CentOS6可用源

echo '[base] 
name=CentOS-$releasever - Base 
baseurl=http://mirror.nsc.liu.se/centos-store/6.10/os/$basearch/  
gpgcheck=1 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6'>/etc/yum.repos.d/CentOS-Base.repo

CentOS已经停止维护，还是建议尽快升级系统吧。