The vmstat command will display statistics about system processes, memory, swap, I/O, and CPU performance. The following command will display extended statistics (-x), the number of times (-t) each report should be displayed for CPU utilization (-c).

The following command will break the CPU utilization into user processes, system processes, I/O wait and idle time. To list the individual report use -c, -d and -h switch for CPU utilization, device utilization and network file system utilization. Running the following command without any options displays all three reports. This utility display system’s average CPU utilization since the last reboot. The iostat command list CPU utilization, device utilization and network file system utilization. 'U' to view processes owned by a specific user.'S' to sort by how long the processes have been running type.'I' to remove the idle processes from the display and to revert back press 'I' again.To modify the output of top command, press: Type 'top' from the terminal to view the statistical data related to the performance of a system. By default, the top command updates data every 5 seconds. The top command displays a real-time view of performance-related data of all running processes in a system. # where the input file has the columns ` ` usage-plot.gp top.dat top.png: #!/usr/bin/env gnuplot -persist -c While true do top -p $PID -bMn 1 | egrep '^+' | awk -v now=$(date +%s) '' > top.dat done unix time - memory with m/g suffix - CPU load in % Run this script (perhaps via nohup) to capture the data: #!/bin/sh If you want to monitor the memory and CPU usage of a particular Linux process for a few minutes, perhaps during a performance test, you can capture the data with top and plot them with gnuplot. Keep reading to learn how.

Linux monitor cpu usage