If you have domain with CGI/FastCGI mode of PHP some of values will be taken from /var/www/vhosts/DOMAINNAME/conf/php.ini file despite of settings defined in Plesk interface. Thus priority of receiving settings for custom php.ini is following:
server-wide php.ini < PHP setting defined for the domain in the Plesk GUI < domain's conf/php.ini
You can find more details in chapter Applying Custom PHP Settings on Domains with PHP in CGI/FastCGI Mode of Advanced Administration Guide for Linux
Since the release of version 10.3, Parallels Plesk Panel for Unix allows one to enable the per-vhost php.ini configuration file when PHP runs in CGI or FastCGI mode.
The file is loaded from the following virtual host etc directory (for 10.3 - 11.0):
or (for 11.5) at:
And please note that applying these changes for 11.5 will require SSH root access - it will not possible to perform this via File Manager.
To enable virtual host-specific PHP configuration, open the Control Panel of the client to whom the domain belongs:
Go to the "Websites & Domains" tab, select the domain, enter its Hosting Settings, and switch PHP mode to FastCGI or CGI: