Netbackup and VVR

Hi All, 

I am still very new about VVR and Netbackup. I have some questions:

1. Which volume should the VVR replicate, the whole /usr/openv or only the catalog directory?
2. Currently our SI configure to replicate the /usr/openv, is it correct?
3. Any tip on Netbackup & VVR best practises? I have searched the Internet but couldn't find a good one. 

We are using the Netbackup 7.5 on RedHat (6.3) platform. 

Regards, 

Iwan