29 - 系统迁移与升级（Debian 11 → 12 → 13）

# 1. 创建 VMware 快照（关机状态更安全）
#    VM → Snapshot → Take Snapshot → 命名为 "pre-upgrade-YYYYMMDD"

# 2. 备份关键目录
mkdir -p /backup/pre-upgrade
tar -czf /backup/pre-upgrade/etc-$(date +%Y%m%d).tar.gz /etc
rsync -aq /var/www/ /backup/pre-upgrade/www/
mysqldump -u root -p --all-databases --single-transaction \
    > /backup/pre-upgrade/all-databases-$(date +%Y%m%d).sql

# 3. 确认当前版本
lsb_release -a
cat /etc/debian_version

# 4. 将当前系统升级到最新 patch
apt update && apt full-upgrade -y && apt autoremove -y

# 5. 检查是否需要重启（内核更新等）
[ -f /var/run/reboot-required ] && echo "需要重启" || echo "无需重启"

# 6. 清理磁盘空间
apt clean
journalctl --vacuum-time=30d
df -h /    # 确认根分区有至少 5 GB 可用空间

# 7. 检查 dpkg 健康状态
dpkg --audit    # 无输出表示正常

# 备份原始 sources.list
cp /etc/apt/sources.list /etc/apt/sources.list.bak-$(date +%F)
cp -r /etc/apt/sources.list.d/ /etc/apt/sources.list.d.bak-$(date +%F)/

# 替换主 sources.list
tee /etc/apt/sources.list << 'EOF'
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm 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 https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm-updates main contrib non-free non-free-firmware
EOF

# 将 sources.list.d 下所有文件中的 bullseye 替换为 bookworm
# 注意：第三方源（如 Docker、NodeSource）需手动确认兼容性
for f in /etc/apt/sources.list.d/*.list; do
    sed -i.bak 's/bullseye/bookworm/g' "$f"
done

# 第一阶段：更新包列表
apt update

# 第二阶段：执行升级（可能需要较长时间，建议在 screen 或 tmux 中运行）
apt full-upgrade -y

# 清理废弃包
apt autoremove -y
apt clean

reboot

# 重启后验证
cat /etc/debian_version    # 应显示 12.x
lsb_release -a
uname -r                   # 确认新内核已加载
systemctl --failed         # 确认无服务启动失败

cp /etc/apt/sources.list /etc/apt/sources.list.bak-$(date +%F)

tee /etc/apt/sources.list << 'EOF'
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ trixie main contrib non-free non-free-firmware
deb https://mirrors.tuna.tsinghua.edu.cn/debian-security trixie-security main contrib non-free non-free-firmware
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ trixie-updates main contrib non-free non-free-firmware
EOF

apt update
apt full-upgrade -y
apt autoremove -y
reboot

# 尝试恢复 dpkg 中断的事务
dpkg --configure -a
apt install -f
apt full-upgrade -y

# 检查失败服务的详细日志
systemctl status <服务名>
journalctl -u <服务名> -xe --no-pager

# 检查 AppArmor 是否阻断
journalctl | grep "apparmor.*DENIED" | tail -20

# 从 live USB 启动，挂载根分区
mount /dev/sda1 /mnt
chroot /mnt

# 将 sources.list 改回 bookworm
vim /etc/apt/sources.list

apt update
apt full-upgrade -y

# 清除已删除包的残留配置文件
dpkg -l | grep '^rc' | awk '{print $2}' | xargs apt purge -y

# 更新 GRUB
update-grub

# 重新加载 systemd 单元（处理单元文件变更）
systemctl daemon-reload

# 最终全系统状态检查
systemctl --failed
df -h
free -h

# 1. 查看具体冲突信息
apt full-upgrade 2>&1 | grep -A5 "has broken"

# 2. 尝试自动修复
apt install -f

# 3. 找出冲突包并单独处理
apt-cache show <package> | grep -E "Depends|Conflicts|Replaces"

# 4. 临时跳过问题包（仅当确认安全时）
apt full-upgrade --ignore-hold

# 5. 查看 dpkg 日志了解历史操作
tail -100 /var/log/dpkg.log