You can extend the retention period of a WORM Snapshot copy.
snapvault snap retain wormvol sv_hourly.20050513_195442_GMT 2y
***WARNING: YOU ARE REQUESTING SNAPLOCK RETENTION OF A SNAPSHOT***
This operation will enforce the retention of the snapshot by
SnapLock for the specified retention period. You will NOT be able
to delete the retained snapshot until this retention period has
been satisfied. The relevant information for confirmation of this
operation is as follows:
Volume: wormvol
Snapshot: sv_hourly.20050513_195442_GMT
Retain until: Fri Feb 17 00:00:27 GMT 2006
Are you REALLY sure you want to retain this snapshot? Y