https://blog.wongcw.com/2019/10/15/linux%e6%9b%9d%e5%87%basudo%e6%8f%90%e6%ac%8a%e6%bc%8f%e6%b4%9e%e5%8f%97%e9%99%90%e7%94%a8%e6%88%b6%e4%ba%a6%e5%8f%af%e9%81%8b%e8%a1%8croot%e5%91%bd%e4%bb%a4/