我在多个 Proxmox Hypervisor 上运行多个 Ubuntu 20.04 服务器。
1 台服务器刚刚遇到了 apt 更新问题，但其他服务器都正常。Ubuntu 服务器版本都是相同的 (20.04.2)，并且都只运行 CLI。
所有服务器 /etc/apt/sources.list 都是相同的 我在 1 个服务器上看到的错误是
Err:1 http://security.ubuntu.com/ubuntu focal-security InRelease
400 Bad Request [IP: 91.189.91.39 80]
Err:2 http://ubuntu.mirror.serversaustralia.com.au/ubuntu focal InRelease
400 Bad Request [IP: 27.50.85.5 80]
Reading package lists...
E: The repository 'http://security.ubuntu.com/ubuntu focal-security InRelease' is not signed.
E: Failed to fetch http://security.ubuntu.com/ubuntu/dists/focal-security/InRelease 400 Bad Request [IP: 91.189.91.39 80]
E: The repository 'http://ubuntu.mirror.serversaustralia.com.au/ubuntu focal InRelease' is not signed.
E: Failed to fetch http://ubuntu.mirror.serversaustralia.com.au/ubuntu/dists/focal/InRelease 400 Bad Request …