#troubleshooting
All articles tagged #troubleshooting — practical guides from production experience.
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68 posts tagged #troubleshooting · page 6 of 8
How to Check Listening Ports in Linux (2026 Guide)
Check listening ports in Linux with ss, netstat, lsof, and nmap — know which service owns each port, detect unexpected listeners, and troubleshoot connection refused errors.
How to Check Firewall Status in Linux: iptables, firewalld, ufw
Check firewall status in Linux using iptables, firewalld, and ufw — see active rules, verify port access, and diagnose whether firewall is blocking traffic.
Check Disk Usage in Linux: du vs df Explained
Check disk usage in Linux using df and du — understand the difference, read the output correctly, and find what's filling your disk with real command examples.
How to Check CPU Usage in Linux: Real Command Examples
Check CPU usage in Linux using top, mpstat, ps, and vmstat — read per-core breakdown, identify CPU-hungry processes, and diagnose high load in production.
Cannot Connect to Server Linux: Step-by-Step Troubleshooting
Troubleshoot 'cannot connect to server' on Linux — diagnose connection refused, timeout, and network unreachable errors with a systematic step-by-step approach.
top Command Linux: Real-World Guide to CPU and Process Monitoring
Learn how to use the top command on Linux for production troubleshooting — reading CPU, load average, memory metrics, interpreting process states, and diagnosing high CPU and stuck processes in real incidents.
strace Tutorial: Debug Linux Processes Like a Senior Engineer
A practical strace tutorial for production debugging — trace system calls, diagnose hung processes, find missing files, and debug permission errors with real command examples and incident workflows.
ps Command Linux: The Engineer's Troubleshooting Guide
How to use the ps command on Linux to debug high CPU, memory leaks, zombie processes, and unresponsive services — with real production workflows, common mistakes, and a quick-reference cheat sheet.
NGINX Troubleshooting Guide: Complete Production Reference
The complete NGINX troubleshooting reference — 502/504 errors, upstream failures, SSL issues, connection limits, keepalive misconfiguration, and production debugging workflows with real commands.