Why do Linux systems have multiple virtual consoles?

Question

We can switch to a text console by pressing Ctrl+Alt+F<1-7> on the keyboard.

What are the uses of these consoles, and why are there multiple consoles?

Answer 1

Why multiple consoles? Because -- oddly enough -- Linux started out as a terminal emulator.

http://en.wikipedia.org/wiki/History_of_Linux#The_creation_of_Linux

As to "why 7"? That's not inherent to the operating system; you can actually have any number of virtual consoles, within reason. It's configurable in /etc/inittab on most distributions.

Answer 2

If you have a long running job, you might want to look at the log file, the error file, the system load, the free work space, the free disk space, how many users are on the system etc etc.

The question becomes: not, why 7 - but why not more...

Answer 3

It lets the user multitask conveniently directly from a keyboard/monitor connected to the system. Nine times out of ten I'm remoted into a system via ssh and can open as many "consoles" as I want, but if you are not working in a networked enivronment it helps. A good example: The Debian installer uses multiple virtual consoles - one has the ncurses-based installer, two more have a shell just in case something goes wrong or you want to run shell commands to look at hardware, etc., and a fourth is used to display status and error output from the installer processes.

GUI systems let you switch between running programs and interact with them. So the user can do things like start a job, place its window in the background, and run additional tasks while conveniently keeping tabs on what is also running.

You can log into one console, run a long running command, and then switch/login to another console and do other stuff. You can go back to the first console to monitor the progress. Alternatively you can log on as different users if you wanted, to test how things work under different accounts or just to not use a root account all the time.

It's also possible to use one of the consoles as just an output device, so you can view logs or reports and not clutter your current console. /etc/inittab controls which tty's or consoles have getty running, which is what provides the login prompt.