更新阿里yum源

备份CentOS-Base.repo

cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

更新为阿里或163原

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo

清理->升级

yum clean all
yum makecache  
yum -y update

参考

https://www.cnblogs.com/ziyoufei/p/11721507.html