歌声与微笑

1、备份原有yum源配置
cd /etc/yum.repos.d/  
mkdir bak
mv ./* bak/

2、下载新的CentOS-Base.repo 到 /etc/yum.repos.d/
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo

3、生成缓存
yum clean all && yum makecache


如果要更新为rocky linux版本，则：
4、安装rocky linux
rpm -i --force  http://mirror.nju.edu.cn/rocky/8.6/BaseOS/x86_64/os/Packages/r/rocky-release-8.6-4.el8.noarch.rpm \
http://mirror.nju.edu.cn/rocky/8.6/BaseOS/x86_64/os/Packages/r/rocky-repos-8.6-4.el8.noarch.rpm \
http://mirror.nju.edu.cn/rocky/8.6/BaseOS/x86_64/os/Packages/r/rocky-gpg-keys-8.6-4.el8.noarch.rpm

5、删除centos残留repo
rm CentOS-Base.repo -f

6、安装
dnf install  epel-release

7、更新系统
dnf update

8、重启
init 6