I am trying to upload a file using codeigniters file upload library. But I am getting this error "The upload path does not appear to be valid.". But the path I am using is absolute path. The permission of the folder is 0666. Here is the code, given below - 

```
$this->load->library('upload');
            $this->upload->initialize(array(
                "upload_path" => '/var/www/html/educorp/images/students/',
                "overwrite" => TRUE,
                "encrypt_name" => TRUE,
                "remove_spaces" => TRUE,
                "allowed_types" => "jpg|jpeg|png",
                "max_size" => 300,
                "xss_clean" => FALSE
            ));
            if($this->upload->do_multi_upload('pictures')){
                echo 'done';
            } else{
                $this->session->set_flashdata('errors', true);
                $this->session->set_flashdata('messages', $this->upload->display_errors());
                redirect('student/show_upload_pictures_form');
            }

```