1、备份CentOS-Base.repo
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 http://mirrors.aliyun.com/repo/Centos-6.repo
CentOS 7
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
3、完成之后清空yum缓存,并重建yum缓存
yum clean all && yum clean metadata && yum clean dbcache && yum makecache && yum update
注:如果是阿里云的ESC云服务器,可以将第2步中源的域名从mirrors.aliyun.com改为mirrors.aliyuncs.com,不占用公网流量。