DB Backup Code in codeigniter

<?php
/*
*  Controller Name : Dbbackup
*  Location  : application/controllers/Dbbackup.php
*/
class Dbbackup extends CI_Controller{
function index(){
// Load the DB utility class
$this->load->dbutil();
$prefs = array(
'format'      => 'zip',             // gzip, zip, txt
'filename'    => 'backup_'.date('d_m_Y_H_i_s').'.sql',    // File name - NEEDED ONLY WITH ZIP FILES
'add_drop'    => TRUE,              // Whether to add DROP TABLE statements to backup file
'add_insert'  => TRUE,              // Whether to add INSERT data to backup file
'newline'     => "\n"               // Newline character used in backup file
);
// Backup your entire database and assign it to a variable
$backup =$this->dbutil->backup($prefs);

// Load the file helper and write the file to your server
$this->load->helper('file');
write_file('/path/to/'.'dbbackup_'.date('d_m_Y_H_i_s').'.zip', $backup);

// Load the download helper and send the file to your desktop
$this->load->helper('download');
force_download('dbbackup_'.date('d_m_Y_H_i_s').'.zip', $backup);
}
}
?>