首先，rhel5系统安装的时候其实已经有yum了，只是因为如果用官方的网站更新的话除非你是用钱买的rhel5.否则它会提示注册之类的。所以只要把
yum的更新地址改成开源的就行了。而限定yum更新地址的文件在/etc/yum.repos.d/里。先把它们改成备份文件，即在后面加.bak。
[root@killgoogle ~]# mv /etc/yum.repos.d/rhel-debuginfo.repo /etc/yum.repos.d/rhel-debuginfo.repo.bak [root@killgoogle ~]# mv /etc/yum.repos.d/rpmforge.repo.rpmnew /etc/yum.repos.d/rpmforge.repo.rpmnew.bak
建立新的配置文件：
[root@killgoogle ~]# cd /etc/yum.repos.d [root@killgoogle ~]# touch rhel-debuginfo.repo [root@killgoogle ~]# touch mirrors-rpmforge [root@killgoogle ~]# touch rpmforge.repo
往新的配置文件写东西：
[root@killgoogle ~]#vi rhel-debuginfo.repo [base] name=CentOS-5 - Base #mirrorlist=http://mirrorlist.centos.org/?release=$releasever5&arch=$basearch& repo=os #baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ baseurl=http://ftp.sjtu.edu.cn/centos/5/os/$basearch/ gpgcheck=1 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #released updates [update] name=CentOS-5 - Updates #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=updates baseurl=http://ftp.sjtu.edu.cn/centos/5/updates/$basearch/ gpgcheck=1 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #packages used/produced in the build but not released [addons] name=CentOS-5 - Addons #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=addons baseurl=http://ftp.sjtu.edu.cn/centos/5/addons/$basearch/ gpgcheck=1 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #additional packages that may be useful [extras] name=CentOS-5 - Extras #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=extras baseurl=http://ftp.sjtu.edu.cn/centos/5/extras/$basearch/ gpgcheck=1 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-5 - Plus #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=centosplus baseurl=http://ftp.sjtu.edu.cn/centos/5/centosplus/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #contrib - packages by Centos Users [contrib] name=CentOS-5 - Contrib #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=contrib baseurl=http://ftp.sjtu.edu.cn/centos/5/contrib/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 # vi dag.repo [dag] name=Dag RPM Repository for RHEL5 baseurl=http://ftp.riken.jp/Linux/dag/redhat/el5/en/$basearch/dag/ enabled=1 gpgcheck=1 gpgkey=http://ftp.riken.jp/Linux/dag/packages/RPM-GPG-KEY.dag.txt
修改第二个配置文件：
[root@killgoogle ~]vi mirrors-rpmforge http://apt.sw.be/redhat/el5/en/$ARCH/dag http://archive.cs.uu.nl/mirror/dag.wieers/redhat/el5/en/$ARCH/dag http://ftp2.lcpe.uni-sofia.bg/freshrpms/pub/dag/redhat/el5/en/$ARCH/dag #http://ftp.heanet.ie/pub/freshrpms/pub/dag/redhat/el5/en/$ARCH/dag http://ftp-stud.fht-esslingen.de/dag/redhat/el5/en/$ARCH/dag http://mirror.cpsc.ucalgary.ca/mirror/dag/redhat/el5/en/$ARCH/dag http://mirrors.ircam.fr/pub/dag/redhat/el5/en/$ARCH/dag http://rh-mirror.linux.iastate.edu/pub/dag/redhat/el5/en/$ARCH/dag http://rpmfind.net/linux/dag/redhat/el5/en/$ARCH/dag http://wftp.tu-chemnitz.de/pub/linux/dag/redhat/el5/en/$ARCH/dag http://www.mirrorservice.org/sites/apt.sw.be/redhat/el5/en/$ARCH/dag
修改第三个配置文件：
[root@killgoogle ~]# vi rpmforge.repo # Name: RPMforge RPM Repository for Red Hat Enterprise 5 - dag # URL: http://rpmforge.net/ [rpmforge] name = Red Hat Enterprise $releasever - RPMforge.net - dag #baseurl = http://apt.sw.be/redhat/el5/en/$basearch/dag mirrorlist = http://apt.sw.be/redhat/el5/en/mirrors-rpmforge #mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge enabled = 1 protect = 0 gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag gpgcheck = 1
如果风速慢的话可以通过增加yum的超时时间，这样就不会总是因为超时而退出。
[root@killgoogle ~]vi /etc/yum.conf
加上这么一句：timeout=120
到这里配置差不多就完了。还有一个包需要安装：rpmforge-release-0.3.6-1.el5.rf.i386.rpm
如果不安装的话有可能会出现以下错误：GPG key retrieval failed: [Errno 5] OSError: [Errno 2] 没有那个文件或目录: '/etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag'
到http://rpmfind.net/linux/RPM/找到这个包，然后
[root@killgoogle ~]rpm -ivh rpmforge-release-0.3.6-1.el5.rf.i386.rpm
接下来就是输入KEY了。
[root@killgoogle ~] rpm --import http://mirror.be10.com/centos/RPM-GPG-KEY-CentOS-5
这样基本上yum就可以用了。不过如果觉得不爽的话还可以优化：
加速yum
[root@killgoogle ~]yum install yum-fastestmirror yum-presto
指定或去掉软件源的mirror:
可以在baseurl中将比较慢的mirror去掉
你的yum镜像的速度测试记录文件：
/var/cache/yum/timedhosts.txt
yum Existing lock 错误的解决办法
如果系统启动的时候， yum 出现Existing lock /var/run/yum.pid: another copy is running as pid 3380. Aborting. 可以用下面的办法解决：
[root@killgoogle ~]/etc/init.d/yum-updatesd stop
也可以用以下方法：
[root@killgoogle ~]rm -f /var/run/yum.pid
主要原因就是yum在自动更新只要关掉它就可以了
如果有什么建议联系我哦：
hi.baidu.com/18187949/
完了。现在就可以测试能不能用了哦：
[root@killgoogle ~]yum install mplayer
这是安装mplayer如果要删除则是：
[root@killgoogle ~]yum remove mplayer