We re-enabled dedup on one of our volumes yesterday and observed the 'df-sh' savings go from 20% to 37%  (yay!)
but the volume usage jumped up

snap list revealed a big delta from our usual nightly snapshot delta:

> snap list vm65net
Volume vm65net
working...

  %/used       %/total  date          name
----------  ----------  ------------  --------
  0% ( 0%)    0% ( 0%)  Mar 01 13:47  irt-na03(1573989836)_vm65net.450 (snapmirror)
 37% (37%)   27% (27%)  Mar 01 00:00  nightly.0      
 39% ( 4%)   29% ( 2%)  Feb 29 00:00  nightly.1      
 41% ( 5%)   32% ( 2%)  Feb 28 00:00  nightly.2      
 42% ( 4%)   33% ( 2%)  Feb 27 00:01  nightly.3      
 43% ( 4%)   35% ( 2%)  Feb 26 00:00  nightly.4      
 44% ( 4%)   37% ( 2%)  Feb 25 00:00  nightly.5      
 45% ( 4%)   39% ( 2%)  Feb 24 00:00  nightly.6 

Is this expected behavior?
(when I noted these observations I was asked "doesn't dedup work on the snapshots too?")

thanks

Fletcher