Remove enhanced link mode

Products

• VMware vCenter Server

Issue/Introduction

• Decomissioning or removing a vCenter server in Enhanced Link Mode (ELM)

Environment

vCenter Server 7.x

vCenter Server 8.x

Resolution

NOTE: ENSURE OFFLINE SNAPSHOTS OF ALL VCENTERS IN THE SSO DOMAIN AND/OR BACKUPS ARE IN PLACE BEFORE STEP 6 IS RUN.

1. Power Off all vCenter Servers in the same SSO domain (ELM domain).
2. Take offline snapshots of all VCSA's by logging directly into ESXi host UI (https://esxihost/ui) for all vCenter servers in ELM.
3. Power On the remaining (except the VCSA that is being removed) VCSA(s).
4. Open an SSH session to one of the other working VCSA(s) within the same SSO domain via root.
5. Run the shell command to start the Bash shell and log in, if needed.
6. Run the cmsso-util unregister command to unregister the vCenter Server Appliance that you want to remove
   cmsso-util unregister --node-pnid vCenterServer_System_Name --username [email protected]
   
   

   Where vCenter_Server_System_Name is the PNID (usually FQDN) of the vCenter Server Appliance (VCSA) that is to be decommissioned or removed and vsphere.local is the SSO domain name.
   It will then prompt for the [email protected] password.  
   
   Note: There is downtime involved in executing the cmsso-util unregister command. It will restart the services on the node where it is being run.

7. Finally, once everything is verified as stable, delete the vCenter Server Appliance that is no longer needed from the vSphere inventory.  
8. Remove/commit any snapshots on the remaining VCSA(s).

Additional Information

Using the cmsso command to unregister vCenter with External PSC or vCenter with Embedded PSC from Single Sign-On