介绍yum网络源，所以决定尝试一下CentOS的网络源，这样在安装依赖包时就会方便很多，由于redhat 的更新包只对注册的用户生效，所以需要自己手动更改成CentOS 的更新包，CentOS几乎和redhat是一样的，所以无需担心软件包是否可安装，安装之后是否有问题，另外CentOS公司去年已经被Redhat 收购了，下面是安装步骤。
1、首先查看redhat 7.0系统本身所安装的那些yum 软件包：
[root@linuxprobe ~]# rpm -qa | grep yum
yum-utils-1.1.31-24.el7.noarch yum-langpacks-0.4.2-3.el7.noarch
yum-metadata-parser-1.1.4-10.el7.x86_64
yum-rhn-plugin-2.0.1-4.el7.noarch
PackageKit-yum-0.8.9-11.el7.x86_64
yum-3.4.3-118.el7.noarch
2、卸载这些软件包；
[root@linuxprobe ~]# rpm -e yum-3.4.3-118.el7.noarch --nodeps
[root@linuxprobe ~]# rpm -e yum-utils-1.1.31-24.el7.noarch --nodeps
[root@linuxprobe ~]# rpm -e yum-rhn-plugin-2.0.1-4.el7.noarch --nodeps
[root@linuxprobe ~]# rpm -e yum-metadata-parser-1.1.4-10.el7.x86_64 --nodeps
[root@linuxprobe ~]# rpm -e yum-langpacks-0.4.2-3.el7.noarch --nodeps
[root@linuxprobe ~]# rpm -e PackageKit-yum-0.8.9-11.el7.x86_64 --nodeps
3、保证本机电脑能上网；
[root@linuxprobe ~]# ping www.baidu.co
PING www.a.shifen.com (61.135.169.121) 56(84) bytes of data.
64 bytes from 61.135.169.121: icmp_seq=1 ttl=53 time=31.8 ms
64 bytes from 61.135.169.121: icmp_seq=2 ttl=53 time=31.9 ms
64 bytes from 61.135.169.121: icmp_seq=3 ttl=53 time=32.0 ms
4、进入以下网站上面查看软件包的版本是否升级或者找到自己系统所对应的文件包版本更新；
网易163网络源地址：http://mirrors.163.com/
CentOS网络源地址：http://centos.ustc.edu.cn/centos/
5、找到自己所需要的版本下载：
[root@Linuxprobe ~]# wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-3.4.3-118.el7.centos.noarch.rpm
--2016-01-17 20:43:15-- http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-3.4.3-118.el7.centos.noarch.rpm
Resolving mirrors.163.com (mirrors.163.com)... 123.58.173.185, 123.58.173.186
Connecting to mirrors.163.com (mirrors.163.com)|123.58.173.185|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2016-01-17 20:43:15 ERROR 404: Not Found. //如果找不到，是安装包更新了，你可以到这个网站
http://mirrors.163.com/centos/7/os/x86_64/Packages/复制下载链接，然后再下载下来；
[root@linuxprobe ~]# wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-3.4.3-
132.el7.centos.0.1.noarch.rpm
[root@linuxprobe ~]# wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
[root@linuxprobe ~]# wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-utils-1.1.31-34.el7.noarch.rpm
[root@linuxprobe ~]# wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-updateonboot-1.1.31-34.el7.noarch.rpm[root@linuxprobe ~]# wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-34.el7.noarch.rpm
6、查看下载完成结果；
[root@linuxprobe ~]# ls
yum-3.4.3-132.el7.centos.0.1.noarch.rpm
yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
yum-plugin-fastestmirror-1.1.31-34.el7.noarch.rpm
yum-updateonboot-1.1.31-34.el7.noarch.rpm
yum-utils-1.1.31-34.el7.noarch.rpm
7、安装软件包：
[root@Linuxprobe ~]# rpm -ivh yum-*
warning: yum-3.4.3-132.el7.centos.0.1.noarch.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY Preparing... ################################# [100%]
Updating / installing...
1:yum-metadata-parser-1.1.4-10.el7 ################################# [ 20%]
2:yum-plugin-fastestmirror-1.1.31-3 ################################# [ 40%]
3:yum-3.4.3-132.el7.centos.0.1 ################################# [ 60%]
4:yum-updateonboot-1.1.31-34.el7 ################################# [ 80%]
5:yum-utils-1.1.31-34.el7 ################################# [100%]
8、新建repo 配置文件；
[root@linuxprobe ~]# vim /etc/yum.repos.d/CentOS-Base.repo
#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-$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 extend functionality 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
9、至此YUM 网络源已经安装完成；
[root@linuxprobe ~]# yum clean all
10、测试安装是否正常；
[root@Linuxprobe ~]# yum -y install lftp
Loaded plugins: fastestmirror, product-id, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package lftp.x86_64 0:4.4.8-7.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved ======================================================================
Package Arch Version Repository Size
======================================================================
Installing: lftp x86_64 4.4.8-7.el7 base 750 k
Transaction Summary
======================================================================
Install 1 Package
………………省略部分安装过程………………
Installed:
lftp.x86_64 0:4.4.8-7.el7
Complete!到这里安装完成，以后安装所需包，可以不用本地yum源了，直接使用网络yum源。
本文转载自：http://www.linuxprobe.com/redhat-7-use-centos-yum-network-sources/
