Many Thanks, very qualified answer! Perfect working now with dpReaperInterval=1minute and Orphaned.
 
But was quite surprised when I used dpdpReaperInterval=1minute with "automatic" old mirrors retations-ships where not deleted. Only after changing back to Orphan, may I overlooked time settings an needed to wait more time. 
 
 Did I understand right, secondary volumes which are not part anymore of Datasets,  however never deleted ?
 
Other remarques: Why Volumes once in Datasets are not 100% cleanuped, means they stay internelly in Sybase DB 
when you delete Datasets and all Volumes. Why we need to clean up manually with
dfm volume delete -f {ID of volume} z.B dfm volume delete -f all
 
I mean, if Operator is realing delting resources then sould be wipped out and not if you recreate that volumes are created with volume_1...volume_2.. etc.
 
May would be good to change that in code thate delete is really delete.
 
But many thanks