ESXi Performance Testing with ESXTOP

Yesterday, I worked for one of my clients about testing ESXi host workload performance such as installed VMs, CPU, memory reservation. And I decided that I should write something on it.

VMware ESXi

ESXi is a bare-metal hypervisor that runs directly on server hardware and do not requires the installation of additional underlying operating system. This virtualization software creates and runs its own kernel, which is run after a Linux kernel bootstraps the hardware. It has three interfaces.

  • Hardware
  • Guest system
  • Console Operating System (service console)

ESXi is responsible for allocating all physical resources to installed VMs without knowing that how much VMs are installed and how much they are using resources in the form of memory, CPU, network etc.

Installation of ESXi host

ESXi host can be installed on any supported hardware as well as a virtual machine using VMware Workstation. For the lab setup, I’ve installed ESXi 6.0 host inside VMware Workstation with following resources

Serial No. Component Requirements
1. Memory 8 GB
2. Processor 2 vCPU
3. HDD 80 GB


To start the installation process in VMware Workstation, Attach the ESXi 6.0 iso image to the virtual machine and boot the system. You will be presented the standard ESXi 6.0 Boot Menu as shown below. Press “Enter” to continue, and follow the step-by-step process to complete installation.

When the installation process completed, reboot the server.

Configure its IP address and host name by pressing F2 after reboot. And after initial settings, test the network connectivity.

Performance Testing of ESXi host

To test the performance of an ESXi host in the form of memory, CPU, and network utilization, ESXTOP tool is used. It is a very good tool available for VMware administrators to troubleshoot the performance issues.

Before configuring ESXTOP, you’ll need to install vSphere Client and follow the step by step process to complete the setup. After vSphere Client installed, connect your ESXi host using vClient. Enter root user and password, and click Login.

Press F2 to enter the changes, then, go to Troubleshooting Options and enable SSH.

Then, to configure putty, open putty interface, enter your ESXi host IP address, Port 22, and click Open button. Then, login with your ESXi host’s root user and password.

On Putty interface, type esxtop, and it will look like this.

To test the performance CPU, memory, network parameters are measured.

CPU Performance Testing

For CPU performance testing, %USED, %RDY, %CSTP values are used.

Type c on putty’s window, and it will show some results like the following figure.

Memory Performance Testing

For memory performance, type m, and it will show following results.

Network Performance Testing

For network performance testing type n, and it will look like this:

Disk Device Performance Testing

For disk device performance testing, type u and it will show the results like this:


VisualEsxtop is another nice tool introduce as a VMware Fling on 1st July, 2013 to test ESXi performance graphically. It directly connects you to ESXi host or vCenter Server. As per VMware Labs

VisualEsxtop is an enhanced version of resxtop and esxtop. VisualEsxtop can connect to VMware vCenter Server or ESX hosts, and display ESX server stats with a better user interface and more advanced features.”

I hope you have enjoyed reading this post. Thanks for reading! Be social and share it to social media if you feel worth sharing it.


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