redhat7.5 替换yum源

一，使用网易163开源镜像站  http://mirrors.163.com/ 
#1，查看原有yum包
rpm -qa|gerp yum

#2，卸载yum包
rpm -qa|grep yum|xargs rpm -e --nodeps
rpm -qa|grep yum

#3，创建下载路径,下载centos7.5 yum包
mkdir /tmp/pkg && cd /tmp/pkg
wget http://mirrors.163.com/centos/7.5.1804/os/x86_64/Packages/yum-3.4.3-158.el7.centos.noarch.rpm

wget http://mirrors.163.com/centos/7.5.1804/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm

wget http://mirrors.163.com/centos/7.5.1804/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-45.el7.noarch.rpm

#4，安装下载好的rpm包
rpm -ivh yum-*
rpm -qa|grep yum

#5，替换原有源
cd /etc/yum.repos.d/ && rm -rfv *

#6，下载163源

2.2 切换至/etc/目录下，并下载163镜像站内的镜像源文件 wget http://mirrors.163.com/.help/CentOS7-Base-163.repo

同样的 网址可能会变动，可以手动进入 http://mirrors.163.com/.help/centos.html，确认一下文件和版本
wget http://mirrors.163.com/.help/CentOS7-Base-163.repo

 将下载的CentOS7-Base-163.repo文件中的 $releasever 全部修改为目标版本 7.5.1804。修改完成后 如图：

#7，将下载好的文件中的 $releasever 全部修改为目标版本 7.5.1804
#为防止出错，以下为改好版本
[base]
name=CentOS-7.5.1804 - Base - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=7.5.1804&arch=$basearch&repo=os
baseurl=http://mirrors.163.com/centos/7.5.1804/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7

#released updates
[updates]
name=CentOS-7.5.1804 - Updates - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=7.5.1804&arch=$basearch&repo=updates
baseurl=http://mirrors.163.com/centos/7.5.1804/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7

#additional packages that may be useful
[extras]
name=CentOS-7.5.1804 - Extras - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=7.5.1804&arch=$basearch&repo=extras
baseurl=http://mirrors.163.com/centos/7.5.1804/extras/$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-7.5.1804 - Plus - 163.com
baseurl=http://mirrors.163.com/centos/7.5.1804/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7

#8，更新
yum clean all && yum makecache

#9，查看是否更新成功
yum repolist all