一次服务器部署系统为redhat7.4，因为redhat需要注册，故替换yum源。有阿里、网易两种方案。
以下操作均使用root。
删除redhat原有的yum源
> rpm -aq | grep yum|xargs rpm -e –nodeps
下载yum安装包
下载新的yum安装包,我这里redhat的版本是7，所以我使用contenos7的yum
网易
wget http://mirrors.163.com/centos/7/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm
wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-3.4.3-118.el7.centos.noarch.rpm
wget http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-24.el7.noarch.rpm
wget http://mirrors.163.com/centos/7/os/x86_64/Packages/python-urlgrabber-3.10-8.el7.noarch.rpm
阿里（推荐）
wget https://mirrors.aliyun.com/centos/7/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
wget https://mirrors.aliyun.com/centos/7/os/x86_64/Packages/yum-3.4.3-158.el7.centos.noarch.rpm
wget https://mirrors.aliyun.com/centos/7/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-45.el7.noarch.rpm
wget https://mirrors.aliyun.com/centos/7/os/x86_64/Packages/yum-utils-1.1.31-45.el7.noarch.rpm
wget https://mirrors.aliyun.com/centos/7/os/x86_64/Packages/python-urlgrabber-3.10-8.el7.noarch.rpm
安装yum软件包
rpm -ivh python-iniparse-0.4-9.el7.noarch.rpm
rpm -ivh yum-metadata-parser-1.1.4-10.el7.x86_64.rpm yum-3.4.3-118.el7.centos.noarch.rpm yum-plugin-fastestmirror-1.1.31-24.el7.noarch.rpm --force --nodeps
其中python也需要，安装会有依赖的问题，所以加上--force参数强制安装
更新yum库地址
网易的CentOS镜像源
cd /etc/yum.repos.d/
wget [http://mirrors.163.com/.help/CentOS7-Base-163.repo](http://mirrors.163.com/.help/CentOS6-Base-163.repo)
阿里CentOS镜像源
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
修改以上文件将所有$releasever替换为7
vim /etc/yum.repos.d/CentOS7-Base-163.repo 【Centos-7.repo】
执行：
:%s/$releaserver/7/g
使设置生效
yum clean all #清理yum缓存，使设置生效
yum makecache #将服务器上的软件包信息缓存到本地,以提高搜索安装软件的速度
yum install fcitx #测试yum是否可用
下面记录下yum的常用命令
查询命令
yum search keyword ->搜索
yum list(all|installed|recent|updates) ->列出全部，安装的，最近的，软件更新的rpm包
yum info packagename -> 显示指定软件的信息
yum whatprovides filename -> 查询哪个rpm软件包含目标文件
基本命令
yum install rpmpackagename -> 安装指定的rpm包
yum remove rpmpackagename ->卸载指定的rpm包
yum update rpmpackagename ->升级指定rpm包
附录
网易
# 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-7.4.1708 - Base - 163.com
baseurl=http://mirrors.163.com/centos/7.4.1708/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=7.4.1708&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-7.4.1708 - Updates - 163.com
baseurl=http://mirrors.163.com/centos/7.4.1708/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=7.4.1708&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-7.4.1708 - Extras - 163.com
baseurl=http://mirrors.163.com/centos/7.4.1708/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=7.4.1708&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-7.4.1708 - Plus - 163.com
baseurl=http://mirrors.163.com/centos/7.4.1708/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=7.4.1708&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-7
#contrib - packages by Centos Users
[contrib]
name=CentOS-7.4.1708 - Contrib - 163.com
baseurl=http://mirrors.163.com/centos/7.4.1708/cr/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=7.4.1708&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-7
阿里
# 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 - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7./os/$basearch/
[http://mirrors.aliyuncs.com/centos/7./os/$basearch/](http://mirrors.aliyuncs.com/centos/7./os/$basearch/)
[http://mirrors.cloud.aliyuncs.com/centos/7./os/$basearch/](http://mirrors.cloud.aliyuncs.com/centos/7./os/$basearch/)
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-7\. - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7./updates/$basearch/
[http://mirrors.aliyuncs.com/centos/7./updates/$basearch/](http://mirrors.aliyuncs.com/centos/7./updates/$basearch/)
[http://mirrors.cloud.aliyuncs.com/centos/7./updates/$basearch/](http://mirrors.cloud.aliyuncs.com/centos/7./updates/$basearch/)
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-7\. - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7./extras/$basearch/
[http://mirrors.aliyuncs.com/centos/7./extras/$basearch/](http://mirrors.aliyuncs.com/centos/7./extras/$basearch/)
[http://mirrors.cloud.aliyuncs.com/centos/7./extras/$basearch/](http://mirrors.cloud.aliyuncs.com/centos/7./extras/$basearch/)
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-7\. - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7./centosplus/$basearch/
[http://mirrors.aliyuncs.com/centos/7./centosplus/$basearch/](http://mirrors.aliyuncs.com/centos/7./centosplus/$basearch/)
[http://mirrors.cloud.aliyuncs.com/centos/7./centosplus/$basearch/](http://mirrors.cloud.aliyuncs.com/centos/7./centosplus/$basearch/)
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#contrib - packages by Centos Users
[contrib]
name=CentOS-7\. - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7./contrib/$basearch/
[http://mirrors.aliyuncs.com/centos/7./contrib/$basearch/](http://mirrors.aliyuncs.com/centos/7./contrib/$basearch/)
[http://mirrors.cloud.aliyuncs.com/centos/7./contrib/$basearch/](http://mirrors.cloud.aliyuncs.com/centos/7./contrib/$basearch/)
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
备注：个人博客同步至。