[lxc-devel] lxc git branch

[Daniel Lezcano]

Dietmar Maurer wrote:
>>>> bring checkpoint/restart on top of lxc. And making the 'exec'
>>>> configurable is a way to organize the code and do some cleanup.
>>>>         
>>> Yes, but the current tty code make c/r impossible, because it uses
>>>       
>> pty
>>     
>>> resources of the host?
>>>       
>> Yes, you are right they won't be checkpointed but they should be
>> restored by the configuration when restarting (losing the buffer
>> content).
>>
>> Before changing this code, I have to finish the CR on top of lxc which
>> will take some months. I have been thinking about this point since
>>     
> Oren
>   
>> pointed it and I think it would be possible to invert the tty creation
>> into the container and pass the fd to the parent.
>>     
>
> Can we make that tty code optional? Or is this already possible?
>
> I just want to start the container without any tty proxy.
>
>   
>>> Btw, the current 'lxc-start' is an additinal process, staying around
>>>       
>> for
>>     
>>> the whole
>>> lifetime of a container. Don't you think we can remove that
>>>       
> overhead?
>   
>>> OpenVZ shows
>>> that it is not strictly needed.
>>>       
>> Yes, there is a supervision process on top of the first virtualized
>> process. It is in charge of monitoring the container, cleanup the
>> resources and wait for the child process for the exit status of the
>> application. The HPC guys agreed on this process because it can not be
>> avoided due to the pid namespace design.
>>
>> The legitimate question is "shall the lxc_start function do so much
>> things ?". No sure, maybe lxc_start just needs to fork/setup/exec and
>> returns the pid of the first process of the container and let the
>> caller
>> to handle that. But this is another story....
>>     
>
> I am just unhappy with the tty proxy - maybe you can move that out or
> make it optional?
>
>   
Yes it is already optional, just remove the line in the configuration file:

lxc.tty = 4 or if your container is already created remove the 'tty' 
file in the configuration tree.
If you don't want tty at all, comment in the inittab of the debian 
rootfs, the getty lines to avoid the annoying message 'bla bla respawn 
too fast etc...'

 -- Daniel