Using the top utility is pretty awesome. I’ve used top for years on *nix boxes, both at home and on the job to monitor and troubleshoot system performance and issues.
What’s really cool, is that ESXi has it’s own version of top installed called “esxtop”. Here’s a link to the official doc on how to use the esxtop utility: https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.monitoring.doc/GUID-D89E8267-C74A-496F-B58E-19672CAB5A53.html
So…as stated above, ESXi hosts have a version of top called “esxtop”…login to an ESXi host as root, type “esxtop” and and check it out:
From the main interactive screen output above, you can see lots of system information. At the very top, you’ll be able to see uptime, worlds, VM’s CPU count, and mem overcommit, plus more.
Starting on the left column with (process) ID. Name is of course very helpful in knowing the name of the running process (of course lol), then we get into %USED, % RUN…etc. all other columns to the right will give lots of information on each process.
If interactive command help is needed, press “h” for the menu:
In my past experience, most of the time I used esxtop (or top) and sorted and/or isolated columns. In esxtop, use the following keys (shift-[letter]) to sort by column:
This is very helpful in finding the CPU top talkers, and for listing out PID’s numerically in case you need to kill a process.
The other commands are switch commands that can be used along with the sort function to isolate or switch views to isolate those specific components:
For example, I want to see RAM/memory usage by PID, and sort by used – I’ll hit the “m” key, then “shift-U” to output the below:
Any and all that top utility information can be sorted and isolated, plus there are other commands I haven’t dived into. So as you can see, “esxtop” is a very handy, informative and essential tool for viewing and troubleshooting ESXi systems resources and process. Try it out!
Oh and when you want to quit, simply just click “q” and you’re out.
Be sure to check the next blog post that will cover output esxtop log files to CSV.
Thanks and cheers!