🔧 Troubleshoot Guide / 故障排查手册

Quick diagnostics for common server issues. SSH connection, Nginx 502, Docker problems, disk full, firewall lockout. 常见服务器问题快速诊断。SSH连接、Nginx报错、Docker问题、磁盘满、防火墙锁死。

SSH Issues / SSH问题

Can't connect / 连不上

# Check if server is online / 检查是否在线
ping -c 3 your-server

# Check port / 检查端口
nc -zv your-server 2222

# Check SSH service / 检查SSH服务
systemctl status sshd
tail -50 /var/log/auth.log | grep ssh

Connection slow / 连接慢

sed -i 's/#UseDNS yes/UseDNS no/' /etc/ssh/sshd_config
sed -i 's/#GSSAPIAuthentication yes/GSSAPIAuthentication no/' /etc/ssh/sshd_config
systemctl restart sshd

Nginx Issues / Nginx问题

502 Bad Gateway

# 1. Check backend / 检查后端服务
systemctl status your-app
ss -tlnp | grep 3000

# 2. Check nginx errors / 检查Nginx错误
tail -50 /var/log/nginx/error.log

# 3. Check config / 检查配置
nginx -t

SSL Expired / 证书过期

# Check expiry / 查过期时间
openssl s_client -connect domain.com:443 -servername domain.com 2>/dev/null | openssl x509 -noout -dates

# Renew / 续签
certbot renew

Docker Issues / Docker问题

Logs filling disk / 日志爆满

cat > /etc/docker/daemon.json << 'EOF'
{"log-driver": "json-file", "log-opts": {"max-size": "10m", "max-file": "3"}}
EOF
systemctl restart docker

Disk cleanup / 磁盘清理

docker system df          # Check usage / 查看占用
docker system prune -af   # Clean all / 全部清理

Common Fixes / 通用修复

📞 Contact / 联系方式

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