Login using ssgconfig and select option 3 for Privlieged shell
After entering root credentials we get error:
SU: Permission Denied
Release : 10.1
After logging in with VM Vsphere console found that the password is incorrect via the error provided directly by the console.
root is only restricted via login with SSH (putty and like), but serial console (including vsphere) you can login directly as root for better errors/further troubleshooting.