[RndTbl] hard drive failure curve

[Trevor Cordes]

On 2014-09-03 Adam Thompson wrote:
> The obvious analogy that for obvious reasons* won't have occurred to
> you: cars.  If you don't get a lemon, it's probably good for a while,
> but eventually starts to break down. Also, historically, humans - at
> least in ages and places where infant mortality is/was a significant
> drag on population growth.

The Cars example is imperfect, because, as you said "it's good for a
while", but with hard drives I find that the near-zero-failure part of
the bathtub, if it even exists for HDDs, is abominably short, like 6
months.  Most quality cars these days (ones ranked high in Consumer
Reports reliability) should be nearly trouble-free for 5 years.

Here's my interpretation of the HD curve (monospace required):

|
|                            ____________________________
\                 __________/
 \      _________/
  \    /
   \__/

The main point being that after (maybe) a short reprieve, the failure
probability immediately ramps up to and sits at an unacceptable number
(like 15%) nearly forever, with but a tiny increment after each
additional year.  Whether there is a bathtub end after 10-20 years, is
up for debate.  (Brad and I have Atari ST drives from 30 years ago that
still operate, for example.)

Surely if you ASCII'd a modern car graph it wouldn't quite fit?

Your human being analogy is probably much closer to what I'm looking
for, but that one definitely has an abrupt bathtub hockey-stick at the
right hand side :-)  With humans, make it past the first tricky year
and you probably have a small chance that stays relatively static for
dozens of years of contracting a terminal illness or getting hit by a
bus.  Not as straight-forward as a "light bulb" example as I was
looking for (as it requires some thought and reflection) but pretty
good.

Surely, though, in the world of consumer items something else must be
just like hard drives?