直接升级

sudo dnf update -y
sudo reboot
cat /etc/centos-release
sudo dnf install centos-release-stream -y
sudo dnf swap centos-{linux,stream}-repos -y
sudo dnf distro-sync -y
sudo reboot
cat /etc/centos-release

官方文档：https://www.linode.com/docs/guides/migrate-from-centos-8-to-centos-stream/ (opens new window)

报错处理

如果执行过dnf update，有这种报错：

Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

就先手动更新一下源：

cd /etc/yum.repos.d/
sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*