Hello World

今天想在 Linode 的一台 CentOS 8 虛擬機安裝套件
但出現以下的錯誤訊息

[root@helloworld yum.repos.d]# yum upgrade
CentOS-8 - AppStream                                                                                                                                                                                         984  B/s | 280  B     00:00
Failed to download metadata for repo 'AppStream'
Error: Failed to download metadata for repo 'AppStream'

或是以下的錯誤訊息
[root@test yum.repos.d]# yum upgrade
CentOS Linux 8 - AppStream                      533  B/s | 280  B     00:00
Errors during downloading metadata for repository 'appstream':
  - Status code: 404 for http://mirrors.linode.com/centos/8/AppStream/x86_64/os/repodata/repomd.xml (IP: 2600:3c01:1::607e:6379)
Error: Failed to download metadata for repo 'appstream': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried

發現因為 http://mirrors.linode.com/centos/8/ 下面的檔案都不見了

解決方式:
編輯 CentOS-AppStream.repo 及 CentOS-Base.repo
vi /etc/yum.repos.d/CentOS-AppStream.repo
#baseurl=http://mirrors.linode.com/$contentdir/$releasever/AppStream/$basearch/os/
baseurl=http://mirrors.linode.com/$contentdir/$releasever-stream/AppStream/$basearch/os/

vi /etc/yum.repos.d/CentOS-Base.repo
#baseurl=http://mirrors.linode.com/$contentdir/$releasever/BaseOS/$basearch/os/
baseurl=http://mirrors.linode.com/$contentdir/$releasever-stream/BaseOS/$basearch/os/

雖然不知道會不會爆炸
但只能先醬子了
 

更新: 重開機測試，果然爆炸了 XD




解決方式: 修改 grub2 kernel 預設開機順序

[root@helloworld ~]# grub2-set-default 1
[root@helloworld ~]# grub2-editenv list
saved_entry=1
kernelopts=root=/dev/sda ro console=ttyS0,19200n8 net.ifnames=0 crashkernel=auto rhgb