Hi , i've installed the multi sites extension, but i don't understand the english documention ...
i've 4 web site :

blog.overgame.com
blog2.overgame.com
blog3.overgame.com
blog4.overgame.com

but i've installed the extension in blog.overgame.com , now i want to add the 3 others websites ... but when i've add the second site ( blog2.overgame.com) , nothing happen ... ( i 've think , there was an installation of joomla!)

So what should i do to add a new site ? Change the httpd.conf ?

Thanks

I suggest that you first try follow the tutorial video CP-04 that show you things step by step and you would see also the expected result at each step.

As you mentioned to update the "httpd.conf", I suppose that you are not using cPanel but directly updating the native apache code.
I suggest that you have a look in the user manual chapter 3.2.4 that give some sample of <VirtualHost> section.
The httpd.conf "document root" and the JMS deploy folder must have the same value.

To check your httpd.conf configuration, you can also put the "hello.php" file in the document root directory to verify the apache setup.
When you are able to execute the "hello.php" file then you can try defining the JMS slave site.