Is there a way to prevent my Mac from sleeping during a file copy?

I'm copying a lot of files (over 700 GB) and it takes hours to complete. Is there a way to keep the Mac from sleeping before the copy process completes? I don't want to sit by the computer and moving my mouse from time to time. I tried to set my Energy Saver settings as: But sometimes it still dies. So currently, I have to sit by the laptop and wait.