Tach' Uwe
No, it doesn't sound normal. FWIW, I had install times of less than 2 hours on two intel macs - albeit, this was installing the L9 update over L8, IIRC the L9 installer recognized that much of the content which is common to both Logic Studio I and II was already present, and deselected it. If you are installing on a fresh system it may take longer, but 21 hours :eeek:
HTH, kind regards
Mark