According to leaked packaging from Japan, Red Dead Redemption 2 will require 2 discs on PS4 to install the game.

We recently found out that the game would be 88-89GB in file size on both PlayStation 4 and Xbox One, however we had no idea if that meant the release of two discs with the game for physical purchasers. It seems that this will be the case, according to a leaked cover packaging photo.