解決：Failed to download metadata for repo ‘base‘

鏡像下載、功能變數名稱解析、時間同步請點擊 阿裡雲開源鏡像站

1.先查看本機的系統信息

[root@h0436 h0436 zlong]# cat /etc/redhat-release

2.進入yum.repos.d

[root@h0436 zlong]# cd /etc/yum.repos.d

3.查看鏡像文件（看看你需要修改的哪個文件）

[root@h0436 yum.repos.d]# ls
CentOS-Base.repo         CentOS-Base.repo.bak  epel.repo
CentOS-Base.repo.backup  docker-ce.repo

4.修改文件（我的是CentOS-Base.repo.backup文件）

[root@h0436 yum.repos.d]# vim CentOS-Base.repo.backup 

5.如果你找不到在哪個文件夾，你就每個文件夾都vim 進去看看，找到CentOS-Base.repo就行

6.複製下麵這一段配置就行，按鍵盤上“i”編輯，按ESC退出。如果要保存退出就按:wq，如果不保存退出就按:q （圖中標紅的地方都是改過之後的地方）

[base]
name=CentOS-8 - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/8/os/$basearch/
        http://mirrors.aliyuncs.com/centos/8/os/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/8/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-8

#released updates 
[updates]
name=CentOS-8 - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/8/updates/$basearch/
        http://mirrors.aliyuncs.com/centos/8/updates/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/8/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-8

#additional packages that may be useful
[extras]
name=CentOS-8 - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/8/extras/$basearch/
        http://mirrors.aliyuncs.com/centos/8/extras/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/8/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-8

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-8 - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/8/centosplus/$basearch/
        http://mirrors.aliyuncs.com/centos/8/centosplus/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/8/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-8

#contrib - packages by Centos Users
[contrib]
name=CentOS-8 - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/8/contrib/$basearch/
        http://mirrors.aliyuncs.com/centos/8/contrib/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/8/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-8

7.清除緩存

[root@h0436 yum.repos.d]# yum clean all

8.載入緩存

[root@h0436 yum.repos.d]# yum makecache

本文轉自：https://blog.csdn.net/Along_168163/article/details/124338818