GTA V, Install Only One Disk
A brief article on Eurogamer has said that Rockstar is warning gamers not to install both disks on the Xbox 360. GTA V comes on two disks, an install and play disk, it’s recommended you do NOT install the play disk.
At the moment, there are just tweets to people who have asked about the installing of the game…
— Rockstar Support (@RockstarSupport) September 16, 2013