问一个PHP的问题

hf_linux

我把SERVER的APACHE 重新启动了。在访问我的页面就成了:

不知道怎么恢复啊(不要说要REBOOT)
Warning: open(/tmp/sess_c4177e0c3d3bbb7a4f72e2f4fa33d19d, O_RDWR) failed: No such file or directory (2) in /htdocs/user/login.php on line 3
..........
Warning: open(/tmp/sess_c4177e0c3d3bbb7a4f72e2f4fa33d19d, O_RDWR) failed: No such file or directory (2) in Unknown on line 0

Warning: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0