借鉴https://blog.csdn.net/u011775882/article/details/110923820
在centos下执行几条命令即可 切换root账户
sed -i “s|enabled=1|enabled=0|g” /etc/yum/pluginconf.d/fastestmirror.conf
备份现有repo仓库
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
下载并使用阿里云仓库repo
curl -o /etc/yum.repos.d/CentOS-Base.repo https://www.xmpan.com/Centos-6-Vault-Aliyun.repo
更新yum
yum clean all
yum makecache
解决。