This program does a random walk over the entire (raw) disk, reading a 4K block. This provides several exercises of the disk and the I/O layers. If nothing else, it makes lots of noise and heat, and the all-important blinking lights that show the boss that you're getting lots of work done.
I had a mode in place to do write-after-read, and then realized that I'd have to check and see if the device was mounted to avoid evil race condition errors, and then decided to skip the idea for now. I figure, the read-only mode is a pretty good test, at least for now.
molest.pl -d /dev/sdd -n 4096 molest.pl -d /dev/hda