My supervisor was busy but I never felt that i was bothering him. I think the initial dissertation brief that was shared by the university helped to iron out expectations and hence alleviated a lot of disappointments. eg it was clear to me that this was my dissertation and I was the one to do the work... not him. So my questions to him were mainly asking for advice and not to do my literature search for instance.
On the other hand, his communication to me was direct, specific and although sometimes he called me out, it was always with a lot of respect and compassion.