听说丽萨主机的 IP 比较干净，整个了一个新加坡的， apt update 都卡死，竟然使用的是 aliyun：
sudo apt update
Hit:1 http://mirrors.aliyun.com/debian bullseye InRelease
Hit:2 http://mirrors.aliyun.com/debian-security bullseye-security InRelease
Hit:3 http://mirrors.aliyun.com/debian bullseye-updates InRelease
Ign:4 http://mirrors.aliyun.com/debian bullseye-backports InRelease
Err:5 http://mirrors.aliyun.com/debian bullseye-backports Release
404 Not Found [IP: 163.181.201.188 80]
Reading package lists... Done
E: The repository 'http://mirrors.aliyun.com/debian bullseye-backports Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
sudo apt update 0% [Waiting for headers] 0% [Waiting for headers] 0% [Waiting for headers] 0% [Waiting for headers] 0% [Waiting for headers] 0% [Waiting for headers]^C
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