Firstboot fails when upgrading vCenter Server Appliance 6.7 with no DNS records (57126)
Cause
This issue occurs when deploying a vCenter Server Appliance 6.7 with an IP address that has no DNS record configured. IP based deployments without DNS are not supported.
Resolution
To resolve this issue, ensure to verify that the IP address has a valid (internal) domain name system (DNS) registration before deploying a vCenter Server Appliance 6.7 with a static IP address.
VMware KB:Firstboot Failed during Install, Deployment, Upgrade, or Migration in vCenter Server and vCenter Server Appliance 6.7 (55746)
VMware Communities:Solved: VMWare VirtualCenter 6.7 failed firstboot -->https://communities.vmware.com/thread/592783