How to write a shell script ?

[sid1881s]

Hi Everyone,

I am from the performance testing background and working on an application hosted on an app server having the Fedora OS. While load testing, I will need to collect the CPU, Memory and Disk metrics for the app server.

With regard to the same, I will need to write a shell script which will generate the output from the vmstat and iostat command at a sampling rate of 5 seconds and redirect to a single notepad.

I tried to google it but did not find any feasible solution. Can someone please help. It's urgent.

Thanks,
Sid

[jpollard]

You likely want the "sar" package - it already does most of this, and more accurately (kernel timers and such, If I remember right).

"sar" is "System Activity Report" and provides daemon services to record a lot of data, and at flexible intervals.

[george_toolan]

Try

while true; do vmstat >> notepad; sleep 5; done

or to get more detailed information

cat /proc/vmstat

[jpollard]

The results of such a script is inaccurate - a sleep of 5 seconds makes an interval of 6 seconds since it takes a time to run vmstat....

Just doing "vmstat 5>log" will do the same thing slightly more accurately.

Sar will record more information more consistently and allow you to post process/select different data over the same time period.