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Sovrab Roy
Sovrab Roy

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Advanced Linux Commands That Separate Senior Engineers From Beginners

#bash #linux #devops #sre

🚀 Advanced Linux Commands That Separate Senior Engineers From Beginners

Most people know ls, cd, and grep.

But real-world production troubleshooting needs a different level of Linux knowledge.

Here are some advanced commands every serious DevOps/SRE/Linux engineer should know 👇

1️⃣ Trace system calls of a running process 

strace -p <PID>
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Helps debug:

  • Hung processes
  • File access issues
  • Permission problems
  • Network/system call failures

2️⃣ See which process is secretly eating disk space 

lsof | grep deleted
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Sometimes deleted log files still consume GBs of space because processes keep them open.

3️⃣ Real-time bandwidth monitoring 

iftop
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Perfect for:

  • Detecting traffic spikes
  • Suspicious outbound traffic
  • Network bottlenecks

4️⃣ Trace packet flow like a network engineer 

tcpdump -i eth0 port 443
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Production debugging becomes much easier when you can actually see packets.

5️⃣ Find why a mount point won’t unmount 

fuser -vm /mnt/data
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Shows which processes are using the filesystem.

6️⃣ Debug DNS resolution path 

dig +trace example.com
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Extremely useful during DNS propagation or routing issues.

7️⃣ Watch filesystem changes live 

inotifywait -m /var/www/html
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Great for:

  • Security monitoring
  • Deployment debugging
  • File tracking

8️⃣ Investigate open network sockets 

ss -tulnp
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Modern replacement for netstat.

9️⃣ Find top resource-consuming processes instantly 

ps aux --sort=-%mem | head
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CPU heavy processes:

ps aux --sort=-%cpu | head
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🔟 Analyze disk usage properly 

du -xh / | sort -rh | head -20
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One of the fastest ways to identify storage problems.

1️⃣1️⃣ Monitor logs in real time with systemd 

journalctl -fu nginx
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1️⃣2️⃣ SSH tunneling for secure internal access 

ssh -L 8080:localhost:80 user@server
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Access internal services securely without exposing ports publicly.

1️⃣3️⃣ Find all failed SSH login attempts 

grep "Failed password" /var/log/auth.log
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1️⃣4️⃣ Generate load for testing 

stress --cpu 8 --vm 2 --timeout 60
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1️⃣5️⃣ See process tree hierarchy 

pstree -p
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💡 Senior engineers are not the ones who memorize the most commands.

They are the ones who know exactly what to run during production chaos.

linux #devops #sre #sysadmin #cloud #bash #kubernetes #opensource #networking

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