SDDC Manager NSX Upgrade Precheck Fails - Error: "There are hosts in this NSX that are not known to SDDC Manager"

Products

• VCF Operations

Issue/Introduction

An NSX upgrade precheck to v9.x fails within SDDC Manager. The precheck remediation explicitly flags the following error:

There are hosts in this NSX that are not known to SDDC Manager: 

Where the ESXi hosts listed in the above error show as the shortname of the ESXi host and not the full name.

• Executing get nodes as user admin on the NSX-T Manager CLI displays the shortname in the Hostname/FQDN column for the affected hosts.
  
  
• Running hostname -f and esxcli system hostname get on the affected ESXi hosts returns the shortname instead of the Fully Qualified Domain Name (FQDN).
  
  
• Review of the host configuration in vCenter Server confirms there are no Host Profiles attached to these nodes enforcing standard naming conventions.

Environment

VMware Cloud Foundation 9.x 

ESX 9.x

NSX 9.x

Cause

The ESXi advanced host settings Misc.HostName and Misc.PreferredHostName are configured with the shortname rather than the FQDN. This misconfiguration introduces an identity mismatch between the ESXi hosts, NSX inventory, and the SDDC Manager database.

Resolution

To align host identities across the SDDC stack and resolve the precheck failure, enforce the FQDN on the affected ESXi hosts.

1. Update the advanced hostname values to the FQDN in the vCenter Server UI:

   • Navigate to **Cluster > Host > Configure > Advanced System Settings** and edit the following fields to the FQDN of the ESXi host:

     • Misc.HostName
     • Misc.PreferredHostName
       
       
2. Update the hostname via ESXi CLI on the affected nodes:
   

   esxcli system hostname set --host=<INSERT_FQDN>
   esxcli system hostname set --fqdn=<INSERT_FQDN>

    

3. Reboot the affected ESXi host cluster to apply the changes and ensure all services register the updated FQDN.
   
   
   
4. Verify the hostnames are correctly displayed as FQDNs via NSX Manager CLI (admin):
   

   get nodes

    

5. Perform a resync in VCF Operations and re-run the NSX upgrade precheck to clear the error:
   
   • VCF Operations > Inventory > VCF Instances > VCF domain > Actions > Sync Inventory.