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Quick Tip - What hashing algorithm is supported for ESXi Kickstart password?

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I had a question the other day asking whether the encrypted password which can be specified within an ESXi Kickstart file (denoted by the --isencrypted flag) can use a different hashing algorithm other than MD5? The answer is absolutely yes. In fact, MD5 as a default hashing algorithm has NOT been used for a number of releases, probably dating back to classic ESX (you know, the version that had the Service Console).

For all recent releases of ESXi including 5.5 to 6.7, the default hashing algorithm has been SHA512 for quite some time now. Below are two ways in which you can check which default hashing algorithm is currently being used:

Option 1 - SSH to ESXi host and take a look at /etc/pam.d/passwd


Option 2 - SSH to ESXi host and take a look at /etc/shadow and look at the field prior to the salt.

As a reference:

  • $1$ - MD5
  • $5$ - SHA256
  • $6$ - SHA512

Leveraging Instant Clone in vSphere 6.7 for extremely fast Nested ESXi provisioning

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The idea of "Instant Cloning" a Nested ESXi VM (running ESXi in a VM) is not a new concept. In fact, I had shared a solution back in 2015 using the private VMFork APIs. However, what has changed is the ease of consumption, primarily due to the re-architecture of Instant Clone in vSphere 6.7 (more details here and here) which resulted in a public and simplified API. Some of you might ask, why not simply clone a Nested ESXi VM or create a Link Clone? What benefit would I get by using Instant Clone?

The answer is not only speed, but the fact that the instantiated VM is fully operational and ready to start executing where as a traditional full clone or linked clone requires a full OS boot up that can take up to several minutes to deploy and configure. This may not sound like much for a small number of Nested ESXi VMs, but as you increase the number of instances, Instant Clone really shines while still maintaining speed and the instant availability of the VM. As you can imagine, this definitely opens up for some interesting use cases whether it be for personal home lab or educational purposes like VMware HOL. In addition, we also have customers who deploy Nested ESXi not only at high scale but also with a high churn rate for development purposes, think CI/CD type of a workload who can also benefit from Instant Clone.

So how fast are we talking about? Lets say you wanted to test out the latest version of VSAN in vSphere 6.7, you would normally deploy 3 Nested ESXi VMs, power them up and wait for them to be ready on the network. With Instant Clone, you can deploy three fully functional Nested ESXi VMs in just 30seconds! As the VMs are instantly available for consumption, you can start the VSAN enablement workflow immediately and even parts of that can be baked into the Instant Clone workflow. With the ease of provisioning Nested ESXi VMs, you can simply maintain a catalog of ESXi templates which are in "frozen" states and then leverage Instant Clone to deploy just-in-time Nested ESXi environments and discard them once you are done. Pretty slick if you ask me! and something I plan on using going forward.

Disclaimer: Nested ESXi is still not officially supported by VMware. Please use at your own risk.

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vYetti - Fun animated vSphere Login UI customization

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For those that have been asking about how to customize the vSphere Client Login UI to include this fun little animated login screen as shown below, you can find the complete instructions on my github repo: https://github.com/lamw/vyetti-vsphere-client-customization

I wanted to take a moment and give thanks and credit to the original author (Darin S) who created the animated login, which he referred to as an "Animated SVG Avatar". I remember seeing this on my Twitter stream a few months back where it was shared on codepen.io, which is a platform for web developers to easily show off their demos. From what I could gather, the original demo had used MorphSVGPlugin.min.js which is a Javascript library that provided the animation. Apparently, the use of this library required a membership which prevented anyone from consuming this outside of codepen.io for demo purposes. While searching online, I accidentally stumbled across another similiar project by Balram Chavan who developed an alternative solution simply using Angular 5. With Balram's solution, I was able to make the necessary minor modifications (thanks to Jeeyun from the Clairty team on helping me with some of my Anuglar questions) to get this fully incorporated into the vSphere Client UI. I am sure there are other improvements that can be made to the customization such as a more "clarity" look/feel as the old the old "blue marge" theme background is pretty dated but I will leave that to someone more creative than me 🙂