Alberto Ricci writes, "Pressing command-S while (or right before you click Start) Disk First Aid is scanning a disk brings up a progress window that explains what it's doing. It's there from the old days, when Disk First Aid was another program, which was then acquired by Apple. The first program had a menu choice; Disk First Aid now doesn't show it, but it's still there. And, as you may guess looking at the "hidden" window, the program was Scavenger." [It's interesting finding out what Disk First Aid is doing after all these years of wondering if it did anything at all. -Adam]

Information from:
Alberto Ricci -- FRICCI@polito.it