If you copy all your files to the seagate and the disk has not enough space, I reckon there is allready a lot of stuff on the seagate. Make sure there is enough room for it first by removing unwanted stuff, then select all the files and copy it into the seagate. It will take quite some space, check how much you will need by checking how much is on the Biab disk. I can't tell exactly, since I have the *.wma files only, but giving it the approx. 1:10 packed ratio, the audiofiles probably allready will take 350-400 Gb. So you really will need most of the Seagate's diskspace there.

I'll be back...