The Resource Monitoring Vector
When an Ubuntu Linux server experiences a sudden, inexplicable spike in CPU usage or runs out of RAM, the administrator must immediately identify the specific application responsible. Without a graphical interface, you cannot rely on tools like the Windows Task Manager. You require a command-line utility capable of displaying a live, dynamically updating list of every active process, sorted by exact resource consumption.
How to View Running Processes
The universal, built-in tool for process monitoring on Linux is the top command.
1. Open your terminal application or connect to your server via SSH.
2. To launch the live monitoring interface, execute the following command:
top
3. The terminal will instantly transform into a dashboard. The top half displays overall system health (total CPU load, remaining RAM, and Swap usage).
4. The bottom half displays a live, scrolling list of individual processes. By default, this list is automatically sorted by the %CPU column (the most demanding applications are forced to the top).
5. To sort the list by Memory consumption instead, press Shift + M on your keyboard while the dashboard is running.
6. To cleanly exit the dashboard and return to your standard command prompt, simply press the Q key.
If you require a more colourful, interactive, and user-friendly interface, you can install its modern successor by executing sudo apt install htop, and then launching it by typing htop.