Codeigniter with Nginx - Not working

Hi

I am trying from yesterday. I am not able to run codeigniter with nginx. It is working well in localhost on windows.
Right now i am seeing the blank page, But the error is

PHP message: PHP Fatal error:  require_once(): Failed opening required '/var/www/system/core/CodeIgniter.php' (include_path='.:/usr/share/pear:/usr/share/php') in /var/www/html/index.php on line 301" while reading response header from upstream, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000"

server_name example.com;
        root /var/www/html/;
        error_page 404 /404.php;
        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;
        index index.html index.php;


        location / {
            try_files   $uri $uri/ /index.php;
            limit_req   zone=app burst=50;
        }

        location ~ \.php$ {
            root /var/www/html/;
            try_files $uri =404;
            fastcgi_index   index.php;
            fastcgi_intercept_errors on;
            fastcgi_pass    127.0.0.1:9000;
            fastcgi_buffer_size 128k;
            fastcgi_buffers 256 4k;
            fastcgi_busy_buffers_size 256k;
            fastcgi_temp_file_write_size 256k;
            fastcgi_read_timeout 240;

            include         fastcgi_params;
            fastcgi_param   SCRIPT_FILENAME    $document_root$fastcgi_script_name;
        }