We all know that conventional rotating hard disk drives aren't the sturdiest gizmos in the world. We're trained to treat our laptops gingerly when they're running, and many laptops are equipped with motion sensors that move the disk heads away from the data tracks if the machine is bumped or dropped.
But I've just learned that disk drives are more sensitive to minor vibrations than I thought. A blog post titled "Unusual disk latency" by Sun engineer Brendan Gregg describes how disk drives can go idle for relatively long periods of time-- over half a second-- when someone shouts at them!
The post even includes a video demonstration of the discovery.