Addressing vCenter FQDN and Hostname Case Mismatches

Products

• VMware vCenter Server 7.0
• VMware vCenter Server 8.0

Issue/Introduction

• In certain scenarios, a direct PNID update may fail if the destination PNID is too similar to the existing PNID. This behavior is commonly observed when:
  • Changing from a short hostname to a Fully Qualified Domain Name (FQDN).
  • Changing only the letter case of an FQDN (for example, from uppercase to lowercase).
    
    
• Example:
  • Current PNID: VCSA01.domain.local
    Target PNID: vcsa01.domain.local
  • A direct PNID change from VCSA01.domain.local to vcsa01.domain.local may result in validation or update errors due to the similarity between the source and destination names.

Environment

VMware vCenter Server 7.x

VMware vCenter Server 8.x

VMware vCenter 9.x

Resolution

One of the following workarounds can be followed to update the PNID of the vCenter:

Note: Take a snapshot of the vCenter Server Virtual Machine. If the vCenter is in enhanced linked mode, follow VMware vCenter in Enhanced Linked Mode pre-changes snapshot (online or offline) best practice.

WORKAROUND 1: Update the vCenter PNID (VCSA02.example.com) to localhost:

1. Login to the vCenter Appliance Management Interface (https://<VCSA_FQDN>:5480) as root.
2. Navigate to Networking -> Network Settings -> Edit.
3. Update the hostname with a placeholder. Example: localhost.
4. Reboot the vCenter Server. Do not skip this step as this is necessary to update the Likewise registry and restart the underlying services.
5. Update the hostname to vcsa02.example.com.

 

WORKAROUND 2: Configure Temporary PNID (exampleTemp.example.com):

1. Update the VCSA Hosts File:
   
   
   1. Backup the original configuration:
      • # cp /etc/dnsmasq.conf /etc/dnsmasq.conf.original
   2. Edit dnsmasq.conf to include the hosts file:
      • # vi /etc/dnsmasq.conf
      • Add the line: addn-hosts=/etc/dnsmasq.hosts
   3. Add the temporary PNID to /etc/dnsmasq.hosts:
      • # vi /etc/dnsmasq.hosts
      • Add the line: <vCenter_IP_Address> exampleTemp.example.com exampleTemp
   4. Restart the dnsmasq service:
      • # systemctl restart dnsmasq.service
   5. Test the name resolution:
      • # nslookup exampleTemp.example.com 
      • # nslookup <vCenter_IP>
        
        
2. Change the PNID to Temporary PNID in VAMI:
   
   
   1. Access the vCenter Appliance Management Interface: https://<vCenter_IP>:5480.
   2. Under Networking -> Edit, update the hostname to exampleTemp.example.com
      Note: It is recommended to add exampleTemp.example.com to the local hosts file of the web browser's PC to ensure accessibility to the VAMI interface.
      
      
3. Reboot the vCenter Server and verify the changes.
   
   
4. Remove Temporary PNID Configuration from Proxy DNS:
   
   
   1. Restore the original configuration:
      • # cp /etc/dnsmasq.conf.original /etc/dnsmasq.conf
   2. Delete the temporary hosts file:
      • # rm /etc/dnsmasq.hosts
   3. Restart the dnsmasq service:
      • # systemctl restart dnsmasq.service
        
        
5. Change PNID to Destination PNID (vcsa02.example.com) in VAMI:
   
   
   1. Access the vCenter Appliance Management Interface: https://<vCenter_IP>:5480.
   2. Under Networking -> Edit, update the hostname to vcsa02.example.com


6. Reboot the vCenter Server and verify the changes.

Additional Information

Japanese KB: vCenter Server の FQDN と Hostname の大文字小文字のミスマッチを修正する