I decided to install the PHP APC module on my server in order to speed things up a little bit. Installing the data was no big problem (running Ubuntu with apache2, php5) but for some reason I'm having some trouble activating it.
After running the command 'pecl install apc', I received several status information from the system according to which everything worked fine, ending with the lines:
Build process completed successfully
install ok: channel://pecl.php.net/APC-3.0.18
configuration option "php_ini" is not set to php.ini location
You should add "extension=apc.so" to php.ini
Now as soon as I add the line extension=apc.so to my php.ini file and restart apache, my website remains blank: no error messages or anything, just a white page. If I remove the line again, everything goes back to normal.
In other tutorials I have read that the commands to enable and configure apc belong into another file called apc.ini. Also, if I run a phpinfo script on my server, under the section "additional ini files parsed", it shows the entry /etc/php5/apache2/conf.d/apc.ini. However, if I look up this file under the given path and add the extension=apc.so line there, the same error occurs.
I do not know if there is another way to verify whether the installation of the apc module went without problems but the file "apc.so" exists in my folder structure so I assume that so far everything worked fine.