Every time a PHP error occurs on your site – whether it’s just a warning or an actual error – it is written to an error_log file in the folder where the failing file is located.
This means that some error_log files can grow very large if a page keeps generating warnings and errors every time it loads. In the end, this can result in having error_log files on your web hosting account that in some cases can take up several hundred MB.
However, you can disable this error_log if you don’t use it, or simply limit it to only writing fatal errors to the file.
You do this by editing your php.ini file.
You can find it by logging into cPanel, and then going to "PHP INI Editor".
Under this menu item, you need to select "Editor" mode and then choose the site you want to edit the ini file for.
In your ini file you can now add:
log_errors = Off
This completely disables writing errors to error_log files.
error_reporting = E_ERROR
Only writes fatal errors (not warnings) to error_log files.