How do I verify Direct NFS is being used by RMAN

I have a two node 11.2.0.2 RAC database running on AIX 6.1 TL6. We using NetApp storage for NFS. Direct NFS is configured using the /etc/oranfstab entries and the ODM libraries are loaded on each instance "Oracle instance running with ODM: Oracle Direct NFS ODM Library Version 3.0". Here are the contents of /etc/filesystems

/export:
        dev             = /vol/volnshr001_oraexport/oraexport
        vfs             = nfs
        nodename        = filer1
        mount           = true
        options         = rw,bg,hard,rsize=32768,wsize=32768,timeo=600,vers=3,proto=tcp,noac
        account         = false

/archivelogs:
        dev             = /vol/volnshr001_oraclearchive
        vfs             = nfs
        nodename        = filer1
        mount           = true
        options         = rw,bg,hard,rsize=32768,wsize=32768,timeo=600,vers=3,proto=tcp,noac