doing that alone wil not move the data files to the new disk, it will just add new data to the new disk,
YOur best bet is once you change the drive specification, export the data from a cube, clear the data from the cube and then re-import it. that will put it on the new drive. Repeat the process for each cube you want to move.
I can't remember if it is true for drive changes, but it is always a best pracitce to stop the application ater makeing any property changes