centOS安装yum阿里镜像仓库方法

1)先安装wget

yum install -y wget

2. 查询国内镜像源

打开阿里镜像http://mirrors.aliyun.com/
点击帮助：
3）下载CentOS 7的repo文件

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
#或者
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

如果提示报错wget: unable to resolve host address ‘mirrors.aliyun.com’

意思是无法解析主机地址。应该是与DNS解析有关。
DNS的解析配置文件是/etc/resolv.conf

编辑命令：vi /etc/resolv.conf

添加下面的地址（注意：我这里是私有云）

nameserver 183.221.253.100
nameserver 10.101.10.48
nameserver 10.101.51.169
nameserver 211.137.96.205

公有云一般添加google的DNS服务器和移动，电信或联通的DNS服务器，根据自己需要添加。
4）更新镜像源

清除缓存

yum clean all  

生成缓存

yum makecache
[root@localhost ~]# yum clean all

Loaded plugins: fastestmirror
Cleaning repos: base extras updates
Cleaning up everything
Cleaning up list of fastest mirrors
[root@localhost ~]# yum makecache
Loaded plugins: fastestmirror
base | 3.6 kB 00:00:00
extras | 3.4 kB 00:00:00
updates | 3.4 kB 00:00:00
(1/12): base/7/x86_64/group_gz | 155 kB 00:00:00
(2/12): extras/7/x86_64/filelists_db | 770 kB 00:00:02
(3/12): extras/7/x86_64/primary_db | 151 kB 00:00:00
(4/12): extras/7/x86_64/other_db | 640 kB 00:00:07
(5/12): updates/7/x86_64/filelists_db
.......省略