https://www.haedongg.net/2021/08/02/linuxcentos7-%ea%b0%80%ec%83%81-%eb%84%a4%ed%8a%b8%ec%9b%8c%ed%81%ac-%ec%9d%b8%ed%84%b0%ed%8e%98%ec%9d%b4%ec%8a%a4-%ec%b6%94%ea%b0%80/