1、什献垴淄睬么是yum，什么是yum源，常见的yum源有哪些？yum是centos下更新、管理软件的命令，也有相应的图像界面版本；yum源是yum命令去哪里胃申赜驵取安装包的地图；常见的yum源：网易、阿里云、epel等；
2、yum、rpm、repo什么关系？yum命令查询repo上配置的地址去取相应的rpm包进行安装；
3、配置下centos的DNS一个国内，一个国外vi /etc/resolv.conf nameserver 114.114.114.114nameserver 8.8.8.8
4、备份下原来的yum源cd /etc/yum.repos.d/mv CentOS-Base.repo CentOS-Base.repo_bak
5、网易鲻戟缒男yum源：wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.163.com/.h髫潋啜缅elp/CentOS7-Base-163.repoyum clean allyum makecache
6、阿里云yum源：wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repoyu罪焐芡拂m clean allyum makecache
7、epel源yum -y install epel-release yum clean allyum makecache
