做开发的时候，操作session有时候会遇到这个问题：Warning: session_start() [function.session-start]……
PHP环境：
OS:CentOS release 5.2 (Final)
Apache:
Server version: Apache/2.2.3
Server built: Jan 15 2008 20:33:30
php:
PHP 5.1.6 (cli) (built: May 24 2008 14:07:53)
Copyright (c) 1997-2006 The PHP Group
Zend Engine v2.1.0, Copyright (c) 1998-2006 Zend Technologies
报错信息如下：
代码如下:
Warning:session_start()[function.session-start]:open(/var/lib/php/session/sess_itqfqua1554rmkgcb8u89ujem5,O_RDWR)failed:Permission denied(13)in www_path on line 9
Warning:Unknown:open(/var/lib/php/session/sess_itqfqua1554rmkgcb8u89ujem5,O_RDWR)failed:Permission denied(13)in Unknown on line 0
Warning:Unknown:Failed to write session data (files);Please verify that the current setting of session.sav_path is correct (/var/lib/php/session)in Unknown on line 0
解决办法：
方法1、注释掉/etc/php.ini中
session.save_path = “/var/lib/php/session”
方法2、查看apache用户和组，然后将该用户加到session文件夹所处的组中。
方法3,在session_start() 前不要有任何输出！
然后重启Apache;
OK,问题解决！