This answer explains how you can change the global PHP settings on your VPS server.
Please note: this article was originally created for our previous generation of Virtual Private Servers. As such, these instructions may not be relevant to our current generation of Virtual Private Servers.
Depending on whether you want to edit the PHP values for the Apache or CGI version, please edit 1 of the following file paths below:
Apache file path
/etc/php5/apache2/php.ini
CGI file path
/etc/php5/cgi/php.ini
For example: to turn register_globals on you will need to change the line;
register_globals = Off
to
register_globals = On
This will turn register_globals on for every domain on the VPS unless a domain has a different value specified in its vhost.conf file.