1.centos8更换为阿里云yum源

2.更换阿里云Yum-centos8源

mv /etc/yum.repos.d/CentOS-Stream-BaseOS.repo /etc/yum.repos.d/CentOS-Stream-BaseOS.repo.backup


curl -o /etc/yum.repos.d/CentOS-Stream-BaseOS.repo https://mirrors.aliyun.com/repo/Centos-8.repo

wget -O /etc/yum.repos.d/CentOS-Stream-BaseOS.repo https://mirrors.aliyun.com/repo/Centos-8.repo

[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# ls
CentOS-Stream-AppStream.repo      CentOS-Stream-Extras.repo            CentOS-Stream-RealTime.repo          epel.repo
CentOS-Stream-BaseOS.repo         CentOS-Stream-HighAvailability.repo  CentOS-Stream-ResilientStorage.repo  epel-testing-modular.repo
CentOS-Stream-BaseOS.repo.backup  CentOS-Stream-Media.repo             CentOS-Stream-Sources.repo           epel-testing.repo
CentOS-Stream-Debuginfo.repo      CentOS-Stream-NFV.repo               epel-modular.repo
CentOS-Stream-Extras-common.repo  CentOS-Stream-PowerTools.repo        epel-playground.repo

3.查询repository列表

4.如果配置后仍然报错 如下

 CentOS Stream 8 - Extras common packages                                                                                        0.0  B/s |   0  B     00:00
Errors during downloading metadata for repository 'extras-common':
  - Curl error (6): Couldn't resolve host name for http://mirrorlist.centos.org/?release=8-stream&arch=x86_64&repo=extras-extras-common [Could not resolve host: mirrorlist.centos.org]
错误：Failed to download metadata for repo 'extras-common': Cannot prepare internal mirrorlist: Curl error (6): Couldn't resolve host name for http://mirrorlist.centos.org/?release=8-stream&arch=x86_64&repo=extras-extras-common [Could not resolve host: mirrorlist.centos.org]
[root@localhost ~]#

5.解决方案之干净利索方案

5.1 备份原有yum仓库整个备份

cp -r /etc/yum.repos.d /home/yum.repos.d.bakcup

5.2.进入原有yum源删除里面所有*.repos文件

cd /etc/yum.repos.d

rm -f *.repo

5.3. 直接覆盖下载阿里云centos-8.0 yum源

wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo

5.4. 更新yum缓存 

yum clean all

yum makecache

OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK