This system is not registered with RHN 解决方案（redhat配置yum问题）与附表(配置yum)
 
1、卸载redhat的yum组件
[root@doudou ~]# rpm -qa | grep yum | xargs rpm -e --nodeps

2、下载centos的yum组件
方法1：
[root@doudou ~]# wget  http://centos.ustc.edu.cn/centos/5/os/i386/CentOS/yum-metadata-parser-1.1.2-3.el5.centos.i386.rpm
[root@doudou ~]# wget  http://centos.ustc.edu.cn/centos/5/os/i386/CentOS/yum-fastestmirror-1.1.16-16.el5.centos.noarch.rpm
[root@doudou ~]# wget  http://centos.ustc.edu.cn/centos/5/os/i386/CentOS/yum-3.2.22-37.el5.centos.noarch.rpm
方法2：
从安装盘中，提取需要的3个包，注意系统的版本。
我的系统是64位的
[root@doudou ~]# uname -a
Linux doudou 2.6.18-194.el5 #1 SMP Tue Mar 16 21:52:39 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux

yum-3.2.22-37.el5.centos.noarch.rpm
yum-fastestmirror-1.1.16-16.el5.centos.noarch.rpm
yum-metadata-parser-1.1.2-3.el5.centos.x86_64.rpm

3、安装centos的yum组件
[root@doudou ~]# rpm -ivh *.rpm

4、备份/etc/yum.repos.d/下面的Redhat源
[root@doudou ~]#mv rhel-debuginfo.repo rhel-debuginfo.repo.bak
[root@doudou ~]#mv rhel-source.repo rhel-source.repo.bak
 
5、下载更新5版本源，并存放在系统目录中
方法1：
[root@doudou ~]# wget http://docs.linuxtone.org/soft/lemp/CentOS-Base.repo
方法2：
vi /etc/yum.repos.d/CentOS-Base.repo , 从网上COPY，然后进行修改
放在目录 /etc/yum.repos.d/ 下面
 
-- 下载更新6版本源
[base]
name=CentOS-6 - Base - 163.com
baseurl=http://mirrors.163.com/centos/6/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6


#released updates
[updates]
name=CentOS-6 - Updates - 163.com
baseurl=http://mirrors.163.com/centos/6/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6


#additional packages that may be useful
[extras]
name=CentOS-6 - Extras - 163.com
baseurl=http://mirrors.163.com/centos/6/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6


#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-6 - Plus - 163.com
baseurl=http://mirrors.163.com/centos/6/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6


#contrib - packages by Centos Users
[contrib]
name=CentOS-6 - Contrib - 163.com
baseurl=http://mirrors.163.com/centos/6/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6


6、生成缓存并进行安装
[root@doudou ~]# yum makecache

附表：配置YUM，使用ISO镜像

1、 挂载镜像
mount -o loop rhel-server-5.5-x86_64-dvd.iso /guazai
2、找到RPM包集的目录
/guazai/Server
3、修改yum配置文件
vi /etc/yum.repos.d/CentOS-Base.repo
有3处需要修改
a)修改：baseurl=file:///guazai/Server
b)修改：gpgcheck=0
c)修改：#gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
4、使用yum
yum clean all
yum list
yum install *.rpm