atop - cli for system and process monitoring

overview

The atop command in Linux is used for system and process monitoring. It provides a detailed overview of system performance, including CPU, memory, disk, and network usage. Common usage involves running atop in the terminal to get a real-time view of resource utilization. this can help in diagnosing performance issues and understanding system behavior over time. It can also log this information for historical analysis.

common usage

1. Basic Usage atop - This command will start atop and display real-time system performance metrics.

2. Write log: atop -w /var/log/atop.log 60 This command tells atop to write system performance data to /var/log/atop.log every 60 seconds.

3. Reading from a Log File: atop -r /var/log/atop.log - This command reads the performance data from the specified log file. it allows you to navigate through the recorded data.

4. `atop -m

Interactive Commands

In general:

• lower case keys –> show other information for the active processes
• upper case keys –> influence the sort order of the active process list.

get help in interactive mode

• ? or h: Request for help information.

exit | quit

• q: Quit the program.

Lower Case Commands

• g: Show generic output (default).
• m: Show memory-related output.
• d: Show disk-related output.
• n: Show network-related output.
• s: Show scheduling characteristics.
• v: Show various process characteristics.
• c: Show the command line of the process.
• o: Show the user-defined line of the process.
• u: Show the process activity accumulated per user.
• p: Show the process activity accumulated per program.

sorting

• A: automatically by the most busy system resource.
• C: by CPU consumption (default).
• M: by memory consumption.
• D: by disk accesses issued.
• N: by network packets received/transmitted.

atop vs top

| Feature | atop | top | |————————–|————————————————–|—————————————–| | Purpose | system and process monitoring tool | Real-time system and process monitoring tool | | Detailed Resource Usage | Yes | Basic | | Historical Data Logging | Yes | No | | Overloaded Resource Highlighting | Yes | No | | Cumulative Resource Consumption | Yes | No | | Daemon Mode for Continuous Logging | Yes | No | | Process Information | Detailed (CPU, memory, disk, network) | Basic (PID, user, priority, etc.) | | Sorting by Resource Metrics | Yes | Yes | | Ease of Use | More complex, in-depth analysis | Simpler, quick real-time snapshot |