We have a single AD domain and forest. We want to install multiple AD-Connect servers to prevent a single point failure. We use Password Through Authentication method.
Can we have multiple servers in active mode so we do not need to worry about bringing a staging server back in operation ?
No, multiple active connectors from single forest to single AAD is not supported. You can only have one active connector in your case.
We have two separate data centers,
We would like to have two active AD-Connect so if one datacenter fails the other AD-connect will work without manual intervention. Kind of HA, no?
It doesn't matter how many datacenters. As long as they share the same AD forest, and the same AAD, you can only have one active connector. However, whether you want to make a backup of the current good state connector and have it ready at another site, or leverage vSphere cluster HA, is up to you. The bottom line is it can only have one active connector running at a time.
Hi you cannot have more that one active server and it's mentionned in the documentation :
"Only one synchronization server can be in the primary role and actively exporting configuration changes to Azure. All other servers must be placed in Staging mode."
However the migration process is pretty easy if you have staging server ready to use in case of datacenter failure
How to import and export Azure AD Connect configuration settings | Microsoft Docs
