Top 30 Linux Monitoring Tools Every Sysadmin Should Know

As the internet industry evolves, countless monitoring tools are available; this article compiles over 80 ways to manage machines, focusing on command‑line, system, log, and infrastructure monitoring.

Eight System Monitoring Tools

1. top

Pre‑installed on many UNIX systems, top displays running processes or threads, sorted by CPU by default.

2. htop

Enhanced version of top, offering easier sorting, a more readable interface, and full interactivity.

3. atop

Similar to top and htop but records daily process logs for later analysis and highlights resources at critical load.

4. apachetop

Monitors Apache web server performance, showing current read/write processes and total request processes.

5. ftptop

Provides basic information about all connections to an FTP server, including session count and active uploads/downloads.

6. mytop

Lightweight tool for monitoring MySQL threads and performance, showing real‑time queries.

7. powertop

Helps diagnose power consumption and power‑management issues, allowing configuration of power settings.

8. iotop

Shows I/O usage with a top -like interface, displaying read/write rates per process and percentage of time spent waiting.

Network‑Related Monitoring Tools

9. ntopng

GUI for network monitoring via a browser, offering host geolocation, traffic visualization, and IP flow analysis.

10. iftop

Monitors traffic on a selected network interface, displaying current usage in a table.

11. jnettop

Visual network traffic monitor, more graphical than iftop, supports custom text output and deep log analysis.

12. bandwidthd

Tracks TCP/IP subnet usage and generates HTML graphs; includes a database for searching and custom reports.

13. EtherApe

Graphical network traffic visualizer that can capture live traffic or read from tcpdump files.

14. ethtool

Displays and modifies network interface parameters, useful for Ethernet diagnostics.

15. NetHogs

Groups network traffic by process rather than by protocol or subnet, helping identify offending processes.

16. iptraf

Collects various metrics such as TCP connection packets/bytes, port statistics, and UDP communication failures.

17. iptstate

Shows how traffic passes through iptables, allowing sorting by user‑defined conditions and state removal.

18. darkstat

Captures network traffic, computes usage statistics, and presents them via a simple HTTP server with a GUI.

19. vnStat

Network traffic monitor that relies on kernel‑provided statistics, using minimal system resources and preserving data across reboots.

20. netstat

Built‑in tool displaying TCP connections, routing tables, and interface statistics.

21. ss

Faster and more detailed alternative to netstat; for a summary use ss -s.

22. nmap

Scans open ports, detects operating systems, and can be used for vulnerability assessment and network discovery.

23. MTR

Combines traceroute and ping into a single network diagnostic tool, repeatedly probing hop latency.

24. tcpdump

Captures packets matching a user‑specified expression, allowing saving for further analysis.

25. Justniffer

TCP packet sniffer that can collect low‑level or high‑level data and generate custom logs, e.g., Apache‑style access logs.