Switching from run level 5 to 3 hangs

[Ben Stringer]

On Tue, 2004-01-13 at 22:46, Matt wrote:
> What exactly is the purpose of mingetty? It opens /dev/tty[1-6], and
> runs the (text) login program? In X (VT7), I ran `ps aux` and noticed
> that there were entries for `/sbin/mingetty tty[1-5]`. Why not tty6 as
> well? Also, out of curiosity, I tried to `kill -9` the tty5 mingetty
> process and switch to that VT, but the login prompt was still there. I
> thought it would have been terminated - maybe just a blank screen in
> place? On that note, what else is mingetty doing to keep running after
> being killed?

Have a look in /etc/inittab - the mingetty processes will be respawned
(by the init process) should they die for any reason.

You won't see a mingetty process if you have logged onto the VT
associated with that mingetty, as (presumably) it execs the login shell.

>  
> > Console input will only work on VT 1-6. You can of course change that
> > though by altering the 'inittab' but be careful, and the X  device
> > moves from 7 to 8 and so on if you do it.
> > 
> > Matt, are you still seeing a 'hang' when using virtual terminal 1-6 ?
> 
> What exactly are you meaning by "console input"? A tty line outside of a
> X shell environment? And yes, as per above, this problem is solved by
> switching to VT1-6 and running the aforementioned command. But I do
> wonder if this really is a feature..Many docs that mention exiting the X
> server to runlevel 3 never specify the need to switch to a VT first.
> 
> What are the key differences between a VT session and switching to run
> level 3? I noticed that in a VT, all the processes associated with VT7
> were still running within that VT. OTOH, as expected, running in
> runlevel 3 contains no X related processes such as gdm and
> gnome-session.  

Switching to runlevel 3 will cause init to attempt to stop all services
started in runlevel 5. It will do this by attempting to execute all the
/etc/rc5.d/K* scripts. By default, the X display manager is started at
runlevel 5, so runlevel 3 gets rid of X.

VTs are just terminals you can log into. They are not affected by the
runlevel.

Cheers, Ben
-- 
.O.    Ben Stringer
..O    ben at burbong.com
OOO    linux|java|majitek|gnu