To get the full benefits and support of the new vSAN 8 Express Storage Architecture (ESA), you will need modern hardware from the official vSAN ESA Ready Node HCL. However, from an education and learning point of view, you may want to explore some of the VSAN ESA workflows and easiest way to do that, well you probably know the answer .... it is using Nested ESXi of course!
With my recently published vSphere and vSAN 8 Lab Deployment Script, you can use that as the base and the Nested ESXi 8.0 IA Virtual Appliance to setup vSAN 8 ESA using virtual hardware 😀
Before you can enable vSAN ESA, each ESXi host within the vSphere Cluster must have a minimum of 16GB of memory. You will see an error as shown in the screenshot above during the pre-check. There are also two other warnings that will show up, one regarding the use of vSphere Lifecycle Manager (vLCM) if the cluster has not been setup and you can safely ignore. The other is a network pre-check to ensure the physical (virtual in our case) network adapter is at least 25GbE or greater. For Nested ESXi, the virtual network adapter will show only 10GbE and you can also ignore and proceed after meeting the memory requirement, which is a hard pre-check.
Note: Thanks to reader Alaa, it looks like the 16GB memory minimum is only for a single disk to be used with vSAN ESA. If you wish to add a second disk, the memory needs to be updated to at least 18GB and potentially for if you plan to add additional disks. vSAN ESA officially requires 512GB of memory for a supported configuration and while that is going to be overkill for Nested environment, you may need to play with memory if you are running into enablement issues, especially if you plan to add additional disks.
During the disk claiming part of the wizard, you will see more warnings and this is expected because we are not using "hardware" from vSAN ESA HCL and hence auto-claim can not be used but we can still select the virtual disks that we wish to use and click next to proceed.
Again, this is purely for educational and learning purposes, especially in familiarizing yourself with the vSAN ESA enablement workflow. Outside of the initial workflow, I am not sure there will be any real benefits of using vSAN ESA in a Nested ESXi environment, especially compared to the vSAN Original Storage Architecture (OSA) which can be enabled with just 8GB of memory per host versus the 16GB required by vSAN ESA.