Php - Your PHP installation appears to be missing the MySQL extension which is required by WordPress
in the end i found a solution First, make sure MySQL server is running. Type the following command at a shell prompt:
/etc/init.d/mysql status
If MySQL is not running, enter:
/etc/init.d/mysql start
If MySQL is not installed, type the following command to install MySQL server:
apt-get install mysql-server
Make sure MySQL module for php5 is installed:
dpkg --list | grep php5-mysql
To install php5-mysql module enter:
apt-get install php5-mysql
Next, restart the Apache2 web server:
/etc/init.d/apache2 restart
The php mysql api is deprecated. It's kaput --- going away -- not to be used, finito.
If you have a modern version of PHP (> 5.6) then Wordpress should automatically switch to make use of mysqli. That should be your first attempt.
If you can not update your php, rather than attempting to resurrect something that php no longer supports, just patch your wordpress: http://wordpress.org/plugins/mysqli/