Explanation
To cache on-premises ONTAP volumes into the cloud with Cloud Volumes ONTAP, you need to use the FlexCache feature, which creates a writable, persistent cache of a data volume that is consistent and coherent with its original data set and stored in a remote location. FlexCache supports both SMB and NFS protocols, which are the traditional file access protocols for Windows and UNIX/Linux systems respectively. You can control file access using UNIX-style permissions, NTFS-style permissions, or a mix of both. Clients can access the same files using both SMB and NFS protocols123.
NVMe and iSCSI are not supported by FlexCache, as they are block protocols that run on standard Ethernet networks. FlexCache is a file-based solution that works with file protocols only12. References
:- Client protocols | NetApp Documentation, Client protocols - NetApp, Cloud Volumes ONTAP for AWS: Storage for the Cloud Era.