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Failed to locate kickstart on Nested ESXi VM CD-ROM in VCF 9.0

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If you are automating the installation of ESXi using a scripted installation (aka Kickstart) and the KS.CFG is located on a CD-ROM device and you happen to be using a Nested ESXi VM and see the following message:

cannot find kickstart file on cd-rom with path -- /KS.CFG


You are probably using an IDE-based controller for the CD-ROM device, which the underlying IDE driver for ESXi has been removed as part of VMware Cloud Foundation (VCF) 9.0.


The fix is to simply remove the IDE controller and use a SATA controller and things will work as expected!

NVMe Tiering with Nested Virtualization in VCF 9.0

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The NVMe Tiering feature was first previewed with the release of vSphere 8.0 Update 3 and the feature is now officially supported with the release of VMware Cloud Foundation (VCF) 9.0! 🎉

Since the original tech preview, all major limitations and unsupported workload profiles that would prevent an organization from deploying NVMe Tiering in production has been resolved as part of the VCF 9.0 release.

Although Nested Virtualization is NOT officially supported, many users rely on Nested ESXi for testing, development, and learning purposes. With that said, if you have NVMe Tiering enabled on an ESXi 9.0 host and you attempt to power on a Nested ESXi VM or VM that is configured with Virtual Hardware-Assisted Virtualization (VHV), it will fail to power on with the following error message as shown in the screenshot below.


While it was possible to use Nested ESXi with the tech preview of NVMe Tiering, it was just not in scope as part of productizing NVMe Tiering for VCF 9.0.

All hope is not lost, while Nested Virtualization is still NOT officially supported by Broadcom, it is a very useful feature not just for our users but also for internal development purposes and after speaking with the tech lead for NVMe Tiering, this is something that will be addressed in a future update of VCF and this is just a short term limitation for now if you intend to run Nested ESXi workloads.

Enable TRIM/UNMAP from Nested vSAN OSA/ESA to physical vSAN OSA

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If you are running Nested vSAN Original Storage Architecture (OSA) or vSAN Express Storage Architecture (ESA) workloads on top of a physical vSAN OSA setup, you may want to enable the Guest TRIM/UNAMP capability, which would allow your the "inner" (Nested) workloads to pass the TRIM/UNMAP requests down into your physical vSAN OSA deployment for space reclamation.

It was recently observed that storage utilization may continue to increase on a physical vSAN OSA setup even when the Nested vSAN ESA/OSA workloads have already freed up their storage, which is due to the fact that the TRIM/UNAMP commands are not being passed down into the physical vSAN OSA. If you are using vSAN ESA for your physical setup, Guest TRIM/UNMAP is already enabled by default, so this is only applicable if you are using vSAN OSA.

To enable the Guest TRIM/UNMAP capability, you need apply the following ESXi Advanced Setting to your physical vSAN OSA.

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