阿里云yum源
1、备份
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
2、下载新的CentOS-Base.repo 到/etc/yum.repos.d/
CentOS 5 wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo CentOS 6 wget -O /etc/yum.repos.d/CentOS-Base.repo https://www.xmpan.com/Centos-6-Vault-Aliyun.repo CentOS 7 wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo CentOS 8 （centos8官方源已下线，建议切换centos-vault源） wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo 非阿里云ECS用户会出现 Couldn't resolve host 'mirrors.cloud.aliyuncs.com' 信息，不影响使用。 sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
https://developer.aliyun.com/article/779734
阿里云epel源
1、备份
mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.backup
2、下载新repo 到/etc/yum.repos.d/
CentOS 5 wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-5.repo CentOS 6 wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo CentOS 7 wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo CentOS 8 yum install -y https://mirrors.aliyun.com/epel/epel-release-latest-8.noarch.rpm sed -i 's|^#baseurl=https://download.fedoraproject.org/pub|baseurl=https://mirrors.aliyun.com|' /etc/yum.repos.d/epel* sed -i 's|^metalink|#metalink|' /etc/yum.repos.d/epel*
sed -i -e '/mirrors.aliyuncs.com/d' -e '/mirrors.cloud.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
更新数据缓存：
yum clean all && yum makecache
不希望每次运行时都更新元数据，编辑/etc/yum.conf，设置
metadata_expire=never 或 metadata_expire=7d
