镜像站:http://mirrors.163.com/
备份:
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
yum配置(http://mirrors.163.com/.help/CentOS7-Base-163.repo):
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
或者
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
执行yum命令:
yum clean all yum makecache