We use a NetApp FAS 6-series filer with an application that spans multiple volumes. For backup purposes I would like to create a consistent snapshot that spans these volumes at the same point in time (or at least with an extremely low delta); additionally, we'd like to to use SnapMirror to replace the production environment to test volumes.

The problem is in creating a consistent snapshot/SnapMirror, since these commands are not transactional and do not take multiple parameters. I tried scripting consecutive "snap create" or "snapmirror resync" commands via SSH, but there's always a 0.5-2 second difference between each snapshot. It's currently "good enough", but I'm seriously concerned about the consistency impact with increased load (we're currently in pre-production).

Has anyone managed to create a consistent snapshot that spans several volumes? How did you pull it off?