?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误"

一、问题描述

Centos7使用yum命令失效，报错：Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误"

二、解决方案

查询了好多种方法，有的说是DNS的问题，有的说是防火墙的问题，有的说是/etc/yum.repos.d/CentOS-Base.repo的问题。

1）DNS的问题

1.1 检查 /etc/sysconfig/network-scripts/ifcfg-ens33 配置文件

将ONBOOT=NO 改成YES，并重启网络服务 service restart network

1.2 检查有没有配置/etc/resolv.conf

2）防火墙的问题

2.1 检查防火墙状态 systemctl status firewalld

2.2 关闭防火墙 systemctl stop firewalld

3）/etc/yum.repos.d/CentOS-Base.repo的问题

3.1 sudo vim /etc/yum.repos.d/CentOS-Base.repo 将 mirrorList都注释掉，将baseurl都取消注释, :wq 保存修改。注意：在修改之前先备份原文件 mv CentOS-Base.repo ./CentOS-Base.repo.bak

3.2.执行 sudo yum update 更新软件包列表,这一步带来的效果是自动生成缓存。

3.3.恢复 CentOS-Base.repo到原始状态（baseurl注释掉，mirrorList取消注释）

3.4.继续执行sudo yum install xxx 一切恢复正常。

4）清空yum缓存的操作

yum clean all

yum makecache

　　备注

　　　　yum 会把下载的软件包和header存储在cache中(默认路径/var/cache/yum/)，而不自动删除。如果觉得占用磁盘空间，可以使用yum clean指令进行清除，更精确的用法是yum clean headers清除header，yum clean packages清除下载的rpm包，yum clean all全部清除。

三、最终解决办法

使用阿里云或其他国内镜像源

1）更新YUM仓库源为阿里云镜像源：

1	`sudo vi /etc/yum.repos.d/CentOS-Base.repo`

2）将内容替换成下面

[base]
name=CentOS-$releasever - Base - mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
 
[updates]
name=CentOS-$releasever - Updates - mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
 
[extras]
name=CentOS-$releasever - Extras - mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
 
[centosplus]
name=CentOS-$releasever - Plus - mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

3）清理并重建缓存

sudo yum clean all
sudo yum makecache
sudo yum update

4）也可以不用上面2）的代码，直接下载最新的CentOS-Base.repo文件

　CentOS 5
 
　　　　wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo
 
　　　　或者
 
　　　　curl -o /etc/yum.repos.d/CentOS-Base.repo 
 
  
 
 
 
　　　　CentOS 6
 
　　　　wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
 
　　　　或者
 
　　　　curl -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
 
　　　　或者
 
　　　　curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

如果以上还是无法解决问题，在执行yum makecache命令后，报错：

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock32 error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"
需要注意报错的最后一行：

那么尝试将如下内容追加到 /etc/yum.repos.d/CentOS-Base.repo 中

[centos-sclo-rh]
name=CentOS-7 - SCLo rh
baseurl=http://vault.centos.org/centos/7/sclo/$basearch/rh/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-SCLo
 
[centos-sclo-sclo]
name=CentOS-7 - SCLo sclo
baseurl=http://vault.centos.org/centos/7/sclo/$basearch/sclo/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-SCLo

最终的CentOS-Base.repo内容如下：

# 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-$releasever - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/os/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
 
#released updates 
[updates]
name=CentOS-$releasever - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
 
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/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-$releasever - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/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-$releasever - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
 
[centos-sclo-rh]
name=CentOS-7 - SCLo rh
baseurl=http://vault.centos.org/centos/7/sclo/$basearch/rh/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-SCLo
 
[centos-sclo-sclo]
name=CentOS-6.10 - SCLo sclo
baseurl=http://vault.centos.org/centos/7/sclo/$basearch/sclo/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-SCLo