CENTOS_7_x86_64换yum源

1：查看当前yum源：

yum repolist

2：更换yum源

2-1：备份原yum源

cp -a /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak

2-2：下载华为云yum源

wget -O /etc/yum.repos.d/CentOS-Base.repo https://repo.huaweicloud.com/repository/conf/CentOS-7-reg.repo

2-3：清理原yum源缓存

yum clean all

2.4:建立元数据

yum makecache