Posted by Brian on Mar 4, 2010 in Featured, Performance, Tools, Troubleshooting, VMware | View Comments
By now everyone should know that esxtop is a great tool that you can use to find out what might be causing performance issues on your ESX host. I don’t plan on writing a post on how to use esxtop. You can refer to Duncan’s ESXtop post for details on thresholds or to VMwares esxtop bible for good base information.
This post is more of a starting point on what ESXplot is and how to install and use. By now most of you should know that ESXplot was born out of the mind of Geoff White of VMware. Geoff is a coworker of Scott Drummonds the well known ESX performance expert. Esxplot is a GUI application that lets you explore the data collected by esxtop in batch mode. The program takes a single command line argument which is the esxtop batch mode output file.
Why would you want to use esxplot? Well in the past your options to examine these files were to use Excel or Perfmon. Both options were very slow, sometimes taking hours to import the file before viewing. With esxplot your dump file will open within seconds usually. For more details you can read Scott’s post on version 1.0.
If you are using Windows to view your files you have 2 options. You can use the Windows binary file or run the python script. If you wish to run the python script you will need the following applications installed.
Python 2.6 or higher but not Python 3.x – Download
wxPython – Download
NumPy is also needed – Download
Once installed the application is very easy to use. First thing to do in capture some data from esxtop in batch mode using the command below. Then copy the file over to your workstation that you will run esxplot on. Open the app and the File ->Import->Dataset option from the menu to view your file. Then from the lower left section that will list your Hosts name open the tree to view all the captured values.
esxtop -b -d 2 -n 100> esxtopcapturefile.csv
You can download esxplot from here.
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Posted by admin on Sep 29, 2009 in Performance, VMware | View Comments
Myself along with many other admins supporting Virtual Infrastructures are always looking to increase their ability to diagnose performance related issues. As new software and hardware technology is released we get more tools to help and more things to think about.
To help with the issue VMware has published a few helpful documents. I have broken down the different documents and included links to the originals at VMware.
Hyper-Threading is a common question about how ESX handles this technology. I’m going to assume that if you are reading this that you know what HT is. Hyper-Threading has been supported in ESX since version 2, since ESX is aware of HT it treats logical cores different than physical cores. Using HT does offload some of the SMP calculations from the OS and allows the processor hardware to do the work at a faster rate. You can read the whole documente here.
The next VMware article covers the ESX Monitor modes available. It breaks down the different Hardware Virtualization options supported for different ESX features, guest OS and processor families. See full article here.
Next in line is Guest OS based performance. Due to the fact that VMware removes the hardware layer from the VMs touch. This in turn makes Windows perfmon or Top in Unix return results that are not very accurate. So this brings up the question are you using your tradition tools that you would install on your physical servers? If so they are unaware of the benefits being realized by the virtualization software. The tools do not have an accurate view of cpu resources since each VM is getting a fraction of CPU time. See the document here.
The next big item to cover is CPU read time. This value always gets a lot of questions and is confusing to many. To make it as clear as I can Ready Time is the amount of time a Virtual Machine waits to run a process but has not be provided CPU resources on which to execute. There are two ways to get a value for ready time, you can use Esxtop or Virtual Center. If you use Esxtop you will get a percentage value and Virtual Center will give you a time value in milliseconds. To give you an idea 1,000 ms in VC’s report is equal to 5% fom esxtop. Read more on full article here.
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