Backup of Archives on NetApp

EV Version: 10.0.4
OS: Windows 2008 R2

Backup Software: NetBackup 7.5
Storage of Archives: NetApp

We would like to backup the archives stored on NetApp using NetBackup. However the when the backup is taken via the EV agent for NetBackup, it fails. Please advise on what is the recommended backup method when archives are stored on NetApp. I would like to know is it done using the EV backup agent or using some other method like NDMP?

Thanks!