Resize Azure data disk error when not between 20 and 1023 GB

Q. I'm trying to resize an Azure disk but I get an error when I try and shrink a disk below 20 GB?

A. 20 GB is the smallest size for an Azure VHD while 1023 GB is the largest. Attempting to resize a disk outside of these limits will result in an error. Also remember that when shrinking a VHD there must be sufficient unpartitioned space inside the VHD to allow the disk to be shrunk to the requested size, i.e. you cannot shrink a disk to 50 GB if there is 60 GB of partitioned space inside the VHD.