اینو توی همون فایل config زده بخون
'sess_save_path'
The location to save sessions to, driver dependent.
For the 'files' driver, it's a path to a writable directory.
WARNING: Only absolute paths are supported!
For the 'database' driver, it's a table name.
Please read up the manual for the format with other session drivers.
IMPORTANT: You are REQUIRED to set a valid save path!
$config['sess_driver'] = 'files';$config['sess_cookie_name'] = 'ci_session';$config['sess_expiration'] = 86400;$config['sess_save_path'] = './../sessStore/';$config['sess_match_ip'] = FALSE;$config['sess_time_to_update'] = 3600;$config['sess_regenerate_destroy'] = TRUE;
من خودم یه چیز شبیه این میزنم
$config['cookie_prefix'] = '';$config['cookie_domain'] = '';$config['cookie_path'] = '/';$config['cookie_secure'] = FALSE;$config['cookie_httponly'] = FALSE;
$config['csrf_protection'] = TRUE;$config['csrf_token_name'] = 'csrf_test_name';$config['csrf_cookie_name'] = 'csrf_cookie_name';