Linux

Monitoring processes

a. Type top. Notice that the display stays in the window but changes every few seconds. What is the %CPU usage of top? Leave top running, and in a second terminal window launch the command find / -empty (ignore any messages that you receive while it is running). While find executes, look for find in tops display. It moves around. Why is it moving? As it moves, what happens to its %CPU and %MEM values? After perhaps 30 seconds or a minute, find will end. Examine top. What happens to the find entry?

b. Another process listed in top is init with a PID of 1. Why does init have a PID of 1?

c. Start the GUI System Monitor program by selecting Applications -> System Tools ->System Monitor. Click on the Processes tab. Compare this to what you see in top. Compare the fields available in the System Monitor to those available in top. What fields differ (if any)? Close this preferences window. Click on the Resources tab. Compare the information about CPU usage, memory and swap history as shown in the GUI to what top tells you. You can close the system monitor now (leave top running).

d. You interact with top by entering letters which are commands. Type u to change users and when prompted, enter Student. What are the top processes listed for Student?[Attach a screenshot] What is the smallest PID and the largest PID that you see in the top window? Type u and to reset top to showing all users. Type d to change the refresh duration from the default (3 seconds) and type 0.5 . Notice how quickly top changes. You should see the top process change quickly. Type d 3 to reset it. Type q to exit top.