Backup up a 'Deduped' Win 2012R2 Server

HI All

Using DP v9.xx we are backing up a Windows 2012 R2 File server with Deduped data drives.

We are backup up this server with a typical DP filesystem backup, and also a Third party VM replication tool. The VM replication tool appears to back up significantly less changes each backup than the DP Filesystem backup.

We think this may be linked to the deduped data drives?

Are there any specific options we need to enable or be aware of to effciently backup the deduped data drives.

Many thanks