HyperV and Reducing Size of CentOS Guest using GParted
There are so many articles that discuss reducing the size of a VHD or VHDX Hyper-V Guest. Some work great, others don't. The method described here is a bit complex, but it works every time.
First make a copy of the virtual disk that is going to be reduced in size.
Second, clean up any unnecessary files to further reduced its size of the virtual disk.
Boot from an ISO Image of GParted (look it up)