Multiple versions php - Some issues

Hi, I wanted to ask for advice about this situation: I need to host some websites that must use php 5.2 and I have founded an easy way to achieve that adding a PPA (ppa:skettler/php). With a clean install of Ubuntu 12.04 I have proceed to install first Virtualmin and then added the PPA and installed php52, after that I have php 5.3.10 and php 5.2.17 but I have some issues:
After installing php 5.2 from the PPA, in the terminal the command: php -v give me this:

PHP Warning: PHP Startup: Unable to load dynamic library ‘/usr/lib/php5/20090626/mysql.so’ - /usr/lib/php5/20090626/mysql.so: cannot open shared object file: No such file or directory in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library ‘/usr/lib/php5/20090626/mysqli.so’ - /usr/lib/php5/20090626/mysqli.so: cannot open shared object file: No such file or directory in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library ‘/usr/lib/php5/20090626/pdo_mysql.so’ - /usr/lib/php5/20090626/pdo_mysql.so: cannot open shared object file: No such file or directory in Unknown on line 0
PHP 5.3.10-1ubuntu3.15 with Suhosin-Patch (cli) (built: Oct 29 2014 12:19:04)
Copyright © 1997-2012 The PHP Group
Zend Engine v2.3.0, Copyright © 1998-2012 Zend Technologies

The only way to take away the PHP Warnings was marking as comment the lines about mysql.so, mysqli.so and pdo_mysql.so in /etc/php5/conf.d/mysql.ini, /etc/php5/conf.d/pdo.ini and /etc/php5/conf.d/pdo_mysql.ini

With that changes theres no PHP Warning but I don’t know if it could cause future issue.

After that I have restored a website that use PHP 5.2 but at the last step virtualmin gaves me an error:
Restore failed : Failed to write to /home/todoestabien/etc/php5/php.ini : Disk quota exceeded at …/web-lib-funcs.pl line 1397.

Could you help me to understand what this error means or how to solve it?

Even with that error I’m able to have the website working.

Thanks in advance.