source 163 replaced centos7yum

1. Go to the source file path　

　　cd /etc/yum.repos.d/

2. Download 163 sources

　　-The curl http: //mirrors.163.com/.help/CentOS7-Base-163.repo

3. Before the backup source

　　mv CentOS CentOS Base.repo Base.repo.bak

4.163 modify the source name

　　mv CentOS7-Base-163.repo CentOS-Base.repo

5. Clear Cache

　　yum clean all

6. yum update the local cache

　　yum makecache