I have a WD 320GB external drive and a WD 1TB external drive. I would like to backup my 320GB on a regular basis. I have tried using the built in compressor in mac, but that fails saying unable to compress a file. I have also tried many other mac compressors and had no success. What is the best way to backup my external drive? Just copy and past the files over? Or to use a programme? By the way, I am open to windows ideas as well.
Edit: I would like to back up my 320GB to my 1TB on a regular basis.

