I have a couple of vhdx files on a 2012 RC host.
One had deduplication run in the guest which cut down the used space from 250 gb to 125 gb. Compacting it ends in 3 seconds and it doesn't shrink at all, stays at 275 gb.
Another is just a standard vhdx from another guest that has 30 gb of used space, but the vhdx is 39gb. Compacting also ends immediately with no shrink.
Is compacting broken in rc?