CentOS配置yum源（补充）

这是对yum命令的补充    Yum命令

　　

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一、用Centos镜像搭建本地yum源

由于安装centos后的默认yum源为centos的官方地址，所以在国内使用很慢甚至无法访问，所以一般的做法都是把默认的yum源替换成aliyun的yum源或者163等国内的yum源(下文介绍如何配置)。
但是以上的方法都是需要网络的，当没有网络的时候就无法使用了，所以还有一个常用的方法就是用Centos的iso镜像搭建本地yum源，这样安装软件的速度就会飞快，缺点是可能有些包没有。

.安装Centos后默认的yum源如下

[root@huhy ~]# ll /etc/yum.repos.d/
total
-rw-r--r--.  root root  Dec     CentOS-Base.repo
-rw-r--r--.  root root  Dec     CentOS-CR.repo
-rw-r--r--.  root root   Dec     CentOS-Debuginfo.repo
-rw-r--r--.  root root   Dec     CentOS-fasttrack.repo
-rw-r--r--.  root root   Dec     CentOS-Media.repo
-rw-r--r--.  root root  Dec     CentOS-Sources.repo
-rw-r--r--.  root root  Dec     CentOS-Vault.repo
.把默认yum源备份(可选)

[root@huhy ~]# mkdir /opt/centos-yum.bak
[root@huhy ~]# mv /etc/yum.repos.d/* /opt/centos-yum.bak/
3.在虚拟机上挂载CentOS镜像文件

这里写图片描述

[root@huhy ~]# mount -t iso9660 /dev/sr0 /opt/centos
mount: /dev/sr0 is write-protected, mounting read-only
4.编写repo文件并指向镜像的挂载目录

[root@huhy ~]# vi /etc/yum.repos.d/local.repo
[local]
name=local
baseurl=file:///opt/centos
enabled=1
gpgcheck=0
5.清除缓存

[root@huhy ~]# yum clean all
Loaded plugins: fastestmirror
Cleaning repos: local
Cleaning up everything
Cleaning up list of fastest mirrors
[root@huhy ~]# yum makecache        //把yum源缓存到本地，加快软件的搜索好安装速度
[root@huhy ~]# yum list        //列出了3780个包

二、把默认的CentOS yum源修改成国内的aliyun yum源

阿里云官方教程：http://mirrors.aliyun.com/help/centos

1.安装Centos后默认的yum源如下

[root@huhy ~]# ll /etc/yum.repos.d/
total 32
-rw-r--r--. 1 root root 1664 Dec  9  2015 CentOS-Base.repo
-rw-r--r--. 1 root root 1309 Dec  9  2015 CentOS-CR.repo
-rw-r--r--. 1 root root  649 Dec  9  2015 CentOS-Debuginfo.repo
-rw-r--r--. 1 root root  290 Dec  9  2015 CentOS-fasttrack.repo
-rw-r--r--. 1 root root  630 Dec  9  2015 CentOS-Media.repo
-rw-r--r--. 1 root root 1331 Dec  9  2015 CentOS-Sources.repo
-rw-r--r--. 1 root root 1952 Dec  9  2015 CentOS-Vault.repo
2.把默认yum源备份(可选)

[root@huhy ~]# mkdir /opt/centos-yum.bak
[root@huhy ~]# mv /etc/yum.repos.d/* /opt/centos-yum.bak/

3.下载aliyun yum源repo文件(对应自己的系统版本下载即可)

#各系统版本repo文件对应的下载操作
CentOS 5
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo
CentOS 6
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
CentOS 7
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

[root@huhy ~]# cat /etc/redhat-release        //查看系统的版本
CentOS Linux release 7.2.1511 (Core)
[root@huhy ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
--2017-06-20 06:43:08--  http://mirrors.aliyun.com/repo/Centos-7.repo
Resolving mirrors.aliyun.com (mirrors.aliyun.com)... 112.124.140.210, 115.28.122.210
Connecting to mirrors.aliyun.com (mirrors.aliyun.com)|112.124.140.210|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2573 (2.5K) [application/octet-stream]
Saving to: ‘/etc/yum.repos.d/CentOS-Base.repo’
100%[=======================================================================================================>] 2,573       --.-K/s   in 0s
2017-06-20 06:43:08 (118 MB/s) - ‘/etc/yum.repos.d/CentOS-Base.repo’ saved [2573/2573]

4.清除缓存

[root@huhy ~]# yum clean all
Loaded plugins: fastestmirror
Cleaning repos: base extras updates
Cleaning up everything
Cleaning up list of fastest mirrors
[root@huhy ~]# yum makecache        //把yum源缓存到本地，加快软件的搜索好安装速度
[root@huhy ~]# yum list        //总共列出了9954个包
三、把默认的CentOS yum源修改成国内的163源

163官方教程：http://mirrors.163.com/.help/centos.html

1.安装Centos后默认的yum源如下

[root@huhy ~]# ll /etc/yum.repos.d/
total 32
-rw-r--r--. 1 root root 1664 Dec  9  2015 CentOS-Base.repo
-rw-r--r--. 1 root root 1309 Dec  9  2015 CentOS-CR.repo
-rw-r--r--. 1 root root  649 Dec  9  2015 CentOS-Debuginfo.repo
-rw-r--r--. 1 root root  290 Dec  9  2015 CentOS-fasttrack.repo
-rw-r--r--. 1 root root  630 Dec  9  2015 CentOS-Media.repo
-rw-r--r--. 1 root root 1331 Dec  9  2015 CentOS-Sources.repo
-rw-r--r--. 1 root root 1952 Dec  9  2015 CentOS-Vault.repo

2.把默认yum源备份(可选)

[root@huhy ~]# mkdir /opt/centos-yum.bak
[root@huhy ~]# mv /etc/yum.repos.d/* /opt/centos-yum.bak/
3.下载163 yum源repo文件

#各系统版本repo文件对应的下载操作
CentOS 5
wget -O /etc/yum.repos.d/CentOS5-Base-163.repo http://mirrors.163.com/.help/CentOS5-Base-163.repo
CentOS 6
wget -O /etc/yum.repos.d/CentOS6-Base-163.repo http://mirrors.163.com/.help/CentOS6-Base-163.repo
CentOS 7
wget -O /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
[root@huhy ~]# cat /etc/redhat-release        //查看系统的版本
CentOS Linux release 7.2.1511 (Core)
[root@huhy ~]# wget -O /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
--2017-06-20 06:29:47--  http://mirrors.163.com/.help/CentOS7-Base-163.repo
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... 200 OK
Length: 1572 (1.5K) [application/octet-stream]
Saving to: ‘/etc/yum.repos.d/CentOS7-Base-163.repo’
100%[=======================================================================================================>] 1,572       --.-K/s   in 0s
2017-06-20 06:29:47 (293 MB/s) - ‘/etc/yum.repos.d/CentOS7-Base-163.repo’ saved [1572/1572]

4.清除缓存

[root@huhy ~]# yum clean all
Loaded plugins: fastestmirror
Cleaning repos: base extras updates
Cleaning up everything
Cleaning up list of fastest mirrors
[root@huhy ~]# yum makecache        //把yum源缓存到本地，加快软件的搜索好安装速度
[root@huhy ~]# yum list        //总共列出了9951个包

四、修改yum源的优先级

ps:当既有本地yum源又有163源的时候，我们在装软件包的时候当然希望先用本地的yum源去安装，本地找不到可用的包时再使用163源去安装软件,这里就涉及到了优先级的问题，yum提供的插件yum-plugin-priorities.noarch可以解决这个问题

1.查看系统是否安装了优先级的插件

[root@huhy ~]# rpm -qa | grep yum-plugin-
yum-plugin-fastestmirror-1.1.31-34.el7.noarch
//这里看到没有安装yum-plugin-priorities.noarch这个插件
[root@huhy ~]# yum search yum-plugin-priorities
//用search查看是否有此插件可用
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
====================================================== N/S matched: yum-plugin-priorities =======================================================
yum-plugin-priorities.noarch : plugin to give priorities to packages from different repos

2.安装yum-plugin-priorities.noarch插件

[root@huhy ~]# yum -y install yum-plugin-priorities.noarch

3.查看插件是否启用

[root@huhy ~]# cat /etc/yum/pluginconf.d/priorities.conf
[main]
enabled = 1 //1为启用；0为禁用

4.修改本地yum源优先使用

[root@huhy ~]# ll /etc/yum.repos.d/
total 8
-rw-r--r--. 1 root root 2573 May 15  2015 CentOS-Base.repo
-rw-r--r--. 1 root root   67 Jun 20 06:04 local.repo
//有两个repo文件
[root@huhy ~]# vi /etc/yum.repos.d/local.repo
[local]
name=local
baseurl=file:///opt/centos
enabled=1
gpgcheck=0
priority=1
//在原基础上加入priority=1 ；数字越小优先级越高
//可以继续修改其他源的priority值，经测试仅配置本地源的优先级为priority=1就会优先使用本地源了

5.测试

配置优先级前：(使用阿里云yum源)
[root@huhy ~]# yum -y install vim
Dependencies Resolved
=================================================================================================================================================
Package                            Arch                         Version                                     Repository                     Size
=================================================================================================================================================
Installing:
vim-enhanced                       x86_64                       2:7.4.160-1.el7_3.1                         updates                       1.0 M
Updating for dependencies:
vim-common                         x86_64                       2:7.4.160-1.el7_3.1                         updates                       5.9 M
省略···

配置优先级后：(使用本地yum源)
[root@huhy ~]# yum -y install vim
Dependencies Resolved
=================================================================================================================================================
Package                                     Arch                        Version                                Repository                  Size
=================================================================================================================================================
Installing:
vim-enhanced                                x86_64                      2:7.4.160-1.el7                        local                      1.0 M
Installing for dependencies:
gpm-libs                                    x86_64                      1.20.7-5.el7                           local                       32 k
perl                                        x86_64                      4:5.16.3-286.el7                       local                      8.0 M
perl-Carp                                   noarch                      1.26-244.el7                           local                       19 k
perl-Encode                                 x86_64                      2.51-7.el7                             local                      1.5 M
perl-Exporter                               noarch                      5.68-3.el7