By reading this note :
and from the previous thread (https://communities.netapp.com/message/42817#42817)I have understand that we can use DPM as the VSS Requestor.
I have problem with Snapdrive installation because of iSCSI initiator problem (case open with Netapp) and cannot install Snapdrive Service because it wants to manage the iSCSI connections and sessions. So I can't install Data Ontap VSS hardware provider, is there anything I can do to install the Hardware provider only to backup with DPM meanwhile ? The aim is to replace DPM with SMHV at the final step be we need to have a backup of the VM until the case is resolved.