From: http://www.cosonok.com/2013/12/a-difference-in-clustered-ontap-v-7.html
For Reference: To Force Delete the SnapMirror Snapshot
na81::> set diag
na81::*> snapshot delete -vserver vs1 -volume testshare -snapshot snapmirror.15991611-422d-11e3-8578-123478563412_9_2147484694.2013-11-30_142009 -ignore-owners true
Warning: This Snapshot copy is currently used as a reference Snapshot copy by one or more SnapMirror relationships. Deleting the Snapshot copy can cause future SnapMirror operations to fail. Are you sure you want to delete ‘snapmirror.15991611-422d-11e3-8578-123478563412_9_2147484694.2013-11-30_142009’ for volume ‘testshare’ in Vserver ‘vs1’? YES
rsr72 