On Sat, Jun 27, 2009 at 06:42:16PM +0200, Soren Orel wrote: > > Can I give a priority for the copy, so that I could use my PC when I'm > backing up my files? Right now, I'm copying in midnight commander. see: man ionice It might be some sort of USB problem or a problem with MC, though. What does top show about the copy process, does it use a lot of CPU time? If so, check out man renice ...