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In searching for a way to see the messages on my machine's console (the tty I get when hitting Ctrl+Alt+F7) from a shell, it was suggested to me that /dev/vcs7 was the appropriate place to look. This seems to work for tty's 1-6 - I can cat /dev/vcs1 and see the login prompt for the unused tty's. However, my system has no /dev/vcs7. There are /dev/vcs and /dev/vcsa for numbers 1-8, plus an unnumbered vcs(a), but no vcs(a)7.

Is this by design? If not, how can I fix it?

I'm running Linux Mint 17.2, btw.

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  • It doesn't look by design, my 17.2 has it and I can change to it. Do you start your X session by hand? Have you checked after a reboot? Tried starting 17.2 from CD/USB? Maybe some installed software you run has killed that off.
    – Anthon
    Aug 23 '15 at 5:05
  • The primary X session starts automagically, and I've got the machine set to auto-login as my user (the system seems to disable audio if the physical machine isn't logged in to an X session, and this system is a media server I use to play music). I control the system through a second session, via vnc. Running "who -a" shows the X session using tty8 & pts/8, and the vnc X session on pts/4, tty 1-8 unused, and no listing at all for tty7.
    – meeotch
    Aug 23 '15 at 17:41
  • I should add that I can't start the X session manually, because the system runs headless in a closet. If the power goes out when I'm not home, for instance, I want it to recover on its own.
    – meeotch
    Aug 23 '15 at 17:48
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Linux VT console devices are dynamically allocated. They appear when they are opened by any process, just echo >/dev/tty63 will do that. You might be interested in utilities like openvt / deallocvt / chvt.

Missing /dev/vcs7 is probably because Xorg session is using /dev/tty7 in graphics mode. Xorg uses the first unused console device found beginning from /dev/tty1. In /var/log/Xorg.0.log you would find the following line:

[     6.446] (++) using VT number 7

And you could see the mode of /dev/tty7 by kbdinfo:

# kbdinfo -C /dev/tty7 getmode
graphics

If you shut down the Xorg session (by sudo stop mdm or something like that, I have no experience with Mint), /dev/tty7 would become free to use.

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  • Correct assumption. @user6081: That is why [Ctrl][Alt][F1-6] gets you a text terminal, but [Ctrl][Alt][F7] brings you the Mint GUI.
    – Fabby
    Aug 23 '15 at 8:41
  • On my machine (I believe this is the Mint default, and possibly Ubuntu, from which Mint is derived) the X session uses tty8. Grepping Xorg.0.log and using kbdinfo as you described confirms this. ctrl-alt-F8 gets me the Mint GUI, and ctrl-alt-F7 gets me a text console with a few startup messages still sitting in it. kbdinfo on tty7 returns mode "text".
    – meeotch
    Aug 23 '15 at 17:32
  • @user6081 On Ubuntu, X runs on tty7 by default. Aug 23 '15 at 19:39
  • Interesting. So how do you get to the (text) startup console? Or is tty7 essentially usurped as soon as X starts, and then there's no way back to the startup console?
    – meeotch
    Aug 23 '15 at 23:15

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