DFS root replication

Hi All. 

i have the following setup: 

1 root server (domain controller)

2 x DFS targets on separate file servers replicating between each other. 

Now unknown to me it looks like the targets also replicates ALL data from the DFS targets to the root server (domain controller) which has limited disk space. I therefore need to migrate all data off the domain controller. Is there a best way to do this and also is there any documentation which describes how the root replicates data (I cannot find ANY documentation on this front). I want to keep the existing DFS target server and replication.

My assumption on replication stems from the fact that when you configure member replication for a folder, it does not automatically add the root server.. 

Any advise would be greatly appreciated.

Thanks!