Cakephp and memcached

I am trying to get memcached working with my cake installation.

I have a shared folder cakephp according to:

http://book.cakephp.org/2.0/en/installation/advanced-installation.html

      

        
        
        
      

    

My webroot / inidex.php has a line

define('CAKE_CORE_INCLUDE_PATH', DS . 'var' . DS . 'cakephp25' . DS . 'lib');

      

        
        
        
      

    

This way all my applications use / var / cakephp25 / as lib folder.

However, when I enable memcached with:

$engine = 'Memcached';

      

        
        
        
      

    

in core.php I get:

Fatal error:  Class 'Memcached' not found in /var/cakephp25/lib/Cake/Cache/Cache.php on line 179