前言：
Red Hat Linux的yum在線更新是收費的，未注冊則不能使用，這個是要填序列號激活的，解決辦法是更換為CentOS的yum。
查詢原有的yum
[root@orcl ~]# rpm -qa |grep yum
yum-plugin-fastestmirror-1.1.30-37.el6.noarch
yum-metadata-parser-1.1.2-16.el6.i686
yum-utils-1.1.30-37.el6.noarch
yum-plugin-security-1.1.30-37.el6.noarch
yum-3.2.29-75.el6.centos.noarch
yum-rhn-plugin-0.9.1-43.el6.noarch
刪除原有的yum
[root@orcl ~]# rpm -aq|grep yum|xargs rpm -e –nodeps
[root@orcl ~]# rpm -qa |grep yum
[root@orcl ~]#
查詢原有yum配置
[root@orcl ~]# whereis yum
yum: /etc/yum
[root@orcl ~]# rm -fr /etc/yum
下載需要的安裝包
http://mirrors.163.com/centos/6.8/os/i386/Packages/
系統為32的，所以我選擇i386。64的自行查找x86_64。可以使用 wget http://mirrors.163.com/centos/6.8/os/i386/Packages/yum-3.2.29-73.el6.centos.noarch.rpm 下載
yum-3.2.29-73.el6.centos.noarch.rpm
yum-plugin-fastestmirror-1.1.30-37.el6.noarch.rpm
yum-metadata-parser-1.1.2-16.el6.i686.rpm
Python-iniparse-0.3.1-2.1.el6.noarch.rpm
安裝python
[root@orcl ~]# rpm -ivh python-iniparse-….noarch.rpm
warning: python-iniparse-0.4-9.el7.noarch.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY
error: Failed dependencies:
python(abi) = 2.7 is needed by python-iniparse-0.4-9.el7.noarch
當前安裝版本與服務器不兼容，退後一個版本再試。查看當前發行版本號 cat /etc/issue
錯誤：系統位數與安裝程序包位數不一致 file /bin/ls
error: Failed dependencies:
libc.so.6()(64bit) is needed by yum-metadata-parser-1.1.2-16.el6.x86_64
libc.so.6(GLIBC_2.2.5)(64bit) is needed by yum-metadata-parser-1.1.2-16.el6.x86_64
libglib-2.0.so.0()(64bit) is needed by yum-metadata-parser-1.1.2-16.el6.x86_64
libpthread.so.0()(64bit) is needed by yum-metadata-parser-1.1.2-16.el6.x86_64
libpython2.6.so.1.0()(64bit) is needed by yum-metadata-parser-1.1.2-16.el6.x86_64
libsqlite3.so.0()(64bit) is needed by yum-metadata-parser-1.1.2-16.el6.x86_64
libxml2.so.2()(64bit) is needed by yum-metadata-parser-1.1.2-16.el6.x86_64
libxml2.so.2(LIBXML2_2.4.30)(64bit) is needed by yum-metadata-parser-1.1.2-16.el6.x86_64
重新下載32位程序包
[root@orcl ~]# rpm -ivh python-iniparse-0.3.1-2.1.el6.noarch.rpm
Preparing… ########################################### [100%]
package python-iniparse-0.3.1-2.1.el6.noarch is already installed
[root@orcl ~]# rpm -ivh yum-metadata-parser-1.1.2-16.el6.i686.rpm
Preparing… ########################################### [100%]
1:yum-metadata-parser ########################################### [100%]
[root@orcl ~]# rpm -ivh yum-3.2.29-73.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.30-37.el6.noarch.rpm
Preparing… ########################################### [100%]
1:yum-plugin-fastestmirro########################################### [ 50%]
2:yum ########################################### [100%]
[root@orcl ~]#
注意最後兩個包必需同時安裝，否則會相互依賴
更改yum源（使用網易的CentOS鏡像源）
[root@localhost yum]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# rm -rf *
[root@localhost yum.repos.d]# wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
[root@localhost yum.repos.d]# vi CentOS6-Base-163.repo
將所有 $releasever 修改為具體的版本號，我這裡寫的是6.8，這個自己打開（http://mirrors.163.com/centos）找一下就可以。
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base - 163.com
baseurl=http://mirrors.163.com/centos/6.8/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#released updates
[updates]
name=CentOS-$releasever - Updates - 163.com
baseurl=http://mirrors.163.com/centos/6.8/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - 163.com
baseurl=http://mirrors.163.com/centos/6.8/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - 163.com
baseurl=http://mirrors.163.com/centos/6.8/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib - 163.com
baseurl=http://mirrors.163.com/centos/6.8/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6清理yum緩存
yum clean all
顯示已安程序包及可安程序包
yum list
可以按要求更新程序包或安裝
yum update / yum install 包名
到此結束了，親們。
