CentOS 7.6 更换阿里源和EPEL源
1、备份cd /etc/yum.repos.d/mkdir repo_bakmv *.repo repo_bak/ls备份当前源2、下载新的CentOS-Base.repo 到/etc/yum.repos.d/wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repols3、之后运行yum clean all 清除缓存，运行 yum makeca
