Artem S. Tashkinov recently encountered a
problem that will be familiar to at least some LWN readers.  Plug a slow
storage device (a USB stick, say, or a media player) into a Linux machine
and write a lot of data to it.  The entire system proceeds to just hang,
possibly for minutes.  Things eventually come back, but, by then, the user
may well have given up in disgust and gone for a beer or two; by the time
the system is usable again, that user may well have lost interest.