Mounting a USB External HD with ExFAT formatting in Red Hat Linux

Name is slightly misleading, it's actually Checkpoint GAIA, but red hat linux methods should be applicable as that's the base.

I'm trying to mount an external HD 4 TB in size to backup log files from this box before it is reformatted for an upgrade. However, I don't seem to see the HD in dmesg. I do see some large swap space in /dev/sdb1, but when I try and mount it, it tells me that's it's swap space and nothing happens.

What could I be doing wrong, and what is the best way to find where usb devices are in /dev so I can mount them (this is a general question)?