RedHat5.4 使用 centOS5源更新

1.卸载HedHat5.4的yum命令 
    先查看RedHat上是否安装yum 
    
   
    删除所有的yum软件 
    rpm -qa | grep yum | xargs rpm -e --nodeps

2.下载新的yum包

wget http://vault.centos.org/5.4/os/x86_64/CentOS/yum-fastestmirror-1.1.16-13.el5.centos.noarch.rpm

wget http://vault.centos.org/5.4/os/x86_64/CentOS/yum-3.2.22-20.el5.centos.noarch.rpm

wget http://vault.centos.org/5.4/os/x86_64/CentOS/yum-updatesd-0.9-2.el5.noarch.rpm

wget http://vault.centos.org/5.4/os/x86_64/CentOS/yum-metadata-parser-1.1.2-3.el5.centos.x86_64.rpm

# rpm -ivh yum-*    #安装

# rpm -qa yum    #查看是否已经安装上
注意：yum和yum-fastestmirror相互依赖，所以同时安装即可。 

1. 在CentOS下有的时候用yum安装软件的时候最后会提示：
2. warning: rpmts_HdrFromFdno: Header V3 DSA signature: NOKEY, key ID*****
3. 这是由于yum安装了旧版本的GPG keys造成的，解决办法就是
4. 下载并导入Key
5. cd /etc/pki/rpm-gpg
6. wget http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
7. rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY*
8. 或者  一条  rpm --import http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

检测安装的 yum 是否有问题，执行命令进行测试：
yum clean all   重建yum缓存 
yum  makecache

外网的yum源
vim /etc/yum.repos.d/CentOS-Base.repo
输入一下内容

# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
baseurl=http://vault.centos.org/5.11/os/$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/$basearch/
baseurl=http://vault.centos.org/5.11/updates/$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/$basearch/
baseurl=http://vault.centos.org/5.11/extras/$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/$basearch/
baseurl=http://vault.centos.org/5.11/centosplus/$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/$basearch/
baseurl=http://vault.centos.org/5.11/contrib/$basearch/
gpgcheck=1 
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5</span></strong></span>

无视依赖关系安装 --force --nodeps   

# rpm -ivh db4-devel-4.3.29-9.fc6.i386.rpm --force --nodeps 

https://blog.csdn.net/m0_37886429/article/details/75009382