How to collect CPU usage on Linux using Shell script

Following script will help to collect CPU based on on every SAMPLE_TIME. This will help to collect IDLE CPU our from “vmstat” and store them in a file.

#Setup SAMPLE_TIME for cpu data collection interval
SAMPLE_TIME=5
while true
do
x=`vmstat | grep -v procs | grep -v swpd | awk '{print $15}'`
echo `date +"%m-%d-%y %T"` $x
sleep ${SAMPLE_TIME}
done

Create file with above contents and save it as test_cpu.sh for example. 

Now, to run this collection in background use the following command.

nohup ./test_cpu.sh 1>test_cpu.out 2>&1 &

you can monitor using “tail -f test_cpu.out” for incremental progress of data collection. You can also use any visual tool like power BI or Excel for quick analysis.