protected function system_memory_info()
    {

        $this->system_memory_kb = array();

        exec("cat /proc/meminfo", $output);
        foreach ($output as $line) {
            $parts = explode(':', $line);

            if (empty($parts[0])) continue;
            // remove the KB sign and reduce it to a key value array
            $this->system_memory_kb[trim($parts[0])] = (int)(!empty($parts[1]) ? trim(str_replace('kB', '', $parts[1])) : null);
        }

        return true;
    }