Fatal error: Uncaught exception 'Zend_Session_Exception' with message ' in /usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Session.php on line 482

Zend_Session_Exception: Zend_Session::start() - /usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Session.php(Line:469): Error #2 session_start(): open(/var/lib/php5/sess_fe041dcn6h67e4oa7tbirfvs06, O_RDWR) failed: Input/output error (5) Array
/usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Session.php(Line:479): Error #2 session_write_close(): open(/var/lib/php5/sess_fe041dcn6h67e4oa7tbirfvs06, O_RDWR) failed: Input/output error (5) Array
/usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Session.php(Line:479): Error #2 session_write_close(): Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/var/lib/php5) Array in /usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Session.php on line 482

Call Stack:
    0.0038     333196   1. {main}() /usr/local/share/webapp/nsra/public/index.php:0
    0.1009    1144400   2. Zend_Application->bootstrap() /usr/local/share/webapp/nsra/public/index.php:25
    0.1009    1144444   3. Zend_Application_Bootstrap_BootstrapAbstract->bootstrap() /usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Application.php:355
    0.1009    1144444   4. Zend_Application_Bootstrap_BootstrapAbstract->_bootstrap() /usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Application/Bootstrap/BootstrapAbstract.php:586
    0.1323    1953052   5. Zend_Application_Bootstrap_BootstrapAbstract->_executeResource() /usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Application/Bootstrap/BootstrapAbstract.php:622
    0.1325    1953236   6. Bootstrap->_initView() /usr/local/share/zend/ZendFramework-1.11.11/library/Zend/Application/Bootstrap/BootstrapAbstract.php:669
    0.1837    2503492   7. Zend_Session::start() /usr/local/share/webapp/nsra/application/Bootstrap.php:17