I have a Mac and I use TimeMachine to backup it up to WHS. I installed WHS connector on Mac and created share on WHS called MAC with folder duplication set o "OFF". Within that share I created Mac "hard disk" using connector so it can be used by MAC TimeMachine.  My MAC fully loaded uses 120GB so I set MAC backup disk to 150GB. I was able to backup my MAC ok but I'm getting this error on WHS: 

Duplication is falling for shared folder: Mac. There is not enough free space available to maintain a copy on more than one hard drive.

My WHS has about 400GB free space left and I have turned OFF folder duplication for MAC share so I assumed this duplication refers to actual MAC backup hard drive that was created by WHS connector. How can I turn that off?  I don't want to created like 300GB disk for backups.