I've got an existing VM with 3 VHDX files and running on a Windows Server 2012 R2 Hyper-V host.  The VM is already configure with "Hyper-V Replica", and has been replicating successfully to a DR Site host for several months now.  I've recently added a new VHDX to the VM of source server.  This new virtual hard drive (4th VHDX) is not being replicated with the replica server VM.  How can I add this VHDX file for the replication without disturbing existing settings?

In addition to that, As I have tested the other way, I've removed replication from both sides and copied the intended vhdx file to replica site. Enabled the replication again as a fresh with "Use an existing virtual machine on the Replica server as the initial copy" option. But there was giving an error while finishing it.

Unfortunately, hot add of VHD files to an existing replicated virtual machine is not supported. You will need to reconfigure the replication from the begining. This feature will be added on Windows Server 2016. We will have to wait.

Dear Samir

Thanks for your information.