As an interim position with one client, we were using NFS to mount NetApp exports on a Mac server and then performing backup to disk within OS X. NetApp then took care of snapshots and off-site replication.

We've now completed migration to NetApp CIFS by moving the last 100 GB of data from the Apple OS X server to a NetApp filer, using some great tools to perform renaming operations. We also have a great tool set for data migration/synchronisation that we used in this instance; the total data set was 1.5TB in size.

The renaming is necessary as many of the files created on Mac clients (via AFP) have file names that are  'illegal' in an SMB/CIFS environment (like trailing spaces and illegal characters).