Deploying VCF 9.0 on a single ESXi host?

By default, the VMware Cloud Foundation (VCF) 9.0 Installer requires a minimum of 3 ESXi hosts when you select vSAN (OSA or ESA) for storage or 2 ESXi hosts when you choose to use external storage (Fibre Channel VMFS or NFS). When compared to VCF 5.x where vSAN was the only storage option and it required a minimum of 4 ESXi host, this is certainly a welcome change for our users.

With VCF 5.x, it was possible to deploy using just a single ESXi host for the VCF Management Domain and this question has certainly come up a few time since the GA of VCF 9.0 ...

So what happens when you only enter a single ESXi host into the VCF Installer?

As expected, we see a validation error stating that we have not met the minimum number of ESXi hosts ...

However, this is just the default behavior and of course this was something I had looked into early on with VCF Engineering, since this would be an extremely useful capability to allow our users to easily explore VCF 9 using the smallest number of ESXi hosts for lab purposes only, assuming you can meet the Minimal Resources to Deploy VCF 9.0 in a Lab.

Enough teasing ... lets get to the goods! 😁

We do have a configuration override that can be added to the VCF 9.0 Installer, allowing you to use either a single or even dual hosts, depending on the amount of available resources you have on each host and the capabilities you plan on using as additional hosts may still be needed for setting up a VCF Workload Domain or deploying additional VCF components.

Disclaimer: This is not officially supported by Broadcom, please use at your own risk.

Step 1 - Deploy the VCF 9.0 Installer and ensure that it is up and running

Step 2 - Run the following command to append the required configuration:

echo "feature.vcf.internal.single.host.domain=true" >> /home/vcf/feature.properties

Step 3 - Restart the VCF Installer services for the change to go into effect:

echo 'y' | /opt/vmware/vcf/operationsmanager/scripts/cli/sddcmanager_restart_services.sh

Note: This setting is applicable for both VCF Management and Workload Domain, since the VCF Installer can turn into SDDC Manager, which means it will have the settings or it will be deployed with the setting as that is what the source VCF Installer has configured.

Step 4 - While this workaround allows you to use less than the required number of ESXi hosts, the VCF Installer UI still enforces the minimum host check, I suspect this is due to UI hardcoding the validation checks.

The workaround is to not use the interactive workflow, which will not allow you to proceed until you enter three valid ESXi hosts but to use JSON method of deployment. You can still use the VCF Installer UI, but instead of the interactive wizard, simply upload your JSON that contains the single or dual ESXi host reference and proceed directly to the validation, which will pass and you can begin your deployment.

So what are some ways in which you can deploy VCF 9 using this new trick?

If you have a physical host that can meet the Minimal Resources to Deploy VCF 9.0 in a Lab, then a single ESXi host can certainly allow you to easily deploy the full VCF 9 solution, there are plenty of powerful workstations to server grade hardware that can already do this, no different than say VCF 5.x but if you are looking at consumer grade hardware, there are definitely resource constraints that will require you to use more than a single host.

For example, I have been playing with the Minisforum MS-A2, which I will have a thorough write-up on and after countless hours of testing, debugging ... I have found that even though it meets the CPU core requirement, having just a single host is not sufficient due to the memory demands required by VCFA and this is with NVMe Tiering enabled! While I am still not giving up, I would say to get the best possible experience, you will need to have at least two MS-A2 to not only deploy VCF 9, but doing something useful with it afterwards, which ultimately is my goal!

The GMktec K11 or K8+ is another popular set of kits, however they do not meet the minimum CPU core requirement, which would prevent you from deploying VCF Automation (VCFA) out of the box. The rest of the VCF 9 components can deploy without any issues and I have it running with vSAN ESA and since these systems only support two NVMe devices, you also need to apply this workaround to or you can simply use external NFS storage as an alternative.

Currently, I do NOT have 2 x MS-A2 and thanks to this recent workaround, which I had just published last week, I was able to deploy VCF 9 using both a Minisforum MS-A2 and GMktec K11, both of which support 128GB of memory but are from two different hardware vendors.

The benefit here is that the VCF Automation (VCFA) appliance can run on the MS-A2 which can support the higher vCPU requirement and the other appliances can be spread across the MS-A2 and another system that only has 8 Cores / 16 Threads, which can help from a budgeting standpoint.

While you can mix/match your hardware using this additional workaround, if you ask my personal opinion, I would say invest in a uniform hardware setup as it will only give you a better experience in the long run and remember, this is an investment in yourself, not necessary the physical thing that you just bought and need to justify to your significant other 😉

Lastly, I also want to share that I will have a VMware Explore session that will deep dive into deploying VCF 9.0 for a lab environment including more tips and tricks, so be sure to sign up for #CLOB1201LV Deploying Minimal VMware Cloud Foundation 9.0 Lab