Solved - Codeigniter Message: mkdir(): Invalid path and Sess

Bertemu lagi dengan masalah dan revisi tiada akhir :p memang sudah menjadi rezeki nya,,
kesulitan dan kesusahan juga rezeki loh kalau kita mau mengambil sisi positifnya
Masalah yang saya temui di Codeigniter 3.0, namun masalah ini tidak hanya di versi 3.x saja mungkin di versi sebelumnya juga ada.

Konsidi masalah :
Webserver : Nginx & apache
Php : PHP 5.6
FrameWork : Codeigniter 3.

masalah yang muncul ada 3 tapi cara mengatasinya hanya dalam 1 baris code, sebelumnya lihat kode errornya ada dibawah ini :
============================================================================================================

A PHP Error was encountered
Severity: Warning
Message: mkdir(): Invalid path
Filename: drivers/Session_files_driver.php
Line Number: 117
Backtrace:
File: /usr/share/nginx/html/ci/index.php
Line: 292
Function: require_once

============================================================================================================

An uncaught Exception was encountered
Type: Exception
Message: Session: Configured save path '' is not a directory, doesn't exist or cannot be created.
Filename: /usr/share/nginx/html/ci/system/libraries/Session/drivers/Session_files_driver.php
Line Number: 119
Backtrace:
File: /usr/share/nginx/html/ci/index.php
Line: 292
Function: require_once

============================================================================================================
A PHP Error was encountered
Severity: Warning
Message: fopen(ea936f6cca00382143f867cea8043f45d9b818c2): failed to open stream: Permission denied
Filename: drivers/Session_files_driver.php
Line Number: 156
Backtrace:

============================================================================================================

Cara mengatasinya :
1. Buka file config.php dalam direktori Codeigniter
2. Temukan kode berikut :

$config['sess_save_path'] = NULL;

3. Ganti menjadi :

$config['sess_save_path'] = sys_get_temp_dir();