Several jobs ago, we were in the data center and doing this came up. We had an idle disk shelf with which to test, so we started up a bulk IO operation (`dd` or

Several jobs ago, we were in the data center and doing this came up. We had an idle disk shelf with which to test, so we started up a bulk IO operation (`dd` or something; I don't remember what, specifically), and watched the dip in the IO rate correlate perfectly with someone crouching next to the shelf and screaming at it.