public static function delete($id_)
 {
     Logger::debug('main', 'Starting Abstract_VDI::delete for \'' . $id_ . '\'');
     $SQL = SQL::getInstance();
     if (!Abstract_VDI::exists($id_)) {
         Logger::error('main', 'Abstract_VDI::delete(\'' . $id_ . '\') virtual machine does not exist');
         return false;
     }
     $SQL->DoQuery('DELETE FROM #1 WHERE @2 = %3 LIMIT 1', self::table, 'id', $id_);
     return true;
 }