Improper decommissioning of the 6.x PSC node or any vCenter from ELM might leave stale service registrations on the vCenter which leads to other issues.
Steps to check stale registrations on vCenter Server:
/usr/lib/vmware-lookupsvc/tools/lstool.py list --url https://localhost/lookupservice/sdk --no-check-cert > /tmp/psc.txt
less /tmp/psc.txt | grep -i "Service Type: " | sort | uniq -c
/etc/vmware/install-defaults/vmdir.ldu-guid to compare Node ID from above file (/tmp/psc.txt):
/etc/vmware/install-defaults/vmdir.ldu-guid.VMware vCenter Server 7.x
VMware vCenter Server 8.x
Improper decommissioning of external PSC or vCenter in Enhanced Linked Mode (ELM).
Follow the below steps to remove the stale service registrations from vCenter Server using the service_unregister_stalenode.sh script.
./service_unregister_stalenode.sh <Node_ID of stale node>
Note: This script will not remove service registrations that do not have node IDs; example: sso:groupcheck, sso:admin.