Home / ubuntu / Questions / 24497
Accepted
david25
Asked: 2011-02-03 09:08:06 +0800 CST

What do each of the TTYs do?

  • 772

I know that Alt+Ctrl+F1-F6 take me to available command lines, and that F1 command line is used for debugging, and F8 is the GUI desktop, that what i know but today i noticed there in F7 that does nothing, it only displays some sort of log in message, and there is F9-F12 that just display black screen with blinking under scroll .

can anyone enlighten me what those consoles do, are they for trouble shooting maybe? i use ubuntu netbook 10.10.

10.10

3 Answers

  1. Best Answer

    Ctrl+Alt+F1-F12 switches to different virtual terminals on your computer. What is running on terminal 1-6 is getty, which allows users to login to a CLI. Terminal 7 is probably running something like tail -f /var/log/messages (it doesn't do that on my machine).

    The configurations for these programs exists in /etc/init/tty[n].conf on ubuntu. You can put any command here, but remember that they will run as the root user. The virtual terminals after 6 (or 7 in your case) are free so that the X server will be able to bind to one, otherwise the program running in the background of the virtual terminal would be able to interfere with your graphical session.

    The reason for having these different virtual terminals is not actually debugging, but it is a historical relic from the time of timesharing systems, where several users would use the same mainframe from different terminals.

    http://www.linusakesson.net/programming/tty/index.php

    • 9

  2. In former times the consoles where controlled in a file called /etc/inittab. Since upstart and the like I'm not so sure where to find those configurations, but you should know that it is purely made by configuration how many active consoles you have, and on which of them what is displayed.

    There have been some conventions about them. I know of tty{1..6} for normal usage (login, getty), tty7 for X11, tty8 or 10 for loginfos. While pure textterms are getting rare on the desktop, tty7 often went to tty5.

    • 1

  3. F1-F6 are virtual consoles, for multitasking, with six enabled by default. To change this:

    sudo dpkg-reconfigure console-setup

    F7 is the Xserver console. As for F9-12, it is possible to configure the computer in such a way that these might be connected to real console devices through a serial port.

    • 1