The first line prints the average values since the last time the computer was rebooted.

The following command will display the data that will update in every 5 seconds and the values will be re-measured and reported every 1 second. The following command will update its report every 5 seconds until there is an interrupt. The vmstat command updates its output like top command. On multiple CPU systems, vmstat averages the number of CPUs into the output. In case the command is never being run, the data will be from the last reboot to the current time. For displaying statistics, the data is collected from the last time the command was run to the present. 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.

Ubuntu get cpu usage