Dear old ESXTOP aka How to schedule ESXTOP batch mode

Recently I had to record a night activity of a specific VM running on a specific host for troubleshooting reasons because vCenter data wasn’t just enough for that.

Using a number of blog posts around from Duncan Epping and others (it was many, I don’t even have the links anymore) I’ve put up my personal guide about how to take over this task because every time it’s like I have to start from scratch so I decided to document it.

First thing I created a script with the specific run time and collection data I needed:

vi <path>/record-esxtop.sh
esxtop -b -a -d 2 -n 3600 > /esxtopoutput.csv

OR

esxtop -b -a -d 2 -n 3600 | gzip -9c > /esxtopoutput.csv.gz

(-d=sampling rate, -n=number of iterations; the total run time is “d*n” in seconds)
(second version creates a zipped version of the output)

Let’s make this script executable:

chmod +x <path>/record-esxtop.sh

Then, since in latest versions of ESXi there is no crontab, you’ll need to edit the cron file for the user you want to run the script with:

vi /var/spool/cron/crontabs/root

Then add a line similar to this:

30 4 * * * <path>/record-esxtop.sh

Now kill crond and reload:

cat /var/run/crond.pid
ps | grep 
kill -HUP 
ps | grep 
/usr/lib/vmware/busybox/bin/busybox crond
cat /var/run/crond.pid
ps | grep 

Now your script will get executed and you’ll find a file with your data, but how to read it?
It’s dead simple, just open PerfMon on Windows, clear all running counters then right-click on “Performance Monitor” and in the tab “Sources” add your CSV file (need to unpack it first); in the data tab you will then be able to choose metrics and VMs you want to add to your graph.

It would be nice to have a tool that does the same on Mac but I couldn’t find one and I had to use a Windows VM; if you know a Mac alternative for PerfMon please add a comment.

This procedure is supported by VMware as per KB 103346.