Thank your for the quick reply.
I followed the documentation you suggested, but am not sure, if it is the correct way:
after installing suPHP and restarting the webserver says:
Starting web server: Apache2Syntax error on line 46 of /etc/apache2/vhosts/Vhosts_ispconfig.conf:
Invalid command 'php_admin_value', perhaps mis-spelled or defined by a module not included in the server configuration
All commands which contains "php" are marked as an error, i found following reason for it:
suphp doesn't support the php_flag, php_value, php_admin_value, and
php_admin_flag directives. Primarily because mod_php is no longer
loaded after suphp is installed. Use suPHP_ConfigPath in each vHost
and setup individual php.ini files.
As far as i know those directives are generated and used by ISPConfig, so do i really have to setup individual php.ini's for each vhost?