Here are the basic steps to install another wordpress weblog on a multiple web sites infrastructure over a single apache2 on debian.

1. Create the new database

In order to pick a consistent database name, check the existing databases and create a new one. Then create a new username and give it full access.

mysql> SHOW DATABASES;
mysql> CREATE DATABASE <databasename>;
mysql> SELECT User, Password, Host from user;
mysql> GRANT ALL PRIVILEGES ON <databasename>.* TO <username>@<hostname> INDENTIFIED BY <password>;
mysql> FLUSH PRIVILEGES;
mysql> EXIT;

2. Setup the wp-config file

2.1 Copy wp-config.php to config-<website>.php

2.2 Update config-website.php constants with the info from above

define('DB\_NAME', '<databasename>'); // The name of the database
define('DB\_USER', '<username>'); // Your MySQL username
define('DB\_PASSWORD', '<password>'); // ...and password
define('DB\_HOST', '<hostname>'); // 99% chance you won't need to change this value

3. Setup Apache2 web site

3.1 Create a website path

ln -s /usr/share/wordpress /var/www/<website>

3.2 Create logs folder

mkdir /var/log/apache2/<website>

3.3 Create a new apache configuration file for the website

/etc/apache2/sites-available/<website>

<VirtualHost *:80>
        ServerName <website>
        ServerAdmin webmaster@<domain>

        DocumentRoot /var/www/<website>/
        <Directory /var/www/<website>>
                Options ...

                # hack for nice URIs
                <IfModule mod_rewrite.c>
                        RewriteEngine On
                        RewriteBase /
                        RewriteCond %{REQUEST_FILENAME} !-f
                        RewriteCond %{REQUEST_FILENAME} !-d
                        RewriteRule . /index.php [L]
                </IfModule>

        </Directory>
        ...
        LogLevel warn
        ErrorLog /var/log/apache2/<website>/error.log
        CustomLog /var/log/apache2/<website>/access.log combined
        ...
</VirtualHost>

3.4 Enable the new website

a2ensite website

3.5 Reload Apache2 configuration

/etc/init.d/apache2 reload

3.6 Run the install script: https://<website>/wp-admin/install.php

And Voila, you have a new weblog.

References