Hi Uwe,
There are lot of snapshot based reports in OnCommand 5.0 but they are in the operations manager console and not in the oncommand console. Pls take a look at the following GSS course which details on the reporting capability with OnCommand 5.0.For an in-depth training take a look at the GSS course for Reporting with OnCommand 5.0
http://learningcenter.netapp.com/dmsv2/SSORedirectionService?ObjectType=WBT&ObjectID=00232738
lnx:~ # dfm report list | grep -i snapshot
aggregates-snapshot-thresholds snapshot thresholds for all aggregates
aggregates-snapshot-capacity capacity being used by snapshots on aggregates
volumes-snapshot-counts Number of snapshots in volume
volumes-snapshot-growth rate of growth of volumes over time
volumes-snapshot-details Details of snapshots on volumes
volumes-snapshot-policies Snapshot Policies on volumes
volumes-snapshot-autodelete Snapshot Policies on volumes
volumes-first-snapshot Space used when taking the first snapshot
volumes-first-snapshot-percent Space used when taking the first snapshot
volumes-snapshot-capacity capacity report for all snapshot areas
volumes-snapshot-thresholds thresholds for all snapshot areas
volumes-first-snapshot-thresholds thresholds for first snapshots
lnx:~ #
Regards
adai