299 lines
5.4 KiB
Markdown
Executable File
299 lines
5.4 KiB
Markdown
Executable File
---
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title: Linux 系统管理指南
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tags:
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- Linux
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- Shell
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- Bash
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- 系统管理
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- Ubuntu
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created: 2026-04-21
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---
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# Linux 系统管理指南
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## 基础命令
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### 文件与目录
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```bash
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# 目录操作
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ls -la # 列出所有文件（含隐藏）
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cd /path # 切换目录
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pwd # 显示当前目录
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mkdir -p a/b/c # 递归创建目录
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rm -rf directory # 强制删除目录
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# 文件操作
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cp file1 file2 # 复制
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mv file1 file2 # 移动/重命名
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rm file # 删除
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touch file # 创建空文件
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# 查看文件
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cat file # 全文显示
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head -n 20 file # 前20行
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tail -n 50 file # 后50行
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tail -f log # 实时跟踪日志
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less file # 分页查看
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# 搜索
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grep "pattern" file
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find / -name "*.log"
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locate filename
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```
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### 用户与权限
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```bash
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# 用户管理
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sudo useradd -m -s /bin/bash username
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sudo passwd username
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sudo usermod -aG sudo username
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sudo deluser username
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# 权限
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chmod 755 file # 数字形式
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chmod +x script.sh # 添加执行权限
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chown user:group file # 修改所有者
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# 权限数字
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# 4 = r, 2 = w, 1 = x
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# 755 = rwxr-xr-x (所有者全部, 其他读+执行)
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# 644 = rw-r--r--
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# 600 = rw-------
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```
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### 进程管理
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```bash
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# 查看进程
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ps aux | grep nginx
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top # 实时监控（退出按 q）
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htop # 更友好的 top（需安装）
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# 管理进程
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kill PID # 温柔终止
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kill -9 PID # 强制终止
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killall nginx # 按名字终止
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# 后台运行
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nohup command & # 忽略挂断信号后台运行
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command & # 后台运行
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jobs # 查看后台任务
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fg %1 # 调到前台
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```
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## 软件安装
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### APT（Debian/Ubuntu）
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```bash
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# 更新源
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sudo apt update
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sudo apt upgrade
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# 安装软件
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sudo apt install nginx
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sudo apt install docker.io
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# 搜索
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apt search nginx
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# 卸载
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sudo apt remove nginx
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sudo apt autoremove
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```
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### YUM/DNF（CentOS/RHEL）
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```bash
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sudo dnf install nginx
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sudo dnf update
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sudo dnf remove nginx
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```
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### 系统服务（systemd）
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```bash
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# 管理服务
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sudo systemctl start nginx
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sudo systemctl stop nginx
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sudo systemctl restart nginx
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sudo systemctl status nginx
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sudo systemctl enable nginx # 开机自启
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sudo systemctl disable nginx # 禁用开机自启
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# 查看服务
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systemctl list-units --type=service --state=running
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```
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## 网络命令
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```bash
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# 查看网络
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ip addr show
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ip link set eth0 up/down
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ss -tuln # 查看监听端口
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netstat -tuln
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# 网络测试
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ping -c 4 google.com
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curl -I https://example.com
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wget https://example.com/file
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# 端口转发
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sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 3000
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# 防火墙
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sudo ufw allow 22 # 开放SSH
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sudo ufw allow 80/tcp # 开放HTTP
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sudo ufw allow 443/tcp # 开放HTTPS
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sudo ufw enable
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sudo ufw status
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```
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## 磁盘管理
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```bash
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# 查看磁盘使用
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df -h
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du -sh /var/log/*
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# 挂载
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sudo mount /dev/sdb1 /mnt/usb
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sudo umount /mnt/usb
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# 分区
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sudo fdisk /dev/sdb
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# 或使用 parted
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# 创建文件系统
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sudo mkfs.ext4 /dev/sdb1
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sudo mkfs.xfs /dev/sdb1
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```
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## Shell 脚本
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```bash
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#!/bin/bash
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# 变量
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NAME="World"
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echo "Hello, $NAME!"
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echo "当前目录: $(pwd)"
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# 条件
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if [ -f "file.txt" ]; then
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echo "文件存在"
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elif [ $age -ge 18 ]; then
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echo "成年"
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else
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echo "未成年"
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fi
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# 循环
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for file in *.txt; do
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echo "处理: $file"
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done
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# 函数
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function greet() {
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echo "Hello, $1!"
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}
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greet "张三"
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# 常用判断
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# -f file 文件存在
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# -d dir 目录存在
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# -z string 字符串为空
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# -n string 字符串非空
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# -eq, -ne 数字相等/不等
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# -lt, -gt 数字小于/大于
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# 读取输入
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read -p "请输入名称: " name
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echo "你输入了: $name"
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# 函数返回状态
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function check() {
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if [ $1 -gt 10 ]; then
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return 0 # 成功
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else
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return 1 # 失败
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fi
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}
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```
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## 日志查看
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```bash
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# 系统日志
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journalctl -u nginx # 查看nginx服务日志
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journalctl -f # 实时跟踪
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journalctl --since "1 hour ago"
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# 应用日志
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tail -f /var/log/nginx/access.log
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tail -f /var/log/syslog
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# 历史命令
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history | grep apt
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```
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## 常用配置
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### SSH
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```bash
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# 生成密钥
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ssh-keygen -t ed25519 -C "your_email@example.com"
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# 复制公钥到服务器
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ssh-copy-id user@hostname
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# SSH 配置 (~/.ssh/config)
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Host myserver
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HostName 192.168.1.100
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User ubuntu
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Port 22
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IdentityFile ~/.ssh/id_ed25519
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```
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### Crontab 定时任务
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```bash
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# 编辑 crontab
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crontab -e
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# 格式: 分 时 日 月 周 命令
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# 示例:
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# 0 9 * * 1-5 # 每周一到周五9点
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# */15 * * * * # 每15分钟
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# 0 2 * * * # 每天凌晨2点
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# @reboot # 开机运行
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```
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## Docker（Linux）
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```bash
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# 安装 Docker
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curl -fsSL https://get.docker.com | sudo sh
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sudo usermod -aG docker $USER
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# Docker Compose
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sudo curl -L "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" \
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-o /usr/local/bin/docker-compose
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sudo chmod +x /usr/local/bin/docker-compose
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```
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## 故障排查
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| 问题 | 命令 |
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| 端口占用 | `lsof -i :8080` 或 `ss -tulpn \| grep 8080` |
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| 磁盘满 | `df -h` + `du -sh /*` |
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| 内存满 | `free -h` + `top` |
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| CPU 高 | `top` 或 `htop` |
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| 服务起不来 | `systemctl status xxx` + `journalctl -u xxx` |
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| 网络不通 | `ping 8.8.8.8` + `curl -I url` |
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