今天通过博客园首页链接购买了37块钱的天翼云，发现 Debian 最新版本只到11，那么就来升级一下吧。
1、更新当前系统apt updateapt full-upgrade，更新完后发现有一个包没有被升级0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.，执行apt list --upgradable -a看了一下，输出如下：
root@vm:~# apt list --upgradable -a
Listing... Done
base-files/oldstable 11.1+deb11u11 amd64 [upgradable from: 11.1+deb11u1]
base-files/now 11.1+deb11u1 amd64 [installed,upgradable to: 11.1+deb11u11]应该是一个涉及核心系统的包，手动升级一下吧: apt-get install base-files。
2、更新完成后，更换 Debian12 的源，首先备份当前源 mv /etc/apt/sources.list /etc/apt/sources.list.old，然后写入 Debian12 的源，这里用的是清华的源：
cat > /etc/apt/sources.list << EOF
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm main contrib non-free non-free-firmware
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm main contrib non-free non-free-firmware
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm-updates main contrib non-free non-free-firmware
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm-updates main contrib non-free non-free-firmware
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm-backports main contrib non-free non-free-firmware
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm-backports main contrib non-free non-free-firmware
deb https://mirrors.tuna.tsinghua.edu.cn/debian-security bookworm-security main contrib non-free non-free-firmware
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian-security bookworm-security main contrib non-free non-free-firmware
EOF3、继续更新系统apt updateapt full-upgrade，期间会有一些提示信息，根据需要选择。
更新完后，查看系统版本cat /etc/debian_version， 我这里显示的是12.7，嗯，最新版本 Debian 已经更新好了。
Debian 大版本升级还是一如既往的丝滑，从来没有让我失望过👍💖。