备份

[root@iZ2ze1e3u7m7oe426pyndaa ~]# cd /etc/yum.repos.d/
[root@iZ2ze1e3u7m7oe426pyndaa yum.repos.d]# ll
total 48
-rw-r--r-- 1 root root  635 Nov 20  2020 CentOS-AppStream.repo
-rw-r--r-- 1 root root  619 Nov 20  2020 CentOS-Base.repo
-rw-r--r-- 1 root root  701 Nov 20  2020 CentOS-centosplus.repo
-rw-r--r-- 1 root root 1329 Nov 20  2020 CentOS-CR.repo
-rw-r--r-- 1 root root  668 Nov 20  2020 CentOS-Debuginfo.repo
-rw-r--r-- 1 root root  227 Nov 20  2020 CentOS-epel.repo
-rw-r--r-- 1 root root  663 Nov 20  2020 CentOS-Extras.repo
-rw-r--r-- 1 root root  242 Nov 20  2020 CentOS-fasttrack.repo
-rw-r--r-- 1 root root  928 Nov 20  2020 CentOS-Media.repo
-rw-r--r-- 1 root root  639 Nov 20  2020 CentOS-PowerTools.repo
-rw-r--r-- 1 root root 1382 Nov 20  2020 CentOS-Sources.repo
-rw-r--r-- 1 root root   74 Nov 20  2020 CentOS-Vault.repo
[[root@iZ2ze1e3u7m7oe426pyndaa yum.repos.d]# mkdir /home/ydt/yum.repos.d.ori
[root@iZ2ze1e3u7m7oe426pyndaa yum.repos.d]# cp * /home/ydt/yum.repos.d.ori/
[root@iZ2ze1e3u7m7oe426pyndaa yum.repos.d]# ll /home/ydt/yum.repos.d.ori/
total 48
-rw-r--r-- 1 root root  635 Feb 15 14:03 CentOS-AppStream.repo
-rw-r--r-- 1 root root  619 Feb 15 14:03 CentOS-Base.repo
-rw-r--r-- 1 root root  701 Feb 15 14:03 CentOS-centosplus.repo
-rw-r--r-- 1 root root 1329 Feb 15 14:03 CentOS-CR.repo
-rw-r--r-- 1 root root  668 Feb 15 14:03 CentOS-Debuginfo.repo
-rw-r--r-- 1 root root  227 Feb 15 14:03 CentOS-epel.repo
-rw-r--r-- 1 root root  663 Feb 15 14:03 CentOS-Extras.repo
-rw-r--r-- 1 root root  242 Feb 15 14:03 CentOS-fasttrack.repo
-rw-r--r-- 1 root root  928 Feb 15 14:03 CentOS-Media.repo
-rw-r--r-- 1 root root  639 Feb 15 14:03 CentOS-PowerTools.repo
-rw-r--r-- 1 root root 1382 Feb 15 14:03 CentOS-Sources.repo
-rw-r--r-- 1 root root   74 Feb 15 14:03 CentOS-Vault.repo

清空yum源配置文件（注意目录地址）

[root@iZ2ze1e3u7m7oe426pyndaa yum.repos.d]# rm -rf *

下载新的阿里云镜像源

[root@iZ2ze1e3u7m7oe426pyndaa yum.repos.d]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
--2022-02-15 14:04:11--  https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
Resolving mirrors.aliyun.com (mirrors.aliyun.com)... 39.96.118.189, 39.96.118.196, 39.96.118.148, ...
Connecting to mirrors.aliyun.com (mirrors.aliyun.com)|39.96.118.189|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2495 (2.4K) [application/octet-stream]
Saving to: ‘/etc/yum.repos.d/CentOS-Base.repo’

/etc/yum.repos.d/CentOS-Base.repo                  100%[================================================================================================================>]   2.44K  --.-KB/s    in 0s      

2022-02-15 14:04:11 (63.2 MB/s) - ‘/etc/yum.repos.d/CentOS-Base.repo’ saved [2495/2495]

生成缓存

[root@iZ2ze1e3u7m7oe426pyndaa yum.repos.d]# yum makecache
CentOS-8.5.2111 - Base - mirrors.aliyun.com                                                                                                                                  25 MB/s | 4.6 MB     00:00    
CentOS-8.5.2111 - Extras - mirrors.aliyun.com                                                                                                                               296 kB/s |  10 kB     00:00    
CentOS-8.5.2111 - AppStream - mirrors.aliyun.com                                                                                                                             46 MB/s | 8.4 MB     00:00    
Metadata cache created.
[root@iZ2ze1e3u7m7oe426pyndaa yum.repos.d]# ll
total 4
-rw-r--r-- 1 root root 2495 Feb 14 21:16 CentOS-Base.repo