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Sovrab Roy
Sovrab Roy

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Useful Linux Commands Every System Administrator Should Know

#bash #security #linux #devops

Useful Linux Commands Every System Administrator Should Know

Linux system administration becomes much easier when you know the right commands for monitoring, troubleshooting, and managing servers efficiently.

In this article, I’ll share some useful Linux commands that I regularly use while managing production servers and cloud infrastructure environments.

1. Check System Uptime 

uptime
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Displays:

  • server uptime
  • current load average
  • active users

Useful for quick server health checks.

2. Monitor Running Processes 

htop
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or

top
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Helps identify:

  • high CPU usage
  • memory consumption
  • overloaded processes

3. Check Disk Usage 

df -h
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Displays disk space usage in human-readable format.

4. Analyze Directory Sizes 

du -sh *
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Very useful when troubleshooting storage problems.

5. Check Memory Usage 

free -m
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Shows:

  • RAM usage
  • swap usage
  • available memory

6. View Running Services 

systemctl list-units --type=service
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Manage services:

sudo systemctl restart nginx
sudo systemctl status mysql
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7. Monitor Network Connections 

ss -tulpn
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Useful for checking:

  • open ports
  • active services
  • listening processes

8. Search Logs Efficiently 

tail -f /var/log/syslog
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or

journalctl -xe
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Essential for troubleshooting server issues.

9. Secure File Permissions 

chmod 644 file.txt
chmod 755 script.sh
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Understanding Linux permissions is critical for server security.

10. Check Server IP Address 

ip a
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or

hostname -I
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11. Test Server Connectivity 

ping google.com
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Check routing:

traceroute google.com
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12. Monitor Real-Time Resource Usage 

vmstat 1
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Provides live system performance statistics.

13. Docker Management Commands

List containers:

docker ps
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View logs:

docker logs container_name
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Restart container:

docker restart container_name
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14. Secure SSH Access

Restart SSH:

sudo systemctl restart ssh
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Check SSH port:

sudo ss -tulpn | grep ssh
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Conclusion

Linux commands are powerful tools for server administration, monitoring, troubleshooting, and infrastructure management.

A strong understanding of Linux fundamentals helps system administrators maintain stable, secure, and high-performance production environments.

I regularly work with Linux servers, Docker, cPanel/WHM, hosting technologies, and cloud infrastructure optimization.

🌐 Portfolio:
https://sovrabroy.online

linux #devops #bash #serveradministration

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