invoke-ncsnapmirrorupdate or resync for svm-dr

I'm just curious if i'm missing something.


destination volume is required in both those cmdlets.


Well with svm-dr the command on the CLI is


snapmirror resync vservername: or snapmirror update vservername:


if you try to run 


invoke-ncsnapmirrorupdate it will fail b/c there is no destination volume, or if you try a volume you will get it's a member of a constituent.  


I know this must be something simple, Anyone?