【教程】CentOS 5.6 yum 更新源

很多组件如果改一下yum更新源基本无法正常更新
1、修改

/etc/yum.repos.d/CentOS-Base.repo

文件

[base] 
name=CentOS-$releasever - Base 
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os 
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ 
gpgcheck=1 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
#released updates 
[updates] 
name=CentOS-$releasever - Updates 
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates 
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/ 
gpgcheck=1 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful 
[extras] 
name=CentOS-$releasever - Extras 
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras 
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/ 
gpgcheck=1 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
#additional packages that extend functionality of existing packages 
[centosplus] 
name=CentOS-$releasever - Plus 
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus 
#baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/ 
gpgcheck=1 
enabled=0 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
#contrib - packages by Centos Users 
[contrib] 
name=CentOS-$releasever - Contrib 
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib 
#baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/ 
gpgcheck=1 
enabled=0 
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

2、导入RPG-KEY文件

rpm -import http://ftp.sjtu.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5

3、yum update

yum clean all