Virtual consoles, put simply, enable you to have several simultaneous sessions on the same machine without doing anything complicated like setting up a network or running X.
When the system starts, it will display a login prompt on the monitor after displaying all the boot messages. You can then type in your login name and password and start working (or playing!) on the first virtual console.
At some point, you will probably wish to start another session, perhaps to look at documentation for a program you are running or to read your mail while waiting for an FTP transfer to finish. Just do Alt-F2 (hold down the Alt key and press the F2 key), and you will find a login prompt waiting for you on the second ``virtual console''! When you want to go back to the original session, do Alt-F1.
The default FreeBSD installation has three virtual consoles enabled, and Alt-F1, Alt-F2, and Alt-F3 will switch between these virtual consoles.
To enable more of them, edit /etc/ttys
and add entries for ``ttyv4'' to ``ttyvc'' after the
comment on ``Virtual terminals'':
# Edit the existing entry for ttyv3 in /etc/ttys and change
# "off" to "on".
ttyv3 "/usr/libexec/getty Pc" cons25 on secure
ttyv4 "/usr/libexec/getty Pc" cons25 on secure
ttyv5 "/usr/libexec/getty Pc" cons25 on secure
ttyv6 "/usr/libexec/getty Pc" cons25 on secure
ttyv7 "/usr/libexec/getty Pc" cons25 on secure
ttyv8 "/usr/libexec/getty Pc" cons25 on secure
ttyv9 "/usr/libexec/getty Pc" cons25 on secure
ttyva "/usr/libexec/getty Pc" cons25 on secure
ttyvb "/usr/libexec/getty Pc" cons25 on secure
Use as many or as few as you want. The more virtual terminals
you have, the more resources that are used; this can be important
if you have 8MB RAM or less. You may also want to change the
``secure'' to ``insecure''.
IMPORTANT NOTE if you want to run an X server you MUST leave at least one virtual terminal unused (or turned off) for it to use. That is to say that if you want to have a login prompt pop up for all twelve of your Alt-function keys, you're out of luck - you can only do this for eleven of them if you also want to run an X server on the same machine.
The easiest way to disable a console is by turning it off. For example, if you had the full 12 terminal allocation mentioned above and you wanted to run X, you would change settings for virtual terminal 12 from:
ttyvb "/usr/libexec/getty Pc" cons25 on secure
to:
ttyvb "/usr/libexec/getty Pc" cons25 off secure
If your keyboard has only ten function keys, you would end up with:
ttyv9 "/usr/libexec/getty Pc" cons25 off secure
ttyva "/usr/libexec/getty Pc" cons25 off secure
ttyvb "/usr/libexec/getty Pc" cons25 off secure
(You could also just delete these lines.)
Once you have edited /etc/ttys, the next step is to make sure that you have enough virtual terminal devices. The easiest way to do this is:
# cd /dev
# ./MAKEDEV vty12 # For 12 devices
Next, the easiest (and cleanest) way to activate the virtual
consoles is to reboot. However, if you really don't want to
reboot, you can just shut down the X Window system and execute (as
root):
kill -HUP 1
It's imperative that you completely shut down X Window if it is running, before running this command. If you don't, your system will probably appear to hang/lock up after executing the kill command.