Having a small SSD disk for your operating system seems a bad practice to perform iTunes backup on the default directory path. You can’t change backup folder from itunes so this is a solution a found to keep my system disk with lots of space. (actually gained ~50GB of space).
Fisrt find that back up locations:
(replace XX with your user account name)
This path may change on different operating systems. (currently displaying path for Windows 8.1)
Secondly choose another disk with lots of free space. (e.x. E:\)
Move contents of
to a new folder.
Go on directory up and delete backup folder.
Lastly run this handy command.
mklink /d Backup "d:\backupItunes\"
This way you create a symbolic link, something like a virtual directory to the new path.