By default SAR (System Activity Report) captures the server stats every 10 minutes and displays in the output when you run SAR command on any Unix machine having sysstat (/etc/cron.d/sysstat) on it.
To monitor the server stats during some performance test, you would need to have the stats for more close intervals, so that the trend of some server parameter can be analysed and collate with no of vusers or other activities.
To monitor the server stats during some performance test, you would need to have the stats for more close intervals, so that the trend of some server parameter can be analysed and collate with no of vusers or other activities.
To modify the frequency you just need to modify the sysstat file.
Edit the cronjob file:
# vi /etc/cron.d/sysstat
Find:
# Activity reports every 10 minutes everyday
5-55/10 * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1
Modify to:
# Activity reports every 5 minutes everyday
*/5 * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1
Now you can save and exit the file and simply wait 5 minutes for the next run of sysstat to verify that you are collecting data.
Alternately, using WinSCP you can connect to the unix server, navigate to the sysstat file (/etc/cron.d) and edit and save it after modifying the value 10 with the frequency you desire.
PS : you need to have required rights on the server to modify this file.
Also, keep in mind that log size would get increased if you reduce the frequency of stat collection interval.
Also, keep in mind that log size would get increased if you reduce the frequency of stat collection interval.