yum配置
/etc/yum.conf 主配置
/etc/yum.repo.d/ 仓库配置
redhat yum在线下载需要购买商业认证。 可以使用centos，可直接使用centos的yum源进行安装。
国内 rhel5配置源：
[base]
name=centos-5 - Base
baseurl=http://centos.ustc.edu.cn/centos/5/os/i386/
# the other site: http://centos.candishosting.com.cn/centos/5/os/i386/
# you can find more site in: http://www.centos.org/modules/tinycontent/index.php?id=13
enabled=1
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#released updates
[update]
name=CentOS-5 - Updates
baseurl=http://mirror.centos.org/centos/5/updates/i386/
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#packages used/produced in the build but not released
[addons]
name=CentOS-5 - Addons
baseurl=http://mirror.centos.org/centos/5/addons/$basearch/
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful
[extras]
name=CentOS-5 - Extras
baseurl=http://mirror.centos.org/centos/5/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-5 - Plus
baseurl=http://mirror.centos.org/centos/5/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#contrib - packages by Centos Users
[contrib]
name=CentOS-5 - Contrib
baseurl=http://mirror.centos.org/centos/5/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#packages in testing
[testing]
name=CentOS-5 - Testing
baseurl=http://mirror.centos.org/centos/5/testing/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
rpm --import http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5
yum clean all
yum update
