系統 - CentOS - 解決Failed to download metadata for repo appstream問題

參考資訊：
https://techglimpse.com/failed-metadata-repo-appstream-centos-8/

問題如下：

Failed to set locale, defaulting to C.UTF-8
CentOS Linux 8 - AppStream
Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

解法如下：

# 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-*
# yum update -y