Centos8.4.2105升级源

[root@ns518 wp-content]# yum update
CentOS Linux 8 - AppStream                                             197  B/s |  38  B     00:00    
Error: Failed to download metadata for repo \'appstream\': Cannot prepare internal mirrorlist: No URLs in mirrorlist

KS安装的centos,

yum -y install python 失败。update也不行，替换阿里/163/腾讯云的源都不行，于是如下操作解决：

https://serverfault.com/questions/1093922/failing-to-run-yum-update-in-centos-8

sed -i \'s|baseurl=http://vault.centos.org|baseurl=http://vault.epel.cloud|g\' /etc/yum.repos.d/CentOS-Linux-*

https://haydenjames.io/fix-error-failed-to-download-metadata-for-repo-appstream-centos-8/

dnf –disablerepo ‘*’ –enablerepo=extras swap centos-linux-repos centos-stream-repos

dnf distro-sync