This is one of the common misunderstandings with snapvault...
With snapvault you have the source volume/qtree (data you want to backup).
And you have the destination volume/qtree where the backup data shall be written to (sort of like a tape).
you have local snapshots on the source (snapvault snap sched ..... )
and you have snapshots on the destination (snapvault snap sched .....)
in addition you create snapvault snap scheds to transfer the data from the source to the destination (with the -x parameter) and in order to be able to transfer the data, snapvault creates or uses snapshots to do this.
e.g. snapvault snap sched -x source:/vol/qtree destination:/vol/qtree sv_daily .....
So you define the snapshot retention on the source, then on the destination and the transfer schedule, thats it!
Excerpt from the manpage:
The third configuration step is to establish the SnapVault snapshot schedules on the primaries and the secondary with the snapvault snap sched command. A snapshot schedule in a volume creates and manages a series of snapshots with the same root name but a different extension such as sv.0, sv.1, sv.2, etc. (For snapshots on SnapLock secondary volumes, the extensions are representations of the date and time the snapshot was created rather than .0, .1, etc.). The primaries and secondary must have snapshot schedules with matching snapshot root names. On the secondary, the -x option to the snapvault snap sched command should be set to indicate that the secondary should transfer data from the primaries before creating the secondary snapshot. If -x is set, when the scheduled time arrives for the secondary to create its new sv.0 (or sv.yyyymmdd_hhmmss_zzz for SnapLock volumes) snapshot, the secondary updates each qtree in the volume from the sv.0 snapshot on the respective primary. Thus, the primaries and secondaries need snapshot schedules with the same base snapshot names. However, snapshot creation time and the number of snapshots preserved on the primary and secondary may be different.