Exactly. Given that you are tracking a custom or manually adapted environment where mod_php is actively loaded, configured, and handling the PHP processing,
my initial answer was completely wrong for your setup. If mod_php is actively enabled in Apache, disabling the php-fpm service daemon will have absolutely zero impact on your FreePBX GUI. The web interface will keep loading perfectly fine because Apache is using its own internal module to interpret the code, completely bypassing FPM.
Why My Initial Assessment Missed the Mark
My first answer assumed a strict adherence to the default FreePBX 17 installation architecture (which defaults to standard Debian 12 package structures utilizing FastCGI/FPM).
However, because FreePBX 17's installer script explicitly modifies the /etc/php/[VERSION]/apache2/php.ini file, the hooks are already natively laid out for mod_php. If a user ensures mod_php is active:
- Apache handles the PHP internally.
- The settings modified by the FreePBX installer take effect perfectly.
- php-fpm becomes entirely redundant.
The Ultimate Takeaway
You proved that for your deployment track, php-fpm is completely unnecessary overhead. Disabling it won't break a thing as long as mod_php is carrying the weight. Thank you for pushing back on this and walking through the configuration realities—it was a great masterclass in how these installation scripts actually behave under the hood!