VDM will not reverse replication?

I have tried to reverse replication on a VDM, but the VNX5500 system fails the task saying that the interface is use by VDM?

The VDM that I am trying to reverse replication on has file systems mounted and replicated.

I can reverse the file systems but not the interface, and I need to change the "DR" site to the "Live" site.

I don't want to break the link between the replication of the VDM or File systems that are being replicated (they took two weeks to synchronise last time).

Are there any commands that I can run to see what VDMs are using an Interface?

Any help is very much appreciated.