VCF 9 Installer Validation Found Less Than Two Uplinks For The DVS

Installing VMware Cloud Foundation (VCF) 9 in a lab often means using less than ideal hardware configurations. In my case, I have ASUS Intel NUCs that have only one physical NIC for an uplink. Recommendations dictate you should have at least two for redundancy and the VCF Installer checks this. If you have less than two uplinks, VCF Installer will block the deployment. There is a way around this and it is simple.

I received the following details when the VCF Installer was validating existing components:

VcManager <vCenter FQDN>: Found less than two uplinks for the DVS <distributed virtual switch name>

Remediation: Please ensure a minimum of 2 configured uplinks for each DVS.

This is because I had only one uplink configured for the DVS. Getting around this was easier than I thought. I assumed I needed two physical NICs on each host. It turns out I only need two uplinks configured--even if one of the uplinks does not have a physical NIC backing.

I proceeded to the Network section of the vSphere Client, right-clicked the DVS, clicked Settings, and then Edit Settings.

I clicked Uplinks in the Distributed Switch - Edit Settings popup window, added an uplink, and clicked OK.

I re-ran the VCF Installer validations and everything succeeded.

Cross vCenter vMotion with Different Distributed Switch Versions

Cross vCenter vMotion enables live VM migrations from one vCenter environment to another. This prevents downtime when migrating between these two separate environments. An example use case is moving workloads from a vCenter 8U3 environment to a new VCF (vCenter) 9 deployment. However, by default, vMotion does not allow live migration of VMs across different virtual distributed switch (VDS) versions. There is a workaround.

In our example above, this would be migrating VMs from a VDS 8.0.3 to a VDS 9.0.0. When attempting this cross vCenter vMotion, you get this error:

The target host does not support the virtual machine's current hardware requirements. The destination virtual switch version or type (VDS 9.0.0) is different than the minimum required version or type (VDS 8.0.3) necessary to migrate VM from source virtual switch.

The workaround: Add the following advanced setting to the source and destination vCenter instances. Follow these steps:

1. In the vSphere Client, go to Inventory and click on the vCenter instance.
2. Click Configure.
3. Select Advanced Settings.
4. Click the Edit Settings button.
5. Scroll to the bottom of the popup window.
6. Enter config.vmprov.enableHybridMode in the Name field.
7. Enter true in the Value field.
8. Click the Add button.
9. Click the Save button.

IMPORTANT: Test a few migrations using non-critical workloads first. This is an advanced setting and there have been a few reports of networking issues after a VM was migrated, e.g., loss of static IP settings.

Optional: Revert the setting by changing Value to false after the migrations are complete.