No nfs SPN generated

Hey netapper

i'm configuring nfsv4 on netapp c-mode 9.1,there is a issue blocking me that is no nfs SPN generated on c-mode server after running

vserver nfs kerberos interface*> modify -vserver qavs2 -lif lif2 -kerberos enabled -spn nfs/qavs2-qacl6.qa.arkivio.com@QA.ARKIVIO.COM -admin-username administrator

qacl6::vserver nfs kerberos interface> show
               Logical
Vserver        Interface     Address         Kerberos SPN
-------------- ------------- --------------- -------- -----------------------
qavs1          lif1          10.17.16.108    disabled -
qavs2          lif2          10.17.16.109    enabled  nfs/qavs2-qacl6.qa.arkivio.com@QA.ARKIVIO.COM
2 entries were displayed.

only host/* SPNs returned,i believe they are created when joining c-mode to domain actually,also tried add nfs/qavs2-qacl6.qa.arkivio.com via ADSI EDIT on c-mode account get error saying added SPN is not unique in domain,any idea how can i make nfs/* spn comes up?

thanks

C:\>setspn -L -C qavs2-qacl6
Registered ServicePrincipalNames for CN=QAVS2-QACL6,CN=Computers,DC=qa,DC=arkivi
o,DC=com:
        HOST/qavs2-qacl6.qa.arkivio.com
        HOST/QAVS2-QACL6