The session to files do not appear in sessions folder

Hello,

The session to files do not appear in ../sessions folder.
/sessions folder with cmod 0777
Any suggestion?

Using database that works.

$config['sess_driver'] = 'files';
//$config['sess_driver'] = 'database';
$config['sess_cookie_name'] = 'of';
$config['sess_expiration'] = 0;
$config['sess_save_path'] = FCPATH.'application/sessions';
//$config['sess_save_path'] = 'ci_sessions';
$config['sess_match_ip'] = FALSE;
$config['sess_time_to_update'] = 300;
$config['sess_regenerate_destroy'] = FALSE;

Thanks.