Serial console connection problem

[Jani Luukkanen]

Jonathan Chen wrote:

>On Fri, Apr 08, 2005 at 09:49:49AM +0300, Jani Luukkanen wrote:
>
>[...]
>  
>
>>Weird, fstat shows nothing on the port;
>>
>>root at mos root # fstat /dev/cuaa0
>>USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W NAME
>>root at mos root #
>>
>>And yes, this is problem is on the 4.10 machine which is connecting to 
>>the 5.3 one.
>>
>>    
>>
>[...]
>  
>
>>Might be this is the problem, here is all gettys running on the 4.10 
>>machine:
>>    
>>
>
>[...]
>  
>
>>root     238  0.0  0.1   956  516  d0  Is   16Mar05   0:00.00 
>>/usr/libexec/getty std.9600 console
>>
>>The last one (console) does not appear on the 5.3 machines processlist, 
>>would it be safe to kill that one just like that with kill -9 238 (If 
>>that is the process locking the port)?
>>    
>>
Ok, I presume would have to disable the "Serial terminals" section with 
entries such as;
ttyd0   "/usr/libexec/getty std.9600"   ansi    off secure ?

The fact that the 5.3 box bios has the built-in serial terminal feature 
enabled doesnt affect to this one?
In sense that it should enable the possibility to even make bios changes 
or install OS wherever text mode is available. (Main idea of the thing 
is to ensure availability of the other machine)

>You have to do a bit more than this. First you have to disable the
>getty on the 4.10 machine by editing /etc/ttys, and then "kill -HUP 1"
>and then kill the getty if it still exists.
>
>You then have to enable the getty on the the 5.3 box by editing
>/etc/ttys and then "kill -HUP 1".
>
>The getty has to be running on the machine that you're going to
>connect *to*.
>
>  
>
>>The connection is ordinary serial cable, do you mean that should specify 
>>from BSD side what kind of connection is it?
>>
>>    
>>
>>>Make sure that you haven't got a getty running at the same time on
>>>both sides, and that you've got a null-modem connection between the two
>>>hosts instead of a straight thru'.
>>>
>>>      
>>>
>
>  
>
Hmm, before upgrading to 5.3 the connection worked with the same cable 
(though tested only with minicom which also now says Device busy), so I 
still suspect it might be still some OS-side thing.

>Serial cables come in 2 basic flavours: straight thru' and null-modem.
>A straight-thru is what you use if you want to connect the machine to
>a modem. A null-modem connection is what you use if you want to
>connect from host to host. If you use the wrong cable, no output will
>show, and you may possibly get a device-busy message as well.
>
>Cheers.
>  
>
Thanks again,

Jani