Center Marks & Dimensioning

Hello,
I have a part (cylinder) with several through holes which are perpendicular to the cylinder and run through the length of the cylinder's shaft. I want to create center marks on the through holes or dimension between any of the through holes but unable to do so, can any one help me with some sort of solution.
Thanks in advance.

Hi,
Select the edge of the perpendicular through hole in the drawing and convert entities, then apply center mark to the sketch entity. As the sketch circle is driven from the edge of the hole it will move with it and so will the center mark.
Regards.