Should I use the same storage for OS part and Backup DB part?

We are trying to set up Linux server for the backup server, and are using NetApp storage for the both OS part and Backup data part.

We have two different type of stroage both from NetApp. One is FAS which has a lot of storage based functions, and support NFS, SnopShots, DR replications. The other one is E-series has less functions and primarily for the backup data images. Should I seperate OS and Data part , one on FAS, and the other on E, or does that matter.

Thanks!