While adding an additional vCenter Server to our Multi-Site Single Sign On instance I encountered a problem as I entered the details of the existing SSO.
The error thrown was:
User credentials are incorrect or empty. Provide correct credentials.
After a couple of hours online with VMware support I took a guess at the problem. On the existing Single Sign On Configuration I have added the Active Directory domain DefinIT and in order to enable integrated authentication from the vSphere Client I moved it to the top of the list - this meant that System-Domain is no longer the default authentication domain.
VMware vSphere Single Sign On (SSO) can be installed in Multi-site mode to support local sign-on to vCenters that you want to be part of the same single sign on domain - for example, if you want to install Linked-Mode and have the advantage of a single pane of glass view, but can’t risk using a single SSO instance across the WAN. In other words, from VMware’s blog post: