There are two things:
1) Check your /etc/messages logs on the NetApp storage controller to verify that snapshots for the volume aren't failing;
2) Test snapshots with 'snap create <volname> test' to see if you can take a snapshot.
If (2) fails, it's the same thing that VIBE is coming back with.
The ZAPI call you see below is essentially the same as creating a manual snapshot, and if you can't do that, that's the problem. It's almost certain to be the issue. If you use 'vol autosize' or a similar function it would allow the volume container to grow in advance of the snapshot.
One other point; if you are consuming a lot of snapshot space, you might want to make sure you aren't swapping within your VMs, which is going to blow up the amount of space needed for snapshots.
Thanks,
--Matt