# cd /etc/yum.repos.d
# cp CentOS-Base.repo CentOS-Base.repo_bak #备份
# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo #下载阿里源
# wget -O /etc/yum.repos.d/epel-7.repo http://mirrors.aliyun.com/repo/epel-7.repo # 下载阿里开源镜像的epel源文件
# yum clean all #清除系统所有yum源
# yum makecache #生成yum缓存
# yum repolist enabled #查看系统可用的yum源
# yum repolist all
# cp CentOS-Base.repo CentOS-Base.repo_bak #备份
# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo #下载阿里源
# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo #下载网易源
# yum makecache #生成yum缓存
# yum list | grep epel-release.noarch
# yum install epel-release.noarch #安装epel源# wget -O /etc/yum.repos.d/epel-7.repo http://mirrors.aliyun.com/repo/epel-7.repo # 下载阿里开源镜像的epel源文件
# yum clean all #清除系统所有yum源
# yum makecache #生成yum缓存
# yum repolist enabled #查看系统可用的yum源
# yum repolist all