With your own dedicated server, many of the configuration tasks fall squarely on your shoulders. PHP is no exception. Most of the PHP configuration settings are found in the php.ini file, which is often located in /etc/php.ini on Linux servers. You must edit the file as root, and any configuration changes will only take effect after you restart your web server.
For example, a common setting that system administrators might want to change is the memory limit, which is generally too low for many web applications. Edit php.ini and find:
memory_limit = 16M
You can then change it to something like:
memory_limit = 64M
Save the file and then restart Apache:
service httpd restart
To see if changes have come into effect and to look at any other configuration settings you might want to change, you can create a phpinfo.php file in a regular document root of one your websites. Edit the file and add the following code:
Save it and then load that file from your web browser. It will print out a list of all PHP configuration settings.