ADSM does that and has for years.
Why NetApp and IBM won't get together (I don't know how much they have discussed) to deliver a native ADSM client that can run inside a NetApp filer, I don't know. For all that some people complain about ADSM, it just works. It makes excellent use of a tape pool and doesn't require directly-attached tape.
A native client that runs under ONTAP would avoid the overhead of NFS.
Barry Lustig wrote:
Do any of the available backup solutions support a "dump to disk mode" like amanda? Amanda uses the disk on the local backup machine as the cache. After the backup completes to disk amanda dumps that file to tape. This takes care of the streaming issues. This of course would be a problem with large NetApp filesystems. But imagine if the packages (veritas, legato, workstation solutions, etc.) took the incoming data stream and wrote it as configurable chunks (100Mb, 1GB, etc.) to disk. They could then flush those chunks to tape.