Technical

Changing your vCenter Server’s FQDN

*Blog UPDATED as of September 10th*

A popular feature request recently has been the ability to rename a vCenter Server appliance (VCSA). I am not referring to renaming the virtual machine (VM) as that is the inventory name of the VM. I am referring to the Fully Qualified Domain Name (FQDN) or hostname of the vCenter Server. This name is also known as the PNID (Primary Network ID) within vCenter Server. I am happy to report that this feature is available in vCenter Server 6.7 Update 3!

Why Would I Rename My vCenter Server?

You might be wondering why would you want or need to change the FQDN of the vCenter Server. Consider this scenario, your company is phasing out its vSphere 6.0 (EOL for vSphere 6.0 is 3/12/2020) environments of which each environment is also managed by one or more vCenter Servers for Windows. Let’s also consider that system naming standards are enforced for both Linux and Windows operating systems.

When the vCenter Servers for Windows are upgraded and migrated to the VCSA, the migration process preserves the FQDN of the older Windows Server as it stands up the newly deployed vCenter Server appliance with the same name. Before and after migration, customers struggle with the requirement of updating FQDN and hostnames for the new vCenter Server as it is no longer a Windows Server and should follow different naming standards per operating system type. Changing the FQDN of the vCenter Server can also be helpful to support mergers & acquisitions where server naming conventions may differ between firms.

Changing the vCenter Server’s FQDN or PNID has not been supported in previous versions of vSphere until now in version 6.7 Update 3. This new feature allows customers the flexibility to rename the vCenter Server’s FQDN in a supported manner. Join me as we go over the process of making this change.

 

Prerequisites

In order to take advantage of this new feature in vCenter Server, you will need to be running vCenter Server 6.7 Update 3. SSO Domain Administrator (example: [email protected]) credentials will also be required to perform this change. Once on the correct software version and credentials handy, next make sure that you have taken a few moments to consider the following prerequisites for a vCenter Server that will be renamed:

  • Backup all vCenter Servers that are in the SSO Domain before changing the FQDN of the vCenter Server(s)
  • Supports Enhanced Linked Mode (ELM)
  • Changing the FQDN is only supported for embedded vCenter Server nodes
  • Products which are registered with vCenter Server will first need to be unregistered prior to an FQDN change. Once the FQDN change is complete they can then be reregistered.
  • vCenter HA (VCHA) should be destroyed prior to an FQDN change and reconfigured after changes
  • All custom certificates will need to be regenerated
  • Hybrid Linked Mode with Cloud vCenter Server must be recreated
  • vCenter Server that has been renamed will need to be rejoined back to Active Directory
  • Make sure that the new FQDN/Hostname is resolvable to the provided IP address (DNS A records)

NOTE: If the vCenter Server was deployed using the IP as PNID/FQDN, then the following should also be considered:

  • The PNID change workflow cannot be used to change the IP address of vCenter Server
  • The PNID change workflow cannot be used to change the FQND of vCenter Server

In this scenario, use the vCenter Server Appliance Management Interface (VAMI) to update hostnames or IP changes directly. 

As a first step in preparing to rename the vCenter Server, a File-Based Backup of the VCSA should be obtained at the very least. If currently using Image-Level backups for the vCenter Server, please be sure to perform those backup jobs too.

Next steps will be the creation of Forward & Reverse DNS records for the new hostname that the VCSA will become. This concept is common when renaming a computer object within Active Directory. Once DNS A records are updated for the new FQDN of the VCSA we can move to begin the renaming process.

Changing FQDN of vCenter Server

The FQDN change is integrated within the Virtual Appliance Management Interface (VAMI). From the vSphere Client navigate to MENU>>System Configuration and select the vCenter Server to rename. Click the Login button to be routed to the vCenter Server VAMI on port 5480. As an alternative, you may go directly to the vCenter Server VAMI interface (https://<FQDN-of-VCSA>:5480) instead of via the vSphere Client’s System Configuration console.

 

Login to the vCenter Server (via VAMI)

Login to the VCSA with the ‘root‘ administrator account.
vCenter Server 6.7U3

 

From the Summary page, review the current FQDN of vCenter Server. Click on Network to continue.
vCenter Server 6.7U3

Network interfaces are displayed on the right under Network Settings. Click Edit continue.
vCenter Server 6.7U3

The details of the network adapters are shown in the wizard. Be sure to select NIC 0 (Management Network) then click Next.
vCenter Server 6.7U3

Expand the Hostname and DNS field to make edits. Change the vCenter Server’s Hostname, or FQDN, to its new desirable name then click Next to continue.  NOTE: Be sure that Forward & Reverse DNS records are in place prior to continuing.

vCenter Server 6.7U3
(vCenter Server before FQDN Change)
vCenter Server 6.7U3
(vCenter Server after FQDN Change)

Next enter the SSO Administrator credentials for the vCenter Server. NOTE: Do not use the ‘root‘ account login for this action.
vCenter Server 6.7U3

Review the requested changes to the vCenter Server’s FQDN & IP settings.
vCenter Server 6.7U3

Scroll down to check the acknowledgment that a vCenter Server backup has been taken, as well as unregistering any extensions. IMPORTANT: Please review the Next Steps. These additional actions will need to be reconfigured after the FQDN of the vCenter Server is changed.

The requested Network changes (FQDN/IP) will begin by stopping services, updating certificates, modifying the registry & network settings, etc.

vCenter Server 6.7U3
(Stopping Services)
vCenter Server 6.7U3
(Updating Network Configurations)
vCenter Server 6.7U3
(Restarting Services)

Once all changes have been applied, an alert will be displayed allowing the redirection back to the Virtual Appliance Management Interface (VAMI) on port 5480 within 10 seconds. An option to Redirect Now is also available to skip the automatic redirect.
vCenter Server 6.7U3

Login once again to the vCenter Server on port 5480 (https://<FQDN-of-VCSA>:5480)
vCenter Server 6.7U3

From the Summary page, we can verify that the new vCenter Server FQDN has been applied. View the Hostname at the top of the screen.

vCenter Server 6.7U3

The new vCenter Server Hostname/FQDN can also be validated from the Networking menu, then reviewing the Hostname under Network Settings. At this point, the vCenter Server’s name has been successfully changed.
vCenter Server 6.7U3

 

REMINDER!

Continue with the Next Steps of additional settings & actions that must be reconfigured after a vCenter Server Hostname/FQDN change. Failure to complete these steps may have an impact within your vSphere environment. If any failures occur with changing the FQDN, the recovery process is to restore vCenter Server from Backup, recreate replication and vCenter HA (VCHA).

Next Steps include:

  • Products registered with vCenter Server will need to be reregistered
  • All custom certificates will need to be regenerated
  • vCenter HA (VCHA) will need to be reconfigured
  • Hybrid Linked Mode (HLM) with Cloud vCenter Server has to be recreated
  • Active Directory will need to be rejoined

 

Closing

As we wrap up this post it’s important to remember that changing a vCenter Server’s FQDN can have a large impact on other services & settings if all steps are not followed. This goes for both Prerequisites and Next Steps (after changes are complete). Proper planning is key for any type of change, the same holds true for Hostname/FQDN changes to vCenter Server. Be sure to have validated backups of the vCenter Server (File-based or Image-level backups are both supported). Also, keep track of all 2nd or 3rd party tools that communicate with vCenter Server so they can be reconfigured after.

I have also posted a new Product Walkthrough (PWT) on vSphere Central for those that would like to try this new feature prior to using it in a lab or production.