linux - How can I check the last 5 min overall cpu usage using SAR -

i know example of sar sar -u 1 3 gives statistics next 3 seconds 1 second interval .

however sar keeps on collecting information in background (my cron set collect stats every minute ) . there way can query using sar command tell last 5 mins statistics , average .

right using following below command

interval=5; sar -f /var/log/sysstat/sa22 | tail -n $interval | head -n -1 | awk '{print $4+$6}'| awk  '{s+=$1} end {print s/$interval}'  

to check overall cpu usage in last 5 min .

is there better way ?

unfortunately when using -f option in sar interval , count doesn't return average value given interval (as expect). instead returns first recorded value in sar file

the way work around use -s option allows specify time @ start sampling period. i've provided perl script below finishes call sar constructed in way return you're looking for.

hope helps.

peter rhodes.

#!/usr/bin/perl    $interval = 300;        # seconds.  $epoch    = `date +%s`;  $epoch   -= $interval;  $time     = `date -d \@$epoch +%h:%m:00`;  $dom      = `date +%d`;  chomp($time,$dom);  system("sar -f /var/log/sysstat/sa$dom -b -s $time 300 1");