rpm -Uvh sqlite-2.8.16-1.2.el4.rf.i386.rpm python-elementtree-1.2.6-7.el4.rf.i386.rpm \
python-sqlite-1.0.1-1.2.el4.rf.i386.rpm python-urlgrabber-2.9.7-1.2.el4.rf.noarch.rpm
去
http://www.rpmfind.net/
搜索yum
然后安装。
rpm -ivh yum-2.4.2-0.4.el4.rf.noarch.rpm
然后导入一个GPG-KEY
rpm --import /usr/share/rhn/RPM-GPG-KEY
还要修改一下/etc/yum.repos.d/CentOS-Base.repo才可以yum升级，把/etc/yum.repos.d/CentOS-Base.repo的内容替换为：
[base]
name=CentOS-$releasever - Base
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#released updates
[update]
name=CentOS-$releasever - Updates
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#released updates
[update]
name=CentOS-$releasever - Updates
mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=updates
#baseurl=http://mirror.centos.org/centos/4/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#packages used/produced in the build but not released
[addons]
name=CentOS-4 - Addons
mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=addons
#baseurl=http://mirror.centos.org/centos/4/addons/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#additional packages that may be useful
[extras]
name=CentOS-4 - Extras
mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=extras
#baseurl=http://mirror.centos.org/centos/4/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-4 - Plus
mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=centosplus
#baseurl=http://mirror.centos.org/centos/4/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#contrib - packages by Centos Users
[contrib]
name=CentOS-4 - Contrib
mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=contrib
#baseurl=http://mirror.centos.org/centos/4/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
解决yum GPG问题
rpm --import
http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
然后现在就可以进行升级了
yum -y update