Redhat默认自带的yum源需要注册，才能更新，报错信息如下：
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
注：需要提前看一下自己linu系统版本，本文中系统版本为Redhat 7 通过这个命令可以查看版本cat /etc/redhat-release
具体步骤如下：
1、检查目前本机安装了哪些yum包
rpm -qa |grep yum
[/code]
2、删除对应自带的yum包
[code]
#（–nodeps不检查依赖，直接删除rpm包）
rpm -qa |grep yum|xargs rpm -e –nodeps
[/code]
这里还需要卸载一个依赖包
rpm -qa |grep python-urlgrabb|xargs rpm -e –nodeps
[/code]
3、下载对应的rpm包，推荐地址http://mirrors.kernel.org/centos/7/os/x86_64/Packages/
4、需要下载的包
[code]
wget http://mirrors.kernel.org/centos/7/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
wget http://mirrors.kernel.org/centos/7/os/x86_64/Packages/yum-3.4.3-154.el7.centos.noarch.rpm
wget http://mirrors.kernel.org/centos/7/os/x86_64/Packages/python-urlgrabber-3.10-8.el7.noarch.rpm
wget http://mirrors.kernel.org/centos/7/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-42.el7.noarch.rpm
wget http://mirrors.kernel.org/centos/7/os/x86_64/Packages/yum-rhn-plugin-2.0.1-9.el7.noarch.rpm
[/code]
5、安装（注意安装顺序不能错）
[code]
rpm -ivh yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
rpm -ivh –force –nodeps yum-3.4.3-154.el7.centos.noarch.rpm python-urlgrabber-3.10-8.el7.noarch.rpm yum-plugin-fastestmirror-1.1.31-42.el7.noarch.rpm
[/code]
6、删除原来的repo源
[code]
[/code]
7、建立新的源
vim /etc/yum.repos.d/CentOS-Base.repo
[code]
[base]
name=CentOS-7 – Base – 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=7&arch=$basearch&repo=os
baseurl=http://mirrors.163.com/centos/7/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-7 – Updates – 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=7&arch=$basearch&repo=updates
baseurl=http://mirrors.163.com/centos/7/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-7 – Extras – 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=7&arch=$basearch&repo=extras
baseurl=http://mirrors.163.com/centos/7/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extendfunctionality of existing packages
[centosplus]
name=CentOS-7 – Plus – 163.com
baseurl=http://mirrors.163.com/centos/7/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
8、最后清一下缓存
[code]
[/code]
9、在第5步的时候，需要依赖rpm对应版本的安装包，考虑到如果卸载了rpm就没法安装了，所以用了–force –nodeps来强制安装，所以最后最好把rpm更新一下