首先把selinux给禁用掉，不禁用有时候会各种各样的错误
查看
[root@localhost ~]# getenforce
Enforcing
永久关闭
[root@localhost ~]# vi /etc/selinux/config
修改
SELINUX=enforcingSELINUX=disabled
设置后需要重启才能生效
[root@localhost ~]# reboot
先执行
[root@localhost ~]# curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo [root@localhost ~]# yum -y install yum-utils [root@localhost ~]# yum install wget
备份
[root@bogon ~]# cd /etc/yum.repos.d/ [root@bogon yum.repos.d]# mkdir repo_bak [root@bogon yum.repos.d]# mv *.repo repo_bak/ [root@bogon yum.repos.d]# ls repo_bak
[root@localhost ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
[root@localhost ~]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# ls
CentOS-Base.repo repo_bak
[root@localhost yum.repos.d]# yum clean all
[root@localhost yum.repos.d]# yum makecache
原文：https://www.cnblogs.com/reasonzzy/p/11143737.html