Switching from run level 5 to 3 hangs

[Matt]

On Tue, 2004-01-13 at 19:21, Igor Antonacci wrote:

> Hi,
> I've the same problem...when I switch to runlevel 3
> it hangs.
> A workaround is switching into another console 
> (Ctrl-Alt-F1...F4) leaving the console no. 7 .
> 
> What kernel do you have ? The one I have is
> 2.4.22.2115. 
Yes, it seems that being in a VT is necessary to successfully run the `init 3` command. 
This indeed worked. BTW, this must not be a bug since I use the latest 2.4.22.2140.nptl 
and this behaviour is still resident.

On Tue, 2004-01-13 at 19:27, Naoki wrote: 
> Wait a sec. This doesn't sound like a bug anymore, sounds like a
> feature :)
> There are only six virtual terminals enabled by default (1-6 funnily
> enough) now if you issue the "/sbin/init 3" command from inside an X
> window then it will drop down to the terminal from which it started
> (7) but of course there is no 'mingetty' spawned for that device and
> you can't do anything. You need to switch to one of the others.

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?
 
> 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.  

On Tue, 2004-01-13 at 19:29, jurgen.defurne at philips.com wrote: 
> Hi, Guys,
> 
> Are you switiching in a terminal, and getting like 
> 
> message                   [OK]
> message                   [OK[
> 
> and the system does not show the prompt at the
> terminal anymore ?
> 
> This is no hang, it is just that the background process
> writes to the console, but the current shell
> does not know about it, thus the prompt gets clobbered
> by the init messages.
> 
> Just press enter to redisplay the prompt.
> 
> Regards,
> 
> Jurgen

Yes, pressing enter when this happens when initiated in a VT will bring the prompt back, 
however this does not work when trying to switch from the X shell (VT7).

On Tue, 2004-01-13 at 19:53, David Balazic wrote: 

> What exactly is the right behavior in you opinion ?
> In runlevel 3 there is nothing running on VT7 (except some system messages
> sometimes appear),

Well IMHO, this process should be more intuitive. Although *once* you know that 
switching VT's before switching runlevels is needed, this can lead to one seeing
it as a "bug".
 
you MUST switch to VT1 ( or any VT between 1 and 6 ) and work there. That is
> what runlevel 3 means.

As I queried above, it's my understanding that a VT and running in level 3 are 
not synonymous?

-- 
Matt