[yum] yum使用光盘安装或更新软件
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/ch-yum#s1-yum-upgrade-system
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/ch-yum#s1-yum-upgrade-system