更换国内yum源:

更换国内yum源，推荐阿里云yum或者腾讯yum。

• 阿里yum源： https://developer.aliyun.com/mirror/centos
• 腾云yum源： https://mirrors.tencent.com/help/centos.html

[root@VM-16-9-centos ~]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup.3
[root@VM-16-9-centos ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.cloud.tencent.com/repo/centos8_base.repo
--2022-03-18 15:52:41--  http://mirrors.cloud.tencent.com/repo/centos8_base.repo
Resolving mirrors.cloud.tencent.com (mirrors.cloud.tencent.com)... 182.254.90.210, 121.51.52.30, 121.51.82.61, ...
Connecting to mirrors.cloud.tencent.com (mirrors.cloud.tencent.com)|182.254.90.210|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1792 (1.8K) [application/octet-stream]
Saving to: ‘/etc/yum.repos.d/CentOS-Base.repo’

/etc/yum.repos.d/CentOS-Base.re 100%[====================================================>]   1.75K  --.-KB/s    in 0.007s  

2022-03-18 15:52:41 (264 KB/s) - ‘/etc/yum.repos.d/CentOS-Base.repo’ saved [1792/1792]

清理之前的yum缓存

yum clean all

建立新的缓存

yum makecache