The PNID is the Primary Network Identifier.
The upgrade from vCenter Server 7.x to 8.x fails because the PNID and the vCenter Server hostname do not match.
When changing the PNID in the vCenter Server Management Interface (VAMI), the vmware-stsd service fails to start, and the PNID domain is duplicated after the change.
Example: If you change the PNID from example to example.vmware.com, the PNID changes to example.vmware.com.vmware.com.
VMware vCenter Server 7.x
This issue occurs due to the following conditions:
This issue is caused by multiple issues.
Before performing the workaround below, please create an appropriate backup/snapshot of your vCenter Server.
Delete the LocalOS ID registered with the short name of the vCenter Server and register it with the ID [localos].
After completing the above steps, change the PNID.