# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
# sed -i 's/$releasever/7/g' /etc/yum.repos.d/CentOS-Base.repo
# yum clean all
# yum list
配置redhat6 *的源其實也一樣
只需要進入到http://mirrors.aliyun.com/repo/的目錄,然后尋找Centos-6.repo
第二部:sed -i 's/$releasever/6/g' /etc/yum.repos.d/CentOS-Base.repo 把7換成6,其他都一樣。