CentOS

1. 进入到repo的存放位置

   [root@centos ~]# cd /etc/yum.repos.d/

2. 2

    

   下载网易的repo

   [root@centos yum.repos.d]# wget http://mirrors.163.com/.help/CentOS6-Base-163.repo

    

3. 3

   将原来的repo备份

   [root@centos yum.repos.d]# mv CentOS-Base.repo CentOS-Base.repo.bak

4. 4

   将网易的repo更改为默认的源

   [root@centos yum.repos.d]# mv CentOS6-Base-163.repo CentOS-Base.repo

5. 5

    

   生成缓存

   [root@centos yum.repos.d]# yum clean all

CentOS Linux release 7.1.1503  kernel-3.10.0-229.el7.x86_64

CentOS Linux release 7.2.1511    kernel-3.10.0-327.el7.x86_64 

CentOS Linux release 7.3.1611    kernel-3.10.0-514.el7.x86_64
CentOS Linux release 7.4.1708    kernel 3.10.0-693.el7.x86_64

CentOS Linux release 7.5.1804    kernel-3.10.0-862.14.4.el7.x86_64(用着感觉不好，不推荐使用这个版本）

CentOS Linux release 7.6.1810    kernel-3.10.0-957.1.3.el7.x86_64

CentOS Linux release 7.7.1908    kernel-3.10.0-1062.4.1.el7.x86_64

CentOS Linux release 7.8        3.10.0-1127