What happen if I connect a hard drive bigger than 2tb to the xbox 360?

If the game is bigger than 4 GB, you will need either the official Xbox 360 hard drive, which can be inserted into the console or an external USB 2.0 hard drive which can have a maximum capacity of 2TB.

you could buy an external hard drive to put the data on as you can get bigger than what the xbox already has, example 1 TB would be good as they can sometimes be cheaper than a bigger hard drive for the 360 and they are really useful because its then backed
up and you can get rid off what you dont need

My son is needing an external hard drive (2TB) for his old Xbox 360s. What do you recommend?

Unfortunately the hard drive is bad . It happens sometimes. Which seagate drive do you have ? An xbox one , a seagate sllim plus , essential, etc. I recommend just getting another external hard drive. Why are you mismatching the sdd and hdd the sdd is
much faster than the hdd. Im assuming the ssd is only 1 tb or not bigger than 2tb because good ones tend to cost a bit. Just get you a good hub and add a few 4tb drives to it if you need more room i have 20 tb on my xbox I have a 8tb unit with three usb connections
4tb on the three . Just buy a good external drive , they all fail eventually depending how long you have them of course and the demand you put on it.

You can now purchase and add an external hard drive up to 2 TB in size to your 360 console.

majornelson.com/.../xbox-360-system-update-now-available-adds-support-for-2tb-hard-drives