缺省yum源的服務器通常在國外，安裝時速度比較慢。為了提高安裝rpm包的速度，可以將yum源配置為國內的阿里repo。
1、先備份系統原有的repo
[root@localhost ~]#cd /etc/yum.repos.d/
[root@localhost yum.repos.d]#ls
CentOS-Base.repo CentOS-Debuginfo.repo CentOS-Media.repo CentOS-Vault.repo webtatic-archive.repo webtatic-testing.repo
CentOS-CR.repo CentOS-fasttrack.repo CentOS-Sources.repo epel.repo
[root@localhost yum.repos.d]#mkdir backup
[root@localhost yum.repos.d]# mv * ./backup/
2、獲取阿里centos7的base-repo
[root@localhost yum.repos.d]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
[root@localhost yum.repos.d]# ls
backup CentOS-Base.repo
3、清除並重新生成yum cache
[root@localhost yum.repos.d]# yum clean all
[root@localhost yum.repos.d]# yum makecache
4、測試一下新的yum源是否可用
[root@localhost yum.repos.d]# yum install -y screen
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
Resolving Dependencies
--> Running transaction check
---> Package screen.x86_64 0:4.1.0-0.25.20120314git3c2946.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==================================================================================================================================================
Package Arch Version Repository Size
==================================================================================================================================================
Installing:
screen x86_64 4.1.0-0.25.20120314git3c2946.el7 base 552 k
Transaction Summary
==================================================================================================================================================
Install 1 Package
Total download size: 552 k
Installed size: 914 k
Downloading packages:
screen-4.1.0-0.25.20120314git3c2946.el7.x86_64.rpm | 552 kB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : screen-4.1.0-0.25.20120314git3c2946.el7.x86_64 1/1
Verifying : screen-4.1.0-0.25.20120314git3c2946.el7.x86_64 1/1
Installed:
screen.x86_64 0:4.1.0-0.25.20120314git3c2946.el7
Complete!
5、獲取阿里centos7的epel-repo
[root@localhost yum.repos.d]# wget https://mirrors.aliyun.com/repo/epel-7.repo
6、清除並創建cache
[root@localhost yum.repos.d]# ls
backup CentOS-Base.repo epel-7.repo
[root@localhost yum.repos.d]# yum clean all
[root@localhost yum.repos.d]# yum makecache
至此，大功告成！！！