5 before exec lightdm), then the tty7 is clean. So as logout / reboot / shutdown, no such text message is displayed. Only black screen is displayed.

I think the correct solution is: make upstart output program startup message to tty1, only span '/sbin/getty -8 38400 tty1' only after all other program starts on boot.