CLI shows the "Volume in use" error when you dismount the ReFS data volumes on the Secondary RVG.

When you dismount the ReFS data volumes on the Secondary RVG, you may get the following error message "Volume in use" even when no drive letter has been assigned. This happens because, when an RLINK is attached on the Secondary RVG, the volume is marked as read-only, andVVR is unable to lock the volume. (3789197)