I am wondering why...

When I try to copy my Event (big event 2.1 TB) to an external Harddrive, my internal hard disk runs out of space during the processing stage, any one have some wisdom they can pass along?

I have a Mac Pro

12 core 32 GB RAM

running

Mac OS X Lion 10.7.5

Nobody I have asked yet seems to know anything about FCPX creating temporary files on the home directory during the copying of events, but I don't know what else might be causing my memory to evaporate during the processing then return once that copying is aborted.

Thanks in advacne for any help you can give.