
If you have a vCenter that was dead, removed, or only not in use anymore but was in linked mode, you will receive warnings every time you open the master vCenter, so in this blog post, we will explain how to remove a dead vCenter Linked Mode.
Has we can see in the next image, in one part, we have the warning regarding an old vCenter that is set to linked mode with this vCenter, but in the next, in the Linked vCenter Server Systems tab, we don’t any vCenter added, and the list is empty.
Warnings

In this case, it was an old vCenter that was never removed, and the master was upgraded some times until version 6.7, but always had this dead link attached to it.
Login to your vCenter console to check what links or registers are enabled to this vCenter.
How to remove dead vCenter Linked Mode.
First, we check if this vCenter has an external PSC using: /usr/lib/vmware-vmafd/bin/vmafd-cli get-ls-location –server-name localhost
Next, is to list all the nodes that are register in this vCenter using: /usr/lib/vmware-vmafd/bin/dir-cli nodes list
[email protected] [ ~ ]$ /usr/lib/vmware-vmafd/bin/dir-cli nodes list
Enter password for [email protected]:
Node: vcenter.york.local
Type: PSC
Site: default-site
Partner #1: ldap://192.168.2.32
Node: 192.168.2.32
Type: PSC
Site: Default-First-Site
Partner #1: ldap://vcenter.york.local
[email protected] [ ~ ]#
As we can notice, the vCenter (vcenter.york.local) that we have a warning is still listed in the nodes. So we need to remove that node from the vCenter and break the linked mode between this vCenter and the dead one.
Next, we need to run the command to unregister this vCenter, using: cmsso-util unregister –node-pnid 192.168.2.32 –username [email protected]
Note: Before running this command, beware that this will restart your vCenter services, and vCenter will be unavailable during the process.
[email protected] [ /var/lib/sso-user ]# cmsso-util unregister --node-pnid 192.168.2.32 --username [email protected]
Password:
Solution users, computer account and service endpoints will be unregistered
2021-12-05T16:25:23.263Z Running command: ['/usr/lib/vmware-vmafd/bin/dir-cli', 'service', 'list', '--login', '[email protected]']
2021-12-05T16:25:23.310Z Done running command
Stopping all the services ...
All services stopped.
Starting all the services ...
Started all the services.
Success
[email protected] [ ~ ]#
Check again the vCenter node list and the vCenter is removed.
[email protected] [ ~ ]$ /usr/lib/vmware-vmafd/bin/dir-cli nodes list
Enter password for [email protected]:
Node: vcenter.york.local
Type: PSC
Site: default-site
[email protected] [ ~ ]#
For the safe side, I rebooted the vCenter, and now the warning is gone, and all is green.
I found this information helpful when rectifying my own issue with a stall vCenter linked environment. Credit to Luciano Patrao.